Optimization of artemether-loaded NLC for intranasal delivery using central composite design

Application of quality by design in optimization of nanoformulations: Principle, perspectives and practices

Nanoparticulate drug delivery systems (NDDS) based nanoformulations have emerged as promising drug delivery systems. Various NDDS-based formulations have been reported such as polymeric nanoparticles (NPs), nanoliposomes, solid lipid NPs, nanocapsules, liposomes, self-nano emulsifying drug delivery systems, pro liposomes, nanospheres, microemulsion, nanoemulsion, gold NPs, silver NPs and nanostructured lipid carrier. They have shown numerous advantages such as enhanced bioavailability, aqueous solubility, permeability, controlled release profile, and blood-brain barrier (BBB) permeability. This advantage of NDDS can help to deliver pure drugs to the target site. However, the formulation of nanoparticles is a complex process that requires optimization to ensure product quality and efficacy. Quality by Design (QbD) is a systemic approach that has been implemented in the pharmaceutical industry to improve the quality and reliability of drug products. QbD involves the optimization of different parameters like zeta potential (ZP), particle size (PS), entrapment efficiency (EE), polydispersity index (PDI), and drug release using statistical experimental design. The present article discussed the detailed role of QbD in optimizing nanoformulations and their advantages, advancement, and applications from the industrial perspective. Various case studies of QbD in the optimization of nanoformulations are also discussed.

Nose-to-Brain Drug Delivery and Physico-Chemical Properties of Nanosystems: Analysis and Correlation Studies of Data from Scientific Literature

Background

In the last few decades, nose-to-brain delivery has been investigated as an alternative route to deliver molecules to the Central Nervous System (CNS), bypassing the Blood-Brain Barrier. The use of nanotechnological carriers to promote drug transfer via this route has been widely explored. The exact mechanisms of transport remain unclear because different pathways (systemic or axonal) may be involved. Despite the large number of studies in this field, various aspects still need to be addressed. For example, what physicochemical properties should a suitable carrier possess in order to achieve this goal? To determine the correlation between carrier features (eg, particle size and surface charge) and drug targeting efficiency percentage (DTE%) and direct transport percentage (DTP%), correlation studies were performed using machine learning.

Methods

Detailed analysis of the literature from 2010 to 2021 was performed on Pubmed in order to build "NANOSE" database. Regression analyses have been applied to exploit machine-learning technology.

Results

A total of 64 research articles were considered for building the NANOSE database (102 formulations). Particle-based formulations were characterized by an average size between 150-200 nm and presented a negative zeta potential (ZP) from -10 to -25 mV. The most general-purpose model for the regression of DTP/DTE values is represented by Decision Tree regression, followed by K-Nearest Neighbors Regressor (KNeighbor regression).

Conclusion

A literature review revealed that nose-to-brain delivery has been widely investigated in neurodegenerative diseases. Correlation studies between the physicochemical properties of nanosystems (mean size and ZP) and DTE/DTP parameters suggest that ZP may be more significant than particle size for DTP/DTE predictability.

Box-Behnken Design-Based Optimization and Evaluation of Lipid-Based Nano Drug Delivery System for Brain Targeting of Bromocriptine

Bromocriptine (BCR) presents poor bioavailability when administered orally because of its low solubility and prolonged first-pass metabolism. This poses a significant challenge in its utilization as an effective treatment for managing Parkinson's disease (PD). The utilization of lipid nanoparticles can be a promising approach to overcome the limitations of BCR bioavailability. The aim of the research work was to develop and evaluate bromocriptine-loaded solid lipid nanoparticles (BCR-SLN) and bromocriptine-loaded nanostructured lipid carriers (BCR-NLC) employing the Box-Behnken design (BBD). BCR-SLNs and BCR-NLCs were developed using the high-pressure homogenization method. The prepared nanoparticles were characterized for particle size (PS), polydispersity index (PDI), and entrapment efficiency (EE). In vitro drug release, cytotoxicity studies, in vivo plasma pharmacokinetic, and brain distribution studies evaluated the optimized lipid nanoparticles. The optimized BCR-SLN had a PS of 219.21 ± 1.3 nm, PDI of 0.22 ± 0.02, and EE of 72.2 ± 0.5. The PS, PDI, and EE of optimized BCR-NLC formulation were found to be 182.87 ± 2.2, 0.16 ± 0.004, and 83.57 ± 1.8, respectively. The in vitro release profile of BCR-SLN and BCR-NLC showed a biphasic pattern, immediate release, and then trailed due to the sustained release. Furthermore, a pharmacokinetic study indicated that both the optimized BCR-SLN and BCR-NLC formulations improve the plasma and brain bioavailability of the drug compared to the BCR solution. Based on the research findings, it can be concluded that the BCR-loaded lipid nanoparticles could be a promising carrier by enhancing the BBB penetration of the drug and helping in the improvement of the bioavailability and therapeutic efficacy of BCR in the management of PD.

Formulation and characterization of polymeric nanoparticle of Rivastigmine for effective management of Alzheimer's disease

Memory loss or dementia is a progressive disorder, and one of its common forms is Alzheimer's disease (AD), effecting mostly middle aged and older adults. In the present study, we developed Rivastigmine (RIV) nanoparticles using poly(lactic-co-glycolic acid) (RIV-loaded PLGA NPs) and polyvinyl alcohol (PVA). The prepared RIV-PLGA nanoparticles was evaluated for the management of Alzheimer's disease (AD). The nanoparticles were prepared by the slightly modified nano-precipitation technique. The developed formulations were evaluated for particle size, zeta potential (ZP), polydispersibility index (PDI) and surface morphology and drug content. The experimental result revealed that prepared RIV-loaded PLGA NPs (F1) was optimized having particle size (61.2 ± 4.6 nm), PDI (0.292), ZP (-11.2 ± 1.2). SEM study confirms the prepared nanoparticles depicted non-aggregated as well smooth surface particles without any fracture. This formulation (F1) was further assessed for in vivo studies on animal model. A pharmacological screening on an animal model of Alzheimer's disease revealed that RIV-loaded PLGA NPs formulations treat CNS disorders like Alzheimer's effectively. In addition to that, an in-vivo brain cholinesterase estimation study found that, animals treated with optimized formulation significantly (p < 0.01) reduced brain cholinesterase activity when compared to scopolamine-treated animals. According to the above results, it can be concluded that RIV-loaded PLGA NPs are ideal carriers for delivering the drug at a specific target site in the brain, thus may treat Alzheimer's disease efficiently and improve patient compliance.

Combining the potential of 3D printed buccal films and nanostructured lipid carriers for personalised cannabidiol delivery

Cannabidiol (CBD) has been recognized for its numerous therapeutic benefits, such as neuroprotection, anti-inflammatory effects, and cardioprotection. However, CBD has some limitations, including unpredictable pharmacokinetics and low oral bioavailability. To overcome the challenges associated with CBD delivery, we employed Design of Experiments (DoE), lipid carriers, and 3D printing techniques to optimize and develop buccal film loaded with CBD-NLCs. Three-factor Box-Behnken Design was carried out to optimise the NLCs and analyse the effect of independent factors on dependent factors. The emulsification-ultrasonication technique was used to prepare the NLCs. A pressure-assisted micro-syringe printing technique was used to produce the films. The produced films were studied for physicochemical, and mechanical properties, release profiles, and predicted in vivo performance. The observed particle size of the NLCs ranged from 12.17 to 84.91 nm whereas the PDI varied from 0.099 to 0.298. Lipid and sonication time positively affected the particle size whereas the surfactant concentration was inversely related. CBD was incorporated into the optimal formulation and the observed particle size, PDI, and zeta potential for the CBD-NLCs were 94.2 ± 0.47 nm, 0.11 ± 0.01 and - 11.8 ± 0.52 mV. Hydroxyethyl cellulose (HEC)-based gel containing the CBD-NLCs was prepared and used as a feed for 3D printing. The CBD-NLCs film demonstrated a slow and sustained in vitro release profile (84. 11 ± 7.02% in 6 h). The predicted AUC0-10 h, Cmax, and Tmax were 201.5 µg·h/L, 0.74 µg/L, and 1.28 h for a film with 0.4 mg of CBD, respectively. The finding demonstrates that a buccal film of CBD-NLCs can be fabricated using 3D printing.

