Nose to brain delivery of Rotigotine loaded solid lipid nanoparticles: Quality by design based optimization and characterization

Rational development of fingolimod nano-embedded microparticles as nose-to-brain neuroprotective therapy for ischemic stroke

Ischemic stroke is one of the major diseases causing varying degrees of dysfunction and disability worldwide. The current management of ischemic stroke poses significant challenges due to short therapeutic windows and limited efficacy, highlighting the pressing need for novel neuroprotective treatment strategies. Previous studies have shown that fingolimod (FIN) is a promising neuroprotective drug. Here, we report the rational development of FIN nano-embedded nasal powders using full factorial design experiments, aiming to provide rapid neuroprotection after ischemic stroke. Flash nanoprecipitation was employed to produce FIN nanosuspensions with the aid of polyvinylpyrrolidone and cholesterol as stabilizers. The optimized nanosuspension (particle size = 134.0 ± 0.6 nm, PDI = 0.179 ± 0.021, physical stability = 72 ± 0 h, and encapsulation efficiency of FIN = 90.67 ± 0.08%) was subsequently spray-dried into a dry powder, which exhibited excellent redispersibility (RdI = 1.09 ± 0.04) and satisfactory drug deposition in the olfactory region using a customized 3D-printed nasal cast (45.4%) and an Alberta Idealized Nasal Inlet model (8.6%) at 15 L/min. The safety of the optimized FIN nano-embedded dry powder was confirmed in cytotoxicity studies with nasal (RPMI 2650 and Calu-3 cells) and brain related cells (SH-SY5Y and PC 12 cells), while the neuroprotective effects were demonstrated by observed behavioral improvements and reduced cerebral infarct size in a middle cerebral artery occlusion mouse stroke model. The neuroprotective effect was further evidenced by increased expression of anti-apoptotic protein BCL-2 and decreased expression of pro-apoptotic proteins CC3 and BAX in brain peri-infarct tissues. Our findings highlight the potential of nasal delivery of FIN nano-embedded dry powder as a rapid neuroprotective treatment strategy for acute ischemic stroke.

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.

PEGylated solid lipid nanoparticles for the intranasal delivery of combination antiretroviral therapy composed of Atazanavir and Elvitegravir to treat NeuroAIDS

Intranasal drug administration offers a promising strategy for delivering combination antiretroviral therapy (cART) directly to the central nervous system to treat NeuroAIDS, leveraging the nose-to-brain route to bypass the blood-brain barrier. However, challenges such as enzymatic degradation in the nasal mucosa, low permeability, and mucociliary clearance within the nasal cavity must first be addressed to make this route feasible. To overcome these barriers, this study developed solid lipid nanoparticles (SLNs) with varying PEGylation levels (0 %, 5 %, 10 %, and 15 % w/w of PEGylated lipid), co-encapsulated with Elvitegravir (EVG) and Atazanavir (ATZ) as an integrase and protease inhibitor, respectively. Pre-formulation studies confirmed the compatibility of the drugs with the excipients. Characterization showed that PEGylation reduces SLN size by approximately up to 12 % while maintaining monodispersity and a high encapsulation efficiency of over 99 % for both EVG and ATZ in their amorphous forms. Incubation of the formulations in artificial nasal mucus revealed that increased PEGylation consistently reduces nanoparticle aggregation and mean aggregate size, suggesting improved SLN stability in the mucus. Importantly, higher PEGylation levels significantly enhanced model drug permeability across the nasal mucus barrier by up to 10-fold. Lastly, cellular uptake studies using the RPMI 2650 nasal epithelial cell line indicated that PEGylation does not reduce nanoparticle uptake rates. These findings highlight the potential of PEGylated SLNs as an effective vehicle for enhancing the intranasal delivery of cART to treat NeuroAIDS. However, further in vivo studies are needed to confirm the brain targeting potential of this formulation.