Physical characterization and bioavailability assessment of 5-fluorouracil-based nanostructured lipid carrier (NLC): In vitro drug release, Hemolysis, and permeability modulation

5-Fluorouracil (5-FU) is an anticancer agent belonging to BCS Class III that exhibits poor release characteristics and low retention in the biological system. The main objective of this investigation was to develop a drug delivery system, i.e., Nanostructure Lipid Carriers (NLCs) loaded with 5-FU to prolong its biological retention through 5-FU-loaded NLCs (5-FUNLC) were designed to manipulate physicochemical characteristics and assessment of in vitro and in vivo performance. The developed NLCs underwent comprehensive characterization, including assessments for particle size, zeta potential, morphological evaluation, and FT-IR spectroscopy. Additionally, specific evaluations were conducted for 5-FUNLCs, encompassing analyses for encapsulation efficiency of the drug, release characteristics in PBS at pH 6.8, and stability study. The lipophilic character of 5-FUNLC was confirmed through the measurement of the partition coefficient (log P). 5-FUNLCs were observed as spherical-shaped particles with a mean size of 300 ± 25 nm. The encapsulation efficiency was determined to be 89%, indicating effective drug loading within the NLCs. Furthermore, these NLCs exhibited a sustained release nature lasting up to 3-4 h, indicating their potential for controlled drug release over time. Lipid components were biocompatible with the 5-FU to determine thermal transition temperature and show good stability for 30 days. Additionally, an in vitro hemolysis study that confirmed the system did not cause any destruction to the RBCs during intravenous administration. The drug's gut permeability was assessed utilizing the optimized 5-FUNLC (F2) in comparison to 5-FU through the intestine or gut sac model (in the apical to basolateral direction, A → B). The permeability coefficient was measured as 4.91 × 10-5 cm/h with a significant difference. Additionally, the antioxidant potential of the NLCs was demonstrated through the DPPH method. The NLCs' performance was further assessed through in vivo pharmacokinetic studies on Wistar Rats, resulting in a 1.5-fold enhancement in their activity compared to free 5-FU. These NLCs offer improved drug solubility and sustained release, which collectively contribute to enhanced therapeutic outcomes and modulate bioavailability. The study concludes by highlighting the potential of 5-FUNLC as an innovative and efficient drug delivery system. The findings suggest that further preclinical investigations are warranted, indicating a promising avenue for the development of more effective and well-tolerated treatments for cancer.

Formulation and optimization of a single-layer coat for targeting budesonide pellets to the descending Colon

The current budesonide formulations are inadequate for addressing left-sided colitis, and patients might hesitate to use an enema for a prolonged time. This study focuses on developing a single-layer coating for budesonide pellets targeting the descending colon. Pellets containing budesonide (1.5%w/w), PVP K30 (5%w/w), lactose monohydrate (25%w/w) and Avicel pH 102 (68.5%w/w) were prepared using extrusion spheronization technique. Coating formulations were designed using response surface methodology with pH and time-dependent Eudragits. Dissolution tests were conducted at different pH levels (1.2, 6.5, 6.8, and 7.2). Optimal coating formulation, considering coating level and the Eudragit (S + L) ratio to the total coating weight, was determined. Budesonide pellets were coated with the optimized composition and subjected to continuous dissolution testing simulating the gastrointestinal tract. The coating, with 48% S, 12% L, and 40% RS at a 10% coating level, demonstrated superior budesonide delivery to the descending colon. Coated pellets had a spherical shape with a uniform 30 µm thickness coating, exhibiting pH and time-dependent release. Notably, zero-order release kinetics was observed for the last 9 h in colonic conditions. The study suggests that an optimized single-layer coating, incorporating pH and time-dependent polymers, holds promise for consistently delivering budesonide to the descending colon.

QbD-driven development of phospholipid-embedded lipidic nanocarriers of raloxifene: extensive in vitro and in vivo evaluation studies

Raloxifene (RLX) is popularly indicated in treatment of osteoporosis and prevention of breast cancer. Owing to its poor aqueous solubility, high pre-systemic metabolism, intestinal glucuronidation, and P-glycoprotein (P-gp) efflux, however, it demonstrates low (< 2%) and inconsistent oral bioavailability. The current work, Quality by Design (QbD)-driven development of phospholipid-embedded nanostructured lipidic carriers (NLCs) of RLX, accordingly, was undertaken to potentiate its lymphatic uptake, augment oral bioavailability, and possibly reduce drug dosage. Factor screening and failure mode effect analysis (FMEA) studies were performed to delineate high-risk factors using solid lipid (glyceryl monostearate), liquid lipid (vitamin E), and surfactant (Tween 80). Response surface optimization studies were performed employing the Box-Behnken design. Mathematical and graphical methods were adopted to embark upon the selection of optimized NLCs with various critical quality attributes (CQAs) of mean particle size as 186 nm, zeta potential of - 23.6 mV, entrapment efficiency of 80.09%, and cumulative drug release at 12 h of 83.87%. The DSC and FTIR studies, conducted on optimized NLCs, indicated successful entrapment of drug into the lipid matrix. In vitro drug release studies demonstrated Fickian diffusion mechanism. In vivo pharmacokinetic studies in rats construed significant improvement in AUC0-72 h (4.48-folds) and in Cmax (5.11-folds), unequivocally indicating markedly superior (p < 0.001) oral bioavailability of RLX-NLCs vis-à-vis marketed tablet formulation. Subsequently, level "A" in vitro/in vivo correlation (IVIVC) was also successfully attempted between the percentages of in vitro drug dissolved and of in vivo drug absorbed at the matching time points. In vitro cytotoxicity and cellular uptake studies also corroborated higher efficacy and successful localization of coumarin-6-loaded NLCs into MG-63 cells through microfluidic channels.

Quality by design endorsed atorvastatin-loaded nanostructured lipid carriers embedded in pH-responsive gel for melanoma

AIM

Our aim was to repurpose atorvastatin for melanoma by encapsulating in a nanostructured lipid carrier matrix to promote tumour cell internalisation and skin permeation. pH-responsive chitosan gel was employed to restrict At-NLCs in upper dermal layers.

METHODS

We utilised a quality by design approach for encapsulating At within the NLC matrix. Further, cellular uptake and cytotoxicity was evaluated along with pH-responsive release and ex vivo skin permeation.

RESULTS

Cytotoxicity assay showed 3.13-fold enhanced cytotoxicity on melanoma cells compared to plain drug with nuclear staining showing apoptotic markers. In vitro, release studies showed 5.9-fold rapid release in chitosan gel matrix at pH 5.5 compared to neutral pH.

CONCLUSIONS

At-NLCs prevented precipitation, promoted skin permeation, and SK-MEL 28 cell internalisation. The localisation of NLCs on the upper dermal layer due to electrostatic interactions of skin with chitosan gel diminished the incidence of untoward systemic effects.

Design and evaluations of a nanostructured lipid carrier loaded with dopamine hydrochloride for intranasal bypass drug delivery in Parkinson's disease

AIM

The goal of this study is to optimisation and evaluation of dopamine-loaded NLC (NLC-DOPA) for achieve dopamine concentrations into brain for treatment of Parkinson's disease which causes progressive neuronal death.

METHOD

NLC-DOPA prepared by homogenisation method using solid lipids (Cholesterol and Soya lecithin), liquid lipid (Oleic acid) and surfactant (Poloxamer- 188) as major excipients, optimised by central composite design using design expert-13 software. The optimised formulations were characterised by particle size, zeta potential, entrapment efficiency, SEM, TEM, FTIR, DSC, XRD, stability study and in-vitro drug release. The histopathology of rat brain tissues and goat nasal tissues were performed. The ex-vivo (permeability and nasal ciliotoxicity study) and in vivo pharmacodynamics study were also accomplished to determine its efficacy and potency of NLC.

RESULT

The NLC-DOPA formulations were optimised in particle size and (EE)% with range from 85.53 ± 0.703 to 106.11 ± 0.822 nm and 82.17 ± 0.794 to 95.45 ± 0.891%, respectively. The optimised formulation F11 showing best goodness-fitted model kinetic, followed by Korsmeyer-Peppas equation and zero order kinetic. The SEM and TEM confirmed the spherical and smooth morphology of formulation. FTIR and DSC spectra were given compatibility of compound and XRD diffractograms confirmed the amorphous nature. An ex-vivo study was showed the high permeability coefficient (6.67*1 0 -4 cm/min, which is twice, compare to pure drug) and there was no damage in nasal mucosa, confirmed by the ciliotoxicity study. In-vivo study was shown significant effects of optimised NLC-DOPA on locomotor activity, force-swimming test and neurochemical assessment using rotenone induced Parkinson's model on Albino Wistar rats.

CONCLUSION

NLC-DOPA was prepared and optimised successfully with increased bioavailability of drug from the NLC into brain with reduce toxicity in effective treatment of Parkinson's disease.

Quality by design engineered, enhanced anticancer activity of temozolomide and resveratrol coloaded NLC and brain targeting via lactoferrin conjugation in treatment of glioblastoma

The most dangerous type of high-grade astrocytoma is glioblastoma multiforme. The objective of the work was to engineer lactoferrin conjugated temozolomide and resveratrol co-loaded NLC for the treatment of glioblastoma using intranasal delivery for brain targeting. Synergistic activity of temozolomide and resveratrol was determined using combination index method and 1:1 ratio was selected. QbD approach was used to formulate and optimize NLC, with minimum particle size, maximum transmittance and entrapment efficiency using Central Composite Rotable Design (CCRD) method. The optimized LTR-NLC had desired average particle size (209.3 nm), narrow PDI along, high percentage transmittance (>95%) and better entrapment efficiency (95.26% of TEM and 87.59% of RES). From ex-vivo permeation studies it was found that the permeation at 24 h was 77.43 %, and 88.55 % from LTR-NLC and 25.76 % and 31.10% from suspension for resveratrol and temozolomide respectively. In comparison to drug suspension, NLC had nearly 3-fold increase in drug penetration. IC50 value was also significantly better in the groups treated with LTR-NLC. Hence it can be concluded that LTR-NLC may be an effective formulation for the treatment of glioblastoma, according to the findings of this investigation.

Development of Atomoxetine-Loaded NLC In Situ Gel for Nose-to-Brain Delivery: Optimization, In Vitro, and Preclinical Evaluation

The present study investigates the brain-targeted efficiency of atomoxetine (AXT)-loaded nanostructured lipid carrier (NLC)-laden thermosensitive in situ gel after intranasal administration. AXT-NLC was prepared by the melt emulsification ultrasonication method and optimized using the Box-Behnken design (BBD). The optimized formulation (AXT-NLC) exhibited particle size PDI, zeta potential, and entrapment efficiency (EE) of 108 nm, 0.271, -42.3 mV, and 84.12%, respectively. The morphology of AXT-NLC was found to be spherical, as confirmed by SEM analysis. DSC results displayed that the AXT was encapsulated within the NLC matrix. Further, optimized NLC (AXT-NLC13) was incorporated into a thermosensitive in situ gel using poloxamer 407 and carbopol gelling agent and evaluated for different parameters. The optimized in situ gel (AXT-NLC13G4) formulation showed excellent viscosity (2532 ± 18 Cps) at 37 °C and formed the gel at 28-34 °C. AXT-NLC13-G4 showed a sustained release of AXT (92.89 ± 3.98% in 12 h) compared to pure AXT (95.47 ± 2.76% in 4 h). The permeation flux through goat nasal mucosa of AXT from pure AXT and AXT-NLC13-G4 was 504.37 µg/cm²·h and 232.41 µg/cm²·h, respectively. AXT-NLC13-G4 intranasally displayed significantly higher absolute bioavailability of AXT (1.59-fold higher) than intravenous administration. AXT-NLC13-G4 intranasally showed 51.91% higher BTP than pure AXT (28.64%) when administered via the same route (intranasally). AXT-NLC13-G4 showed significantly higher BTE (207.92%) than pure AXT (140.14%) when administered intranasally, confirming that a high amount of the AXT reached the brain. With the disrupted performance induced by L-methionine, the AXT-NLC13-G4 showed significantly (p < 0.05) better activity than pure AXT as well as donepezil (standard). The finding concluded that NLC in situ gel is a novel carrier of AXT for improvement of brain delivery by the intranasal route and requires further investigation for more justification.

Nose-to-brain drug delivery for the treatment of CNS disease: New development and strategies

Delivering drugs to the brain has always been a challenging task due to the restrictive properties of the blood-brain barrier (BBB). Intranasal delivery is therefore emerging as an efficient method of administration, making it easy to self-administration and thus provides a non-invasive and painless alternative to oral and parenteral administration for delivering therapeutics to the central nervous system (CNS). Recently, drug formulations have been developed to further enhance this nose-to-brain transport, primarily using nanoparticles (NPs). Therefore, the purposes of this review are to highlight and describe the anatomical basis of nasal-brain pathway and provide an overview of drug formulations and current drugs for intranasal administration in CNS disease.

Evaluation of Pharmacokinetics, Biodistribution, and Antimalarial Efficacy of Artemether-Loaded Polymeric Nanorods

Artemether oily injection is recommended for the treatment of severe malaria by the intramuscular route. The major limitations of the artemisinin combination therapy are erratic absorption from the injection site and high dosing frequency due to a very short elimination half-life of the drug. Advanced drug delivery systems have shown significant improvement in the current malaria therapy; the desired drug concentration within infected erythrocytes is yet the major challenge. Recently, we have reported the fabrication of artemether-loaded polymeric nanorods for intravenous malaria therapy which was found to be biocompatible with THP-1 monocytes and rat erythrocytes. The objective of the present study was the evaluation of pharmacokinetics, biodistribution, and antimalarial efficacy of artemether-loaded polymeric nanorods. Scanning electron microscopy and confocal microscopy studies revealed that both nanospheres and nanorods were adsorbed onto the surface of rat erythrocytes after an incubation of 10 min. After intravenous administration to rats, artemether nanorods showed higher plasma concentration and lower elimination rate of artemether when compared with nanospheres. The biodistribution studies showed that, at 30 min, the liver concentration of DiR-loaded nanospheres was higher than that of DiR-loaded nanorods after intravenous administration to BALB/c mice. The in vitro schizont inhibition study showed that both nanorods and nanospheres exhibited concentration-dependent parasitic inhibition, wherein at lower concentrations (2 ppm), nanorods were more effective than nanospheres. However, at higher concentrations, nanospheres were found to be more effective. Nanorods showed higher chemosuppression on day 5 and day 7 than nanospheres and free artemether when studied with the Plasmodium berghei mouse model. Moreover, the survival rate of P. berghei infected mice was also found to be higher after treatment with artemether nanoformulations when compared with free artemether. In conclusion, polymeric nanorods could be a promising next-generation delivery system for the treatment of malaria.

Intranasal Delivery of Functionalized Polymeric Nanomaterials to the Brain

Intravenous delivery of nanomaterials containing therapeutic agents and various cargos for treating neurological disorders is often constrained by low delivery efficacy due to difficulties in passing the blood-brain barrier (BBB). Nanoparticles (NPs) administered intranasally can move along olfactory and trigeminal nerves so that they do not need to pass through the BBB, allowing non-invasive, direct access to selective neural pathways within the brain. Hence, intranasal (IN) administration of NPs can effectively deliver drugs and genes into targeted regions of the brain, holding potential for efficacious disease treatment in the central nervous system (CNS). In this review, current methods for delivering conjugated NPs to the brain are primarily discussed. Distinctive potential mechanisms of therapeutic nanocomposites delivered via IN pathways to the brain are then discussed. Recent progress in developing functional NPs for applications in multimodal bioimaging, drug delivery, diagnostics, and therapeutics is also reviewed. This review is then concluded by discussing existing challenges, new directions, and future perspectives in IN delivery of nanomaterials.