Novel Nose-to-brain delivery of carbenoxolone via mucoadhesive solid lipid nanoparticles for Parkinson's symptoms management: In vitro and in vivo evaluation in a rotenone-induced rat model

Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by motor and non-motor symptoms, with limited effective treatment options. This study proposes a novel approach utilizing intranasal delivery of carbenoxolone (CBX) via chitosan-coated solid lipid nanoparticles (CS-coated SLNs) to manage PD symptoms by enhancing CBX delivery and brain targeting. Formulated CS-coated SLNs exhibited favorable quality attributes including particle size (164 ± 0.12 nm), surface charge (18 ± 0.89 mV), high entrapment efficiency (97.98 ± 0.98 %), and sustained drug release profile. In vivo evaluations in a rotenone-induced rat model of PD involved intranasal administration of CBX suspension and CBX-loaded CS-coated SLN (equivalent to 20 mg/kg/day) over four weeks. The CBX nano-formulation group showed significant improvements in motor function, coordination, and balance, as well as modulation of neurotransmitter levels, with increased dopamine and decreased α-synuclein levels compared to the control group. Moreover, the CBX nano-formulation exhibited superior efficacy in reducing neuroinflammation, oxidative stress, and apoptosis markers. Histological examination revealed restored neuronal architecture, suggesting potential neuroprotective effects. In conclusion, mucoadhesive chitosan-coated SLNs offer a promising nasal delivery system overcoming brain drug delivery obstacles facing CBX therapy in PD, paving the way to the development of novel treatments and improved quality of life for PD patients.

A Combinatorial Approach with Microneedle Pretreatment and Thermosensitive Gel Loaded with Rivastigmine Lipid Nanoparticle Formulation Enables Brain Delivery via the Trigeminal Nerve

Alzheimer's disease (AD) often leads to dementia, causing cognitive decline and increased care needs. Rivastigmine (RV) is a key AD treatment, but its brain delivery is limited by the blood-brain barrier (BBB). Aside from oral, olfactory, and intradermal injection (i.d.) routes, the application of polymeric microneedles via the trigeminal nerve on the facial skin as a pretreatment, followed by a solid lipid nanoparticle RV-loaded thermosensitive gel (PMN-SLN-RV-TG), is an alternative to deal with the problems. This study aims to determine the optimal formula for PMN-SLN-RV-TG application and assess its brain delivery ability compared to conventional routes. The optimum SLN-RV formula had a particle size <200 nm and sustained release for 72 h, which was selected for the SLN-RV-TG formulation. SLN-RV-TG was transformed into a gel at normal skin temperature (32-37 °C), with good physical properties and nontoxic behavior. The ideal PMN formula was able to penetrate the dermal layer as an alternative to i.d. administration. Ex vivo dermatokinetics showed significant improvement of PMN-SLN-RV-TG application (p < 0.05) compared to without PMN application. In vivo pharmacokinetic studies on rats also revealed that the PMN-SLN-RV-TG had superior pharmacokinetic parameters (Cmax, AUC, t1/2, and MRT) compared to other groups (p < 0.05). Radiolabeling SLN-RV with 99mTc showed good physical properties, with a radiochemical yield of >95%. In vivo distribution studies of PMN-SLN-RV-TG application exhibited a higher brain:blood ratio than i.v. administration after 5 h, as well as being safe for the brain due to a good histological profile. These results show that PMN-SLN-RV-TG application via the trigeminal nerve on the facial skin has strong potential delivery to the brain for AD treatment.

Nanotechnological approaches for efficient N2B delivery: from small-molecule drugs to biopharmaceuticals

Central nervous system diseases negatively affect patients and society. Providing successful noninvasive treatments for these diseases is challenging because of the presence of the blood-brain barrier. While protecting the brain's homeostasis, the barrier limits the passage of almost all large-molecule drugs and most small-molecule drugs. A noninvasive method, nose-to-brain delivery (N2B delivery) has been proposed to overcome this challenge. By exploiting the direct anatomical interaction between the nose and the brain, the drugs can reach the target, the brain. Moreover, the drugs can be encapsulated into various drug delivery systems to enhance physicochemical characteristics and targeting success. Many preclinical data show that this strategy can effectively deliver biopharmaceuticals to the brain. Therefore, this review focuses on N2B delivery while giving examples of different drug delivery systems suitable for the applications. In addition, we emphasize the importance of the effective delivery of monoclonal antibodies and RNA and stress the recent literature tackling this challenge. While giving examples of nanotechnological approaches for the effective delivery of small or large molecules from the current literature, we highlight the preclinical studies and their results to prove the strategies' success and limitations.