Sorafenib-loaded nanostructured lipid carriers for topical ocular therapy of corneal neovascularization: development, in-vitro and in vivo study

Sorafenib (SRB), a multikinase inhibitor, is effective in reducing experimental corneal neovascularization (CNV) after oral administration; however, its therapeutic use in ocular surface disorders is restricted due to poor solubility and limited bioavailability. This study aimed to develop and optimize SRB-loaded nanostructured lipid carriers (SRB-NLCs) for topical ocular delivery by a central composite design response surface methodology (CCD-RSM). It was spherical and uniform in morphology with an average particle size of 111.87 ± 0.93 nm and a narrow size distribution. The in vitro drug release from the released SRB-NLC formulation was well fitted to Korsmeyer Peppas release kinetics. The cell counting kit-8 (CCK-8) cell viability assay demonstrated that SRB-NLC was not obviously cytotoxic to human corneal epithelial cells (HCECs). An in vivo ocular irritation test showed that SRB-NLC was well tolerated by rabbit eyes. Ocular pharmacokinetics revealed 6.79-fold and 1.24-fold increase in the area under concentration-time curves (AUC_0-12h) over 12 h in rabbit cornea and conjunctiva, respectively, treated with one dose of SRB-NLC compared with those treated with SRB suspension. Moreover, SRB-NLC (0.05% SRB) and dexamethasone (0.025%) similarly suppressed corneal neovascularization in mice. In conclusion, the optimized SRB-NLC formulation demonstrated excellent physicochemical properties and good tolerance, sustained release, and enhanced ocular bioavailability. It is safe and potentially effective for the treatment of corneal neovascularization.

Strategies to Improve Drug Strength in Nasal Preparations for Brain Delivery of Low Aqueous Solubility Drugs

Intranasal administration is a promising route for brain drug delivery. However, it can be difficult to formulate drugs that have low water solubility into high strength intranasal solutions. Hence, the purpose of this work was to review the strategies that have been used to increase drug strength in intranasal liquid formulations. Three main groups of strategies are: the use of solubilizers (change in pH, complexation and the use cosolvents/surfactants); incorporation of the drugs into a carrier nanosystem; modifications of the molecules themselves (use of salts or hydrophilic prodrugs). The use of high amounts of cosolvents and/or surfactants and pH decrease below 4 usually lead to local adverse effects, such as nasal and upper respiratory tract irritation. Cyclodextrins and (many) different carrier nanosystems, on the other hand, could be safer for intranasal administration at reasonably high concentrations, depending on selected excipients and their dose. While added attributes such as enhanced permeation, sustained delivery, or increased direct brain transport could be achieved, a great effort of optimization will be required. On the other hand, hydrophilic prodrugs, whether co-administered with a converting enzyme or not, can be used at very high concentrations, and have resulted in a fast prodrug to parent drug conversion and led to high brain drug levels. Nevertheless, the choice of which strategy to use will always depend on the characteristics of the drug and must be a case-by-case approach.

Pharmacokinetics and Pharmacodynamics of Intranasal Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for Nose-to-Brain Delivery

Nose-to-brain drug delivery has been of great interest for the treatment of many central nervous system (CNS) diseases and psychiatric disorders over past decades. Several nasally administered formulations have been developed to circumvent the blood-brain barrier and directly deliver drugs to the CNS through the olfactory and trigeminal pathways. However, the nasal mucosa's drug absorption is insufficient and the volume of the nasal cavity is small, which, in combination, make nose-to-brain drug delivery challenging. These problems could be minimized using formulations based on solid lipid nanoparticles (SLNs) or nanostructured lipid carriers (NLCs), which are effective nose-to-brain drug delivery systems that improve drug bioavailability by increasing drug solubility and permeation, extending drug action, and reducing enzymatic degradation. Various research groups have reported in vivo pharmacokinetics and pharmacodynamics of SLNs and NLCs nose-to-brain delivery systems. This review was undertaken to provide an overview of these studies and highlight research performed on SLN and NLC-based formulations aimed at improving the treatment of CNS diseases such neurodegenerative diseases, epilepsy, and schizophrenia. We discuss the efficacies and brain targeting efficiencies of these formulations based on considerations of their pharmacokinetic parameters and toxicities, point out some gaps in current knowledge, and propose future developmental targets.

Nanocarrier mediated drug delivery as an impeccable therapeutic approach against Alzheimer's disease

For the past several years, dementia, is one of the predominantly observed groups of symptoms in a geriatric population. Alzheimer's disease (AD) is a progressive memory related neurodegenerative disease, for which the current Food and drug administration approved therapeutics are only meant for a symptomatic management rather than targeting the root cause of AD. These therapeutics belong to two classes, Acetylcholine Esterase inhibitors and N-methyl D-aspartate antagonist. Furthermore, to facilitate neuroprotective action in AD, the drugs are majorly expected to reach the specific target area in the brain for the desired efficacy. Thus, there is a huge requirement for drug discovery and development for facilitating the entry of drugs more in brain to exert a specific action. The very first line of defense and the major limitation for the entry of drugs into the brain is the Blood Brain Barrier, followed by Blood-Cerebrospinal Fluid Barrier. More than a barrier, these mainly act as selectively permeable membranes, which allows entry of specific molecules into the brain. Furthermore, specific enzymes result in the degradation of xenobiotics. All these mechanisms pose as hurdles in the way of effective drug delivery in the brain. Thus, novel techniques need to be harbored for the facilitation of the delivery of such drugs into the brain. Nanocarriers are advantageous for facilitating the specific targeted drug treatment in AD. As nanomedicines are one of the novels and most useful approaches for AD, thus the present review mainly focuses on understanding the advanced use of nanocarriers for targeted drug delivery in the management of AD.

Design and evaluation of nanostructured lipid carriers loaded with Salvia officinalis extract for Alzheimer's disease treatment

Considering the potential of Salvia officinalis in prevention and treatment of Alzheimer's disease (AD), as well as the ability of nanostructured lipid carriers (NLC) to successfully deliver drug molecules across blood-brain barrier (BBB), the objective of this study was design, development, optimization and characterization of freeze-dried salvia officinalis extract (FSE) loaded NLC intended for intranasal administration. NLC were prepared by solvent evaporation method and the optimization was carried out using central composite design (CCD) of experiments. Further, the optimized formulation (NLCo) was coated either with chitosan (NLCc) or poloxamer (NLCp). Surface characterization of the particles demonstrated a spherical shape with smooth exterior. Particle size of optimal formulations after 0.45 μm pore size filtration ranged from 127 ± 0.68 nm to 140 ± 0.74 nm. The zeta potential was -25.6 ± 0.404 mV; 22.4 ± 1.106 mV and - 6.74 ± 0.609 mV for NLCo, NLCc, and NLCp, respectively. Differential scanning calorimetry (DSC) confirmed the formation of NLC whereas Fourier-transform infrared spectroscopy confirmed the FSE encapsulation into particles. All formulations showcased relatively high drug loading (>86.74 mcg FSE/mg solid lipid) and were characterized by prolonged and controlled release that followed Peppas-Sahlin in vitro release kinetic model. Protein adsorption studies revealed the lowest adsorption of the proteins onto NLCp (43.53 ± 0.07%) and highest protein adsorption onto NLCc (55.97 ± 0.75%) surface. The modified ORAC assay demonstrated higher antioxidative activity for NLCo (95.31 ± 1.86%) and NLCc (97.76 ± 4.00%) as compared to FSE (90.30 ± 1.53%). Results obtained from cell cultures tests pointed to the potential of prepared NLCs for FSE brain targeting and controlled release.

Engineered Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as New Generations of Blood-Brain Barrier Transmitters

The blood-brain barrier (BBB) is considered as the most challenging barrier in brain drug delivery. Indeed, there is a definite link between the BBB integrity defects and central nervous systems (CNS) disorders, such as neurodegenerative diseases and brain cancers, increasing concerns in the contemporary era because of the inability of most therapeutic approaches. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have already been identified as having several advantages in facilitating the transportation of hydrophilic and hydrophobic agents across the BBB. This review first explains BBB functions and its challenges in brain drug delivery, followed by a brief description of nanoparticle-based drug delivery for brain diseases. A detailed presentation of recent progressions in optimizing SLNs and NLCs for controlled release drug delivery, gene therapy, targeted drug delivery, and diagnosis of neurodegenerative diseases and brain cancers is approached. Finally, the problems, challenges, and future perspectives in optimizing these carriers for potential clinical application were described briefly.