Nanocarriers for the treatment of glioblastoma multiforme: A succinct review of conventional and repositioned drugs in the last decade

Glioblastoma multiforme is a very combative and threatening type of cancer. The standard course of treatment involves excising the tumor surgically, then administering chemotherapy and radiation therapy. Because of the presence of the blood-brain barrier and the unique characteristics of the tumor microenvironment, chemotherapy is extremely difficult and has a high incidence of relapse. With their capacity to precisely target and transport therapeutic medications to the tumor while overcoming the challenges provided by invasive and infiltrative gliomas, nanocarriers offer a potentially beneficial treatment option for gliomas. Drug repositioning or, in other words, finding novel therapeutic uses for medications that have received approval for previous uses has also recently emerged to provide alternative treatments for many diseases, with glioblastoma being among them. In this article, our goal is to shed light on the pathogenesis of glioma and summarize the proposed treatment approaches in the last decade, highlighting how combining repositioned drugs and nanocarriers technology can reduce drug resistance and improve therapeutic efficacy in primary glioma.

Non-Invasive Techniques of Nose to Brain Delivery Using Nanoparticulate Carriers: Hopes and Hurdles

Intranasal drug delivery route has emerged as a promising non-invasive method of administering drugs directly to the brain, bypassing the blood-brain barrier (BBB) and blood-cerebrospinal fluid barriers (BCSF). BBB and BCSF prevent many therapeutic molecules from entering the brain. Intranasal drug delivery can transport drugs from the nasal mucosa to the brain, to treat a variety of Central nervous system (CNS) diseases. Intranasal drug delivery provides advantages over invasive drug delivery techniques such as intrathecal or intraparenchymal which can cause infection. Many strategies, including nanocarriers liposomes, solid-lipid NPs, nano-emulsion, nanostructured lipid carriers, dendrimers, exosomes, metal NPs, nano micelles, and quantum dots, are effective in nose-to-brain drug transport. However, the biggest obstacles to the nose-to-brain delivery of drugs include mucociliary clearance, poor drug retention, enzymatic degradation, poor permeability, bioavailability, and naso-mucosal toxicity. The current review aims to compile current approaches for drug delivery to the CNS via the nose, focusing on nanotherapeutics and nasal devices. Along with a brief overview of the related pathways or mechanisms, it also covers the advantages of nasal drug delivery as a potential method of drug administration. It also offers several possibilities to improve drug penetration across the nasal barrier. This article overviews various in-vitro, ex-vivo, and in-vivo techniques to assess drug transport from the nasal epithelium into the brain.

Design of experiment (DoE) of mucoadhesive valproic acid-loaded nanostructured lipid carriers (NLC) for potential nose-to-brain application

Epilepsy is a highly prevalent neurological disease and valproic acid (VPA) is used as a first-line chronic treatment. However, this drug has poor oral bioavailability, which requires the administration of high doses, resulting in adverse effects. Alternative routes of VPA administration have therefore been investigated, such as the nose-to-brain route, which allows the drug to be transported directly from the nasal cavity to the brain. Here, the use of nanostructured lipid carriers (NLC) to encapsulate drugs administered in the nasal cavity has proved advantageous. The aim of this work was to optimise a mucoadhesive formulation of VPA-loaded NLC for intranasal administration to improve the treatment of epilepsy. The Design of Experiment (DoE) was used to optimise the formulation, starting with component optimisation using Mixture Design (MD), followed by optimisation of the manufacturing process parameters using Central Composite Design (CCD). The optimised VPA-loaded NLC had a particle size of 76.1 ± 2.8 nm, a polydispersity index of 0.190 ± 0.027, a zeta potential of 28.1 ± 2.0 mV and an encapsulation efficiency of 85.4 ± 0.8%. The in vitro release study showed VPA release from the NLC of 50 % after 6 h and 100 % after 24 h. The in vitro biocompatibility experiments in various cell lines have shown that the optimised VPA-loaded NLC formulation is safe up to 75 µg/mL, in neuronal (SH-SY5Y), nasal (RPMI 2650) and hepatic (HepG2) cells. Finally, the interaction of the optimised VPA-loaded NLC formulation with nasal mucus was investigated and mucoadhesive properties were observed. The results of this study suggest that the use of intranasal VPA-loaded NLC may be a promising alternative to promote VPA targeting to the brain, thereby improving bioavailability and minimising adverse effects.