Convolutions in the rendition of nose to brain therapeutics from bench to bedside: Feats & fallacies

Brain, a subtle organ of multifarious nature presents plethora of physiological, metabolic and bio-chemical convolutions that impede the delivery of biomolecules and thereby resulting in truncated therapeutic outcome in pathological conditions of central nervous system (CNS). The absolute bottleneck in the therapeutic management of such devastating CNS ailments is the BBB. Another pitfall is the lack of efficient technological platforms (due to high cost and low approval rates) as well as limited clinical trials (due to failures of neuro‑leads in late-stage pipelines) for CNS disorders which has become a literal brain drain with poorest success rates compared to other therapeutic areas, owing to time consuming processes, tremendous convolutions and conceivable adverse effects. With the advent of intranasal delivery (via direct N2B or indirect nose to blood to brain), several novel drug delivery carriers viz. unmodified or surface modified nanoparticle based carriers, lipid based colloidal nanocarriers and drysolid/liquid/semisolid nanoformulations or delivery platforms have been designed as a means to deliver therapeutic agents (small and large molecules, peptides and proteins, genes) to brain, bypassing BBB for disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, schizophrenia and CNS malignancies primarily glioblastomas. Intranasal application offers drug delivery through both direct and indirect pathways for the peripherally administered psychopharmacological agents to CNS. This route could also be exploited for the repurposing of conventional drugs for new therapeutic uses. The limited clinical translation of intranasal formulations has been primarily due to existence of barriers of mucociliary clearance in the nasal cavity, enzyme degradation and low permeability of the nasal epithelium. The present review literature aims to decipher the new paradigms of nano therapeutic systems employed for specific N2B drug delivery of CNS drugs through in silico complexation studies using rationally chosen mucoadhesive polymers (exhibiting unique physicochemical properties of nanocarrier's i.e. surface modification, prolonging retention time in the nasal cavity, improving penetration ability, and promoting brain specific delivery with biorecognitive ligands) via molecular docking simulations. Further, the review intends to delineate the feats and fallacies associated with N2B delivery approaches by understanding the physiological/anatomical considerations via decoding the intranasal drug delivery pathways or critical factors such as rationale and mechanism of excipients, affecting the permeability of CNS drugs through nasal mucosa as well as better efficacy in terms of brain targeting, brain bioavailability and time to reach the brain. Additionally, extensive emphasis has also been laid on the innovative formulations under preclinical investigation along with their assessment by means of in vitro /ex vivo/in vivo N2B models and current characterization techniques predisposing an efficient intranasal delivery of therapeutics. A critical appraisal of novel technologies, intranasal products or medical devices available commercially has also been presented. Finally, it could be warranted that more reminiscent pharmacokinetic/pharmacodynamic relationships or validated computational models are mandated to obtain effective screening of molecular architecture of drug-polymer-mucin complexes for clinical translation of N2B therapeutic systems from bench to bedside.

Multi-disciplinary Approach for Drug and Gene Delivery Systems to the Brain

Drug delivery into the brain has for long been a huge challenge as the blood–brain barrier (BBB) offers great resistance to entry of foreign substances (with drugs inclusive) into the brain. This barrier in healthy individuals is protective to the brain, disallowing noxious substances present in the blood to get to the brain while allowing for the exchange of small molecules into the brain by diffusion. However, BBB is disrupted under certain disease conditions, such as cerebrovascular diseases including acute ischemic stroke and intracerebral hemorrhage, and neurodegenerative disorders including multiple sclerosis (MS), Alzheimer’s disease (AD), Parkinson’s disease (PD), and cancers. This review aims to provide a broad overview of present-day strategies for brain drug delivery, emphasizing novel delivery systems. Hopefully, this review would inspire scientists and researchers in the field of drug delivery across BBB to uncover new techniques and strategies to optimize drug delivery to the brain. Considering the anatomy, physiology, and pathophysiological functioning of the BBB in health and disease conditions, this review is focused on the controversies drawn from conclusions of recently published studies on issues such as the penetrability of nanoparticles into the brain, and whether active targeted drug delivery into the brain could be achieved with the use of nanoparticles. We also extended the review to cover novel non-nanoparticle strategies such as using viral and peptide vectors and other non-invasive techniques to enhance brain uptake of drugs.

Nanotherapeutics for Nose-to-Brain Drug Delivery: An Approach to Bypass the Blood Brain Barrier

Treatment of neurodegenerative diseases or other central nervous system (CNS) disorders has always been a significant challenge. The nature of the blood-brain barrier (BBB) limits the penetration of therapeutic molecules to the brain after oral or parenteral administration, which, in combination with hepatic metabolism and drug elimination and inactivation during its journey in the systemic circulation, decreases the efficacy of the treatment, requires high drug doses and often induces adverse side effects. Nose-to-brain drug delivery allows the direct transport of therapeutic molecules by bypassing the BBB and increases drug concentration in the brain. The present review describes mechanisms of nose-to-brain drug delivery and discusses recent advances in this area with especial emphasis on nanotechnology-based approaches.

Nose to Brain Delivery of Phenytoin Sodium Loaded Nano Lipid Carriers: Formulation, Drug Release, Permeation and In Vivo Pharmacokinetic Studies

An acute epileptic seizure is a seizure emergency fatal condition that requires immediate medical attention. IV phenytoin sodium remains the second line therapeutic agent for the immediate treatment of status epilepticus. Phenytoin sodium formulated as nanolipid carriers (NLCs) seems to be promising as an intranasal delivery system for controlling acute seizures. Three different nanosized phenytoin sodium loaded NLCs (<50 nm, 50-100 nm and >100 nm) were prepared by melt emulsification and was further characterised. In vitro drug release studies showed immediate drug release from phenytoin sodium loaded NLCs of <50 nm size, which is highly essential for acute seizure control. The ex vivo permeation study indicated greater permeation from <50 nm sized NLC through the olfactory epithelium compared to thecontrol drug solution. Invivo pharmacokinetic studies revealed higher drug concentration in CSF/brain within 5 min upon intranasal administration of <50 nm sized phenytoin sodium NLCs than the control drug solution and marketed IV phenytoin sodium, indicating direct and rapid nose to brain drug transport through the olfactory epithelium. The study has shown that formulation strategies can enhance olfactory uptake, and phenytoin sodium NLCs of desired particle sizes (<50 nm) offer promising potential for nose to brain direct delivery of phenytoin sodium in treating acute epileptic seizures.

Nanostructured Lipid Carriers for Intranasal Administration of Olanzapine in the Management of Schizophrenia

BACKGROUND

Olanzapine belongs to a new class of dual spectrum antipsychotic agents. It is known to show promise in managing both the positive and negative symptoms of schizophrenia. Drug delivery systems based on nanostructured lipid carriers (NLC) are expected to provide rapid nose-to-brain transport of this drug and improved distribution into and within the brain.

OBJECTIVE

The present study deals with the preparation and evaluation of olanzapine loaded NLC via the intranasal route for schizophrenia.

METHODS

Olanzapine-NLC were formulated through the solvent injection method using isopropyl alcohol as the solvent, stearic acid as solid lipid, and oleic acid as liquid lipid, chitosan as a coating agent, and Poloxamer 407 as a surfactant. NLC were characterized for particle size, polydispersity index, entrapment efficiency, pH, viscosity, X-ray diffraction studies, in-vitro mucoadhesion study, in- vitro release and ex-vivo permeation studies. The shape and surface morphology of the prepared NLC was determined through transmission electron microscopy. To detect the interaction of the drug with carriers, compatibility studies were also carried out.

RESULTS

Average size and polydispersity index of developed formulation S6 was 227.0±6.3 nm and 0.460, respectively. The encapsulation efficiency of formulation S6 was found to be 87.25%. The pH, viscosity, in-vitro mucoadhesion study, and in- vitro release of optimized olanzapine loaded NLC were recorded as 5.7 ± 0.05, 78 centipoise, 15±2 min, and 91.96%, respectively. In ex-vivo permeation studies, the percent drug permeated after 210 min was found to be 84.03%.