Enhancing Acute Migraine Treatment: Exploring Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for the Nose-to-Brain Route

Migraine has a high prevalence worldwide and is one of the main disabling neurological diseases in individuals under the age of 50. In general, treatment includes the use of oral analgesics or non-steroidal anti-inflammatory drugs (NSAIDs) for mild attacks, and, for moderate or severe attacks, triptans or 5-HT1B/1D receptor agonists. However, the administration of antimigraine drugs in conventional oral pharmaceutical dosage forms is a challenge, since many molecules have difficulty crossing the blood-brain barrier (BBB) to reach the brain, which leads to bioavailability problems. Efforts have been made to find alternative delivery systems and/or routes for antimigraine drugs. In vivo studies have shown that it is possible to administer drugs directly into the brain via the intranasal (IN) or the nose-to-brain route, thus avoiding the need for the molecules to cross the BBB. In this field, the use of lipid nanoparticles, in particular solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), has shown promising results, since they have several advantages for drugs administered via the IN route, including increased absorption and reduced enzymatic degradation, improving bioavailability. Furthermore, SLN and NLC are capable of co-encapsulating drugs, promoting their simultaneous delivery to the site of therapeutic action, which can be a promising approach for the acute migraine treatment. This review highlights the potential of using SLN and NLC to improve the treatment of acute migraine via the nose-to-brain route. First sections describe the pathophysiology and the currently available pharmacological treatment for acute migraine, followed by an outline of the mechanisms underlying the nose-to-brain route. Afterwards, the main features of SLN and NLC and the most recent in vivo studies investigating the use of these nanoparticles for the treatment of acute migraine are presented.

Nanocarrier Mediated Intranasal Drug Delivery Systems for the Management of Parkinsonism: A Review

The transport of drugs to the brain becomes a key concern when treating disorders of the central nervous system. Parkinsonism is one of the major concerns across the world populations, which causes difficulty in coordination and balance. However, the blood-brain barrier is a significant barrier to achieving optimal brain concentration through oral, transdermal, and intravenous routes of administration. The intranasal route with nanocarrier-based formulations has shown potential for managing Parkinsonism disorder (PD). Direct delivery to the brain through the intranasal route is possible via the olfactory and trigeminal pathways using drug-loaded nanotechnology-based drug delivery systems. The critical analysis of reported works demonstrates dose reduction, brain targeting, safety, effectiveness, and stability for drug-loaded nanocarriers. The important aspects of intranasal drug delivery, PD details, and nanocarrier-based intranasal formulations in PD management with a discussion of physicochemical characteristics, cell line studies, and animal studies are the major topics in this review. Patent reports and clinical investigations are summarized in the last sections.

Design of experiment (DoE) as a quality by design (QbD) tool to optimise formulations of lipid nanoparticles for nose-to-brain drug delivery

INTRODUCTION

The nose-to-brain route has been widely investigated to improve drug targeting to the central nervous system (CNS), where lipid nanoparticles (solid lipid nanoparticles - SLN and nanostructured lipid carriers - NLC) seem promising, although they should meet specific criteria of particle size (PS) <200 nm, polydispersity index (PDI) <0.3, zeta potential (ZP) ~|20| mV and encapsulation efficiency (EE) >80%. To optimize SLN and NLC formulations, design of experiment (DoE) has been recommended as a quality by design (QbD) tool.

AREAS COVERED

This review presents recently published work on the optimization of SLN and NLC formulations for nose-to-brain drug delivery. The impact of different factors (or independent variables) on responses (or dependent variables) is critically analyzed.

EXPERT OPINION

Different DoEs have been used to optimize SLN and NLC formulations for nose-brain drug delivery, and the independent variables lipid and surfactant concentration and sonication time had the greatest impact on the dependent variables PS, EE, and PDI. Exploring different DoE approaches is important to gain a deeper understanding of the factors that affect successful optimization of SLN and NLC and to facilitate future work improving machine learning techniques.

Formulation of intranasal surface engineered nanostructured lipid carriers of rotigotine: Full factorial design optimization, in vitro characterization, and pharmacokinetic evaluation

The objective of the present research was to develop, optimize, and evaluate rotigotine (RT)-loaded chitosan (CH) coated nanostructured lipid carriers (RT-CH-NLCs) for nose-to-brain delivery. The NLCs were prepared by homogenization and sonication technique as well as optimized by using three factors at three-level Box-Behnken design. The prepared NLCs were evaluated for particle size, zeta potential, entrapment efficiency, drug release, and ex vivo permeation. The pharmacokinetic study was conducted on albino Wistar rats to evaluate the bioavailability and neuropharmacokinetic parameters after intranasal administration of the optimized formulation (RT-CH-NLCs-OPT). The optimized formulation showed the particle size (170.48 ± 8.37 nm), PDI (0.19 ± 0.03), zeta potential (+ 26.73 mV), and entrapment efficiency (82.37 ± 2.48 %). In vitro drug release study displayed a sustained drug release pattern from RT-CH-NLCs-OPT (86.73±8.58 % in 24 h) in comparison to RT-Dis (98.61±7.24 % in 16 h). The permeability coefficient (PC) was found to be 11.39 ± 1.08×10^-4 cm.h^-1 and 2.34 folds higher than RT-Dis (4.85±1.53×10^-4 cm.h^-1). The relative bioavailability of RT from RT-CH-NLCs-OPT was 3.2-fold greater as compared to RT-Dis. The absolute bioavailability of RT after intranasal administration of RT-CH-NLCs-OPT was 2.1-fold higher than RT-CH-NLCs-OPT administered intravenously. The brain targeting and targeting potential was displayed by DTE (422.03 %) and DTP (76.03 %) after intranasal administration of RT-CH-NLCs-OPT as compared to RT-Dis (DTE 173.91 % and DTP 59.97 %). Furthermore, confocal laser scanning microscopy results confirmed better brain targeting for RT-CH-NLCs-OPT as compared to RT-Dis. From these findings, it could be concluded that RT-CH-NLCs could serve as a promising strategy for targeting RT through the intranasal route.

New Drug Delivery Systems Developed for Brain Targeting

The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B_CSF) are two of the most complex and sophisticated concierges that defend the central nervous system (CNS) by numerous mechanisms. While they maintain the neuro-ecological homeostasis through the regulated entry of essential biomolecules, their conservative nature challenges the entry of most of the drugs intended for CNS delivery. Targeted delivery challenges for a diverse spectrum of therapeutic agents/drugs (non-small molecules, small molecules, gene-based therapeutics, protein and peptides, antibodies) are diverse and demand specialized delivery and disease-targeting strategies. This review aims to capture the trends that have shaped the current brain targeting research scenario. This review discusses the physiological, neuropharmacological, and etiological factors that participate in the transportation of various drug delivery cargoes across the BBB/B_CSF and influence their therapeutic intracranial concentrations. Recent research works spanning various invasive, minimally invasive, and non-invasive brain- targeting approaches are discussed. While the pre-clinical outcomes from many of these approaches seem promising, further research is warranted to overcome the translational glitches that prevent their clinical use. Non-invasive approaches like intranasal administration, P-glycoprotein (P-gp) inhibition, pro-drugs, and carrier/targeted nanocarrier-aided delivery systems (alone or often in combination) hold positive clinical prospects for brain targeting if explored further in the right direction.

The importance of pre-formulation studies and of 3D-printed nasal casts in the success of a pharmaceutical product intended for nose-to-brain delivery

This review aims to cement three hot topics in drug delivery: (a) the pre-formulation of new products intended for nose-to-brain delivery; (b) the development of nasal casts for studying the efficacy of potential new nose-to-brain delivery systems at the early of their development (pre-formulation); (c) the use of 3D printing based on a wide variety of materials (transparent, biocompatible, flexible) providing an unprecedented fabrication tool towards personalized medicine by printing nasal cast on-demand based on CT scans of patients. This review intends to show the links between these three subjects. Indeed, the pathway selected to administrate the drug to the brain not only influence the formulation strategies to implement but also the design of the cast, to get the most convincing measures from it. Moreover, the design of the cast himself influences the choice of the 3D-printing technology, which, in its turn, bring more constraints to the nasal replica design. Consequently, the formulation of the drug, the cast preparation and its realisation should be thought of as a whole and not separately.