CONCLUSION

These results reveal the potential application of novel olanzapine-NLC in intranasal drug delivery system for the treatment of Schizophrenia.

Nanobiotechnological modules as molecular target tracker for the treatment and prevention of malaria: options and opportunity

Malaria is one of the major infectious diseases that remains a constant challenge to human being mainly due to the emergence of drug-resistant strains of parasite and also the availability of drugs, which are non-specific for their pharmacodynamic activity and known to be associated with multiple side effects. The disease has acquired endemic proportions in tropical countries where the hygienic conditions are not satisfactory while the environmental conditions favor the proliferation of parasite and its transmission, particularly through the female anopheles. It is obvious that to square up the problems, there is a need for designing and development of more effective drugs, which can combat the drug-resistant strains of the parasite. Molecular biology of the parasite and its homing into host cellular tropics provide multiple drug targets that could judiciously be considered for engineering and designing of new generation antimalarial drugs and also drug delivery systems. Though the recent reports document that against malaria parasite the vaccine could be developed, nevertheless, due to smart mutational change overs by the parasite, it is able to bypass the immune surveillance. The developed vaccine therefore failed to assure absolute protection against the malarial infection. In the conventional mode of treatment antimalarial drugs, the dose and dosage regimen that is followed at large crops up the contraindicative manifestations, and hence compromising the effective treatment. The emerging trends and new updates in contemporary biological sciences, material sciences, and drug delivery domain have enabled us with the availability of a multitude of mode and modules which could plunge upon the nanotechnology in particular to treat this challenging infection. The nanotechnology-based option may be tuned or customized as per the requirements to mark and target i.e. the infected RBCs, for targeted drug delivery.

Quality by design (QbD) optimization of diazepam-loaded nanostructured lipid carriers (NLC) for nose-to-brain delivery: Toxicological effect of surface charge on human neuronal cells

Diazepam is commonly used in the management of epileptic seizures, although it has limitations that can be overcome by using formulations that are easier to administer and capable of directing the drug to the brain. In this field, it has been reported that the use of nanostructured lipid carriers (NLC) via intranasal (or via nose-to-brain) promotes the targeting of drugs to the brain, improving the effectiveness of therapy. The aim of this work was to optimize two diazepam-loaded NLC formulations for nose-to-brain delivery, one with positive surface charge and one with negative surface charge. The quality by design (QbD) approach was used to design the experiments, where the quality target product profile (QTPP), the risk assessment and the critical quality attributes (CQAs) were defined to ensure safety, efficacy and quality of the final formulations. The experiments started with the optimization of critical material attributes (CMAs), related to the ratios of lipids and emulsifiers, followed by the selection of critical process parameters (CPPs), related to the production methods of the diazepam-loaded NLC formulation (ultrasound technique and high-pressure homogenization - HPH). Afterwards, the positive surface charge of the diazepam-loaded NLC was optimized. Finally, the biocompatibility with human neuronal cells of the formulation with a negative surface charge and of the formulation with a positive surface charge was evaluated. The results of the optimization of the CMAs showed that the ratios of lipids and emulsifiers more adequate were 6.7:2.9 and 4.2:0.3 (% w,w), respectively. Regarding the CPPs, HPH was considered the most suitable production method, resulting in an optimized diazepam-loaded NLC formulation (F1C15) with negative surface charge, showing particle size of 69.59 ± 0.22 nm, polydispersity index (PDI) of 0.19 ± 0.00, zeta potential (ZP) of -23.50 ± 0.24 mV and encapsulation efficiency (EE) of 96.60 ± 0.03 %. The optimized diazepam-loaded NLC formulation (F2A8) with positive surface charge had particle size of 124.40 ± 0.84 nm, PDI of 0.17 ± 0.01, ZP of 32.60 ± 1.13 mV and EE of 95.76 ± 0.24 %. In addition, the incorporation of diazepam in NLC resulted in a sustained release of the drug. No significant changes in particle size, PDI, ZP and EE were observed for the formulation F1C15, after 3 months of storage, whereas for formulation F2A8, particle size increased significantly. Biocompatibility studies showed that the formulation F2A8 was more cytotoxic than the formulation F1C15. Thereby, we conclude that the formulation F1C15 is more suitable for targeting the brain, when compared with the formulation F2A8. From the results of these studies, it can be confirmed that the QbD approach is an adequate and central tool to optimize NLC formulations.

Preparation, Characterization, and Anti-Cancer Activity of Nanostructured Lipid Carriers Containing Imatinib

Breast cancer is the most widespread malignancy in women worldwide. Nanostructured lipid carriers (NLCs) have proven effective in the treatment of cancer. NLCs loaded with imatinib (IMA) (NANIMA) were prepared and evaluated for their in vitro efficacy in MCF-7 breast cancer cells. The hot homogenization method was used for the preparation of NANIMAs. An aqueous solution of surfactants (hot) was mixed with a molten mixture of stearic acid and sesame oil (hot) under homogenization. The prepared NANIMAs were characterized and evaluated for size, polydispersity index, zeta potential, encapsulation efficiency, release studies, stability studies, and MTT assay (cytotoxicity studies). The optimized NANIMAs revealed a particle size of 104.63 ± 9.55 d.nm, PdI of 0.227 ± 0.06, and EE of 99.79 ± 0.03. All of the NANIMAs revealed slow and sustained release behavior. The surfactants used in the preparation of the NANIMAs exhibited their effects on particle size, zeta potential, encapsulation efficiency, stability studies, and release studies. The cytotoxicity studies unveiled an 8.75 times increase in cytotoxicity for the optimized NANIMAs (IC₅₀ = 6 µM) when compared to IMA alone (IC₅₀ = 52.5 µM) on MCF-7 breast cancer cells. In the future, NLCs containing IMA will possibly be employed to cure breast cancer. A small amount of IMA loaded into the NLCs will be better than IMA alone for the treatment of breast cancer. Moreover, patients will likely exhibit less adverse effects than in the case of IMA alone. Consequently, NANIMAs could prove to be useful for effective breast cancer treatment.

Multi-organ targeting of HIV-1 viral reservoirs with etravirine loaded nanostructured lipid carrier: An in-vivo proof of concept

The inadequate bioavailability and toxicity potential of antiretroviral therapy limit their effectiveness in the complete eradication of HIV from viral reservoirs. The penetration of these drugs into the brain is challenging because of the unfavorable physicochemical properties required to cross the membranes, limiting the transport of the drugs. Thus, in the current study, the authors report a nanocarrier-based drug delivery of a highly hydrophobic drug to overcome the existing limitations of the conventional therapies. An explicitly simple approach was used to overcome the limitations of existing anti-HIV therapies. The monophasic hot homogenized solution of lipid, drug, and solubilizer was diluted with the predetermined hot surfactant solution followed by the ultrasonication to generate the polydisperse nanoparticles with the size range of 50-1000 nm. The anti-HIV1 potential of nanostructured lipid carriers of Etravirine on HIV-infected cell lines showed efficacy with an appreciable increase in the therapeutic index as compared with the plain drug. Further, the results obtained from confocal microscopy along with flow cytometry exhibited efficient uptake of the nanocarrier loaded with coumarin-6 in cells. The pharmacokinetics of Etravirine nanostructured carriers was significantly better in all aspects compared to the plain drug solution, which could be attributed to molecular dispersion in the lipid matrix of the nanocarrier. A significant enhancement of Etravirine concentration of several-fold was also observed in the liver, ovary, lymph node, and brain, respectively, as compared to plain drug solution when assessed by biodistribution studies in rats. In conclusion, ETR-NLC systems could serve as a promising approach for simultaneous multi-site targeting and could provide therapeutic benefits for the efficient eradication of HIV/AIDS infections.

Recent updates in COVID-19 with emphasis on inhalation therapeutics: Nanostructured and targeting systems

The current world health threat posed by the novel coronavirus disease of 2019 (COVID-19) calls for the urgent development of effective therapeutic options. COVID-19 needs daunting routes such as nano-antivirals. Hence, the role of nanotechnology is very critical in combating this nano-enemy "virus." Although substantial resources are under ongoing attention for prevention and care, we would like to start sharing with readers our vision of the role of inhaled nanomaterials and targeting systems that can play an important role in the fight against the COVID-19. In this review, we underline the genomic structure of COVID-19, recent modes of virus transmission with measures to control the infection, pathogenesis, clinical presentation of SARS-CoV-2, and how much the virus affects the lung. Additionally, the recent therapeutic approaches for managing COVID-19 with emphasis on the value of nanomaterial-based technical approaches are discussed in this review. This review also focuses on the safe and efficient delivery of useable targeted therapies using designed nanocarriers. Moreover, the effectiveness and availability of active targeting of certain specific receptors expressed on the coronavirus surfaces via tailored ligand nanoparticles are manipulated. It was also highlighted in this review the role of inhaled medicines including antivirals and repurposed drugs for fighting the associated lung disorders and efficiency of developed vaccines. Moreover, the inhalation delivery safety techniques were also highlighted.

Design of experiments (DoE) to develop and to optimize nanoparticles as drug delivery systems

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.

Intranasal artesunate-loaded nanostructured lipid carriers: A convenient alternative to parenteral formulations for the treatment of severe and cerebral malaria

Early treatment with parenteral antimalarials is key in preventing deaths and complications associated with severe and cerebral malaria. This can be challenging in 'hard-to-reach' areas in Africa where transit time to hospitals with facilities to administer drugs parenterally can be more than 6 h. Consequently, the World Health Organization has recommended the use of artesunate (ATS) suppositories for emergency treatment of patients, however, this treatment is only for children under 6 years. The intranasal route (INR) can provide a safe and effective alternative to parenteral and rectal routes for patients of all ages; thus, reducing delays to the initiation of treatment. Hence, we designed ATS-loaded nanostructured lipid carriers (NLCs) for intranasal administration. ATS-NLCs were formulated using varying concentrations of lipid matrices made up of solidified reverse micellar solutions (SRMS) comprising a 1:2 ratio of Phospholipon ® 90H and lipids (Softisan ® 154 or Compritol ®). ATS-NLCs were spherical, and the small sizes of ATS-NLCs obtained for some formulations (76.56 ± 1.04 nm) is an indication that ATS-NLCs can pass through the nasal mucosa and reach the brain or systemic circulation. Encapsulation efficiency of ATS in NLCs was ≥70% for all formulations. ATS-NLCs achieved up to 40% in vitro drug release in 1 h, while ex vivo permeation studies revealed that formulating ATS as NLCs enhanced permeation through pig nasal mucosa better than drug solution. Most importantly, the activity and reduction in parasitaemia [in mice infected with Plasmodium berghei ANKA in a murine cerebral malaria model] by ATS-NLCs administered through the INR (54.70%, 33.28%) was comparable to intramuscular administration (58.80%, 42.18%), respectively. Therefore, intranasal administration of NLCs of ATS has great potentials to serve as a satisfactory alternative to parenteral administration for the treatment of severe and cerebral malaria in both adults and children in remote areas of sub-Saharan Africa.

Sesame Oil-Based Nanostructured Lipid Carriers of Nicergoline, Intranasal Delivery System for Brain Targeting of Synergistic Cerebrovascular Protection

Nicergoline (NIC) is a semisynthetic ergot alkaloid derivative applied for treatment of dementia and other cerebrovascular disorders. The efficacy of sesame oil to slow and reverse the symptoms of neurodegenerative cognitive disorders has been proven. This work aimed to formulate and optimize sesame oil-based NIC-nanostructured lipid carriers (NIC–NLCs) for intranasal (IN) delivery with expected synergistic and augmented neuroprotective properties. The NIC–NLC were prepared using sesame oil as a liquid lipid. A three-level, three-factor Box–Behnken design was applied to statistically optimize the effect of sesame oil (%) of the total lipid, surfactant concentration, and sonication time on particle size, zeta potential, and entrapment efficacy as responses. Solid-state characterization, release profile, and ex vivo nasal permeation in comparison to NIC solution (NIC–SOL) was studied. In vivo bioavailability from optimized NIC–NLC and NIC–SOL following IN and IV administration was evaluated and compared. The optimized NIC–NLC formula showed an average particle size of 111.18 nm, zeta potential of −15.4 mV, 95.11% entrapment efficacy (%), and 4.6% loading capacity. The NIC–NLC formula showed a biphasic, extended-release profile (72% after 48 h). Permeation of the NIC–NLC formula showed a 2.3 enhancement ratio. Bioavailability studies showed a 1.67 and 4.57 fold increase in plasma and brain following IN administration. The results also indicated efficient direct nose-to-brain targeting properties with the brain-targeting efficiency (BTE%) and direct transport percentage (DTP%) of 187.3% and 56.6%, respectively, after IN administration. Thus, sesame oil-based NIC–NLC can be considered as a promising IN delivery system for direct and efficient brain targeting with improved bioavailability and expected augmented neuroprotective action for the treatment of dementia.

Olanzapine Mesoporous Nanostructured Lipid Carrier: Optimization, Characterization, In Vivo Assessment, and Physiologically Based Pharmacokinetic Modeling

A promising approach has been emerging to enhance dissolution of hydrophobicdrugsby encapsulation in mesoporous silica materials. Olanzapine is a practically insoluble antipsychotic drug which is subjected to excessive first pass effect and shows inadequate oral bioavailability. Therefore, mesoporous silica was used to improve bioavailability of olanzapine incorporated in nano-structured lipid carriers (NLCs). These systems were characterized for their particle size, polydispersity index (PDI), zeta potential, entrapment efficiency (EE) and differential scanning calorimetry (DSC) as well asits release profile. The optimized mesoporous NLC system displayed nano-spherical particles (120.56 nm), possessed high entrapment efficiency (88.46%) and the highest percentage of drug released after six hours (75.13%). The biological performance of the optimized system was assessed in comparison with the drug suspension in healthy albino rabbits. The optimized system showed significantly (P < 0.05) prolonged MRT (8.47 h), higher C_max (22.12± 0.40 ng/ml) and T_max (2.0 h) values compared to drug suspension. Physiologically based pharmacokinetic (PBPK) model was simulated and verified. All the predicted results were within 0.6 and 1-fold of the reported data. To set a conclusion, in vitro results as well as in vivo pharmacokinetic study and PBPK data showed an enhancement in bioavailability of the optimized NLCs system over the plain drug suspension. These results proved the potentiality of incorporating olanzapine in mesoporous NLC for a significant improvement in oral bioavailability of olanzapine.

Efficient Treatment of Experimental Cerebral Malaria by an Artemisone-SMEDDS System: Impact of Application Route and Dosing Frequency

Artemisone (ART) has been successfully tested in vitro and in animal models against several diseases. However, its poor aqueous solubility and limited chemical stability are serious challenges. We developed a self-microemulsifying drug delivery system (SMEDDS) that overcomes these limitations. Here, we demonstrate the efficacy of this formulation against experimental cerebral malaria in mice and the impact of its administration using different routes (gavage, intranasal delivery, and parenteral injections) and frequency on the efficacy of the treatment. The minimal effective daily oral dose was 20 mg/kg. We found that splitting a dose of 20 mg/kg ART given every 24 h, by administering two doses of 10 mg/kg each every 12 h, was highly effective and gave far superior results compared to 20 mg/kg once daily. We obtained the best results with nasal treatment; oral treatment was ranked second, and the least effective route of administration was intraperitoneal injection. A complete cure of experimental cerebral malaria could be achieved through choosing the optimal route of application, dose, and dosing interval. Altogether, the developed formulation combines easy manufacturing with high stability and could be a successful and very versatile carrier for the delivery of ART in the treatment of human severe malaria.

Gefitinib loaded nanostructured lipid carriers: characterization, evaluation and anti-human colon cancer activity in vitro

NLC containing Gefitinib (NANOGEF) was prepared using stearic acid, sesame oil and surfactants (sodium lauryl sulfate and tween 80). NANOGEFs were evaluated for particle size, polydispersity index (PdI), zeta potential, entrapment efficiency (EE), stability, release studies and cytotoxicity studies (MTT assay). The optimized NANOGEF exhibited particle size of 74.06 ± 9.73 d.nm, PdI of 0.339 ± 0.029 and EE of 99.76 ± 0.015%. The TEM study revealed spherical shape of NANOGEF formulations. The slow and sustained release behavior was exhibited by all NANOGEFs. The effects of surfactants were observed not only on particle size but also on zeta potential, entrapment efficiency, stability and release studies. The MTT assay revealed 4.5 times increase in cytotoxicity for optimized NANOGEF (IC₅₀ = 4.642 µM) when compared with Gefitinib alone (IC₅₀ = 20.88 µM in HCT-116 cells). Thus NANOGEF may be considered as a potential drug delivery system for the cure of colon cancer.

Polysorbate-80 surface modified nano-stearylamine BQCA conjugate for the management of Alzheimer's disease

Acetylcholinesterase (AChE) inhibitors such as donepezil, galantamine and rivastigmine are used for the management of dementia in Alzheimer's Disease (AD). These drugs elevate endogenous acetylcholine (ACh) levels at the M1 muscarinic receptor in the brain to achieve therapeutic benefits. However, their side effects, such as nausea, vomiting, dizziness, insomnia, loss of appetite, altered heart rate, etc., are related to non-specific peripheral activation of M2-M5 muscarinic subtypes. It is logical, therefore, to develop drugs that selectively activate brain M1 receptors. Unfortunately, the orthosteric site homology among the receptor subtypes does not permit this approach. An alternative approach is to use positive allosteric modulator (PAM) of M1 receptors like benzyl quinolone carboxylic acid (BQCA). PAMs although devoid of M1 agonist activity, however, when bound, enhance the binding affinity of orthosteric ligand, Ach. The current challenge with PAMS is their low brain half-life, permeability, and higher elimination rates. This study reports active targeting of brain M1 receptors using surface modified nano lipid-drug conjugates (LDC) of M1 PAM, BQCA, to treat AD. Polysorbate-80 (P-80) surface modified stearylamine (SA)-BQCA conjugated nanoparticles (BQCA-SA-P80-NPs) were prepared by conjugating BQCA to SA, followed by the formation of nanoparticles (NPs) using P-80 by solvent injection method. The BQCA-SA-P80-NPs are near-spherical with a particle size (PS) of 166.62 ± 1.24 nm and zeta potential (ZP) of 23.59 ± 0.37 mV. In the in vitro cytotoxicity (SH-SY5Y cells) and hemolysis assays, BQCA-SA-P80-NPs, show acceptable safety and compatibility. In mice, Alzheimer's model, BQCA-SA-P80-NPs significantly prevent STZ induced changes in memory, neuronal Aβ1-42, p-Tau, APP, NF-κB, and BACE levels and neuronal cell death, when compared to untreated disease control and naïve BQCA treated group. Further, BQCA-SA-P80-NPs significantly improve the therapeutic efficacy of AChE inhibitor, donepezil (DPZ), indicating its potentiating effects. In vivo biodistribution studies in mice show selective accumulation of BQCA-SA-P80-NPs in the brain, suggesting an improved brain bioavailability and reduced peripheral side effects of BQCA. The study results demonstrate that BQCA-SA-P80-NPs can improve brain bioavailability and therapeutic efficacy of BQCA in AD.

Artemether-Loaded Zein Nanoparticles: An Innovative Intravenous Dosage Form for the Management of Severe Malaria

Artemether, an artemisinin derivative, is used in the management of life-threatening severe malaria. This study aimed to develop an intravenous dosage form of artemether using nanotechnology. Artemether-loaded zein nanoparticles were prepared by modified antisolvent precipitation using sodium caseinate as a stabilizer. Subsequently, the physicochemical properties of the nanoparticles were characterized; the in vitro hemolytic property was examined with red blood cells, while the pharmacokinetic profile was evaluated in Sprague–Dawley rats after intravenous administration. The artemether-loaded zein nanoparticles were found to display good encapsulation efficiency, excellent physical stability and offer an in vitro extended-release property. Interestingly, encapsulation of artemether into zein nanoparticles substantially suppressed hemolysis, a common clinical phenomenon occurring after artemisinin-based antimalarial therapy. Upon intravenous administration, artemether-loaded zein nanoparticles extended the mean residence time of artemether by ~80% in comparison to the free artemether formulation (82.9 ± 15.2 versus 45.6 ± 16.4 min, p < 0.01), suggesting that the nanoparticles may prolong the therapeutic duration and reduce the dosing frequency in a clinical setting. In conclusion, intravenous delivery of artemether by artemether-loaded zein nanoparticles appears to be a promising therapeutic option for severe malaria.

Mucoadhesive nanostructured lipid carriers as a cannabidiol nasal delivery system for the treatment of neuropathic pain

The therapeutic potential of cannabidiol (CBD) has been explored to treat several pathologies, including those in which pain is prevalent. However, the oral bioavailability of CBD is low owing to its high lipophilicity and extensive first-pass metabolism. Considering the ability of the nasal route to prevent liver metabolism and increase brain bioavailability, we developed nanostructured lipid carriers (NLCs) for the nasal administration of CBD. We prepared particles with a positively charged surface, employing stearic acid, oleic acid, Span 20^Ⓡ, and cetylpyridinium chloride to obtain mucoadhesive formulations. Characterisation of the CBD-NLC dispersions showed uniform nano-sized particles with diameters smaller than 200 nm, and high drug encapsulation. The mucoadhesion of cationic particles has been related to interactions with negatively charged mucin. Next, we added in-situ gelling polymers to the CBD-NLC dispersion to obtain a CBD-NLC-gel. A thermo-reversible in-situ forming gel was prepared by the addition of Pluronics^Ⓡ. CBD-NLC-gel was characterised by its gelation temperature, rheological behaviour, and mucoadhesion. Both formulations, CBD-NLC and CBD-NLC-gel, showed high mucoadhesion, as assessed by the flow-through method and similar in vitro drug release profiles. The in vivo evaluation showed that CBD-NLC dispersion (without gel), administered intranasally, produced a more significant and lasting antinociceptive effect in animals with neuropathic pain than the oral or nasal administration of CBD solution. However, the nasal administration of CBD-NLC-gel did not lessen mechanical allodynia. These findings demonstrate that in-situ gelling hydrogels are not suitable vehicles for highly lipophilic drugs such as CBD, while cationic CBD-NLC dispersions are promising formulations for the nasal administration of CBD.

Nanostructured Lipid Carriers (NLCs): Nose-to-Brain Delivery and Theranostic Application

BACKGROUND

Nanostructured lipid carriers (NLCs) are in high demand in the existing pharmaceutical domain due to its high versatility. It is the newer generation of lipid nanoparticulate systems having a solid matrix and greater stability at room temperature.

OBJECTIVE

To review the evidence related to the current state of the art of the NLCs system and its drug delivery perspectives to the brain.

METHODS

Scientific data search, review of the current state of the art and drug delivery perspectives to the brain for NLCs were undertaken to assess the applicability of NLCs in the management of neurological disorders through an intranasal route of drug administration.

RESULTS

NLCs are designed to fulfill all the industrial needs like simple technology, low cost, scalability, and quantifications. Biodegradable and biocompatible lipids and surfactants used for NLCs have rendered them acceptable from regulatory perspectives as well. Apart from these, NLCs have unique properties of high drug payload, modulation of drug release profile, minimum drug expulsion during storage, and incorporation in various dosage forms like gel, creams, granules, pellets, powders for reconstitution and colloidal dispersion. Ease of surface- modification of NLCs enhances targeting efficiency and reduces systemic toxicity by providing site-specific delivery to the brain through the intranasal route of drug administration.

CONCLUSION

The present review encompasses the in-depth discussion over the current state of the art of NLCs, nose-to-brain drug delivery perspectives, and its theranostic application as useful tools for better management of various neurological disorders. Further, pharmacokinetic consideration and toxicity concern is also discussed specifically for the NLCs system exploited in nose-to-brain delivery.