Solid lipid nanoparticles (SLN) for controlled drug delivery. II. Drug incorporation and physicochemical characterization

Co-Delivery of siRNA and Docetaxel to Cancer Cells by NLC for Therapy

The present study aims to develop a delivery system that can carry small interference RNA (siRNA) with small-molecule chemotherapeutic drugs, which can be used in cancer treatment. The drug delivery system combines the advantages of a therapeutic agent with two different mechanisms to ensure that it is used efficiently for cancer therapy. In this study, a nanostructured lipid carrier system was prepared, Docetaxel was loaded to these systems, and the Eph siRNA was adsorbed to the outer surface. In addition, DOTAP was added to the lipophilic phase to load a positive charge on the lipidic structure for interaction with the cells. Moreover, characterization, cytotoxicity, and transfection procedures were performed on the whole system. This candidate system was also compared to Taxotere, which is the first approved Docetaxel-containing drug on the market. Given the results, it was determined that the particle size of NLC-DTX was 165.3 ± 3.5 nm, the ζ potential value was 38.2 ± 1.7 mV, and the PDI was 0.187 ± 0.024. Entrapment efficacy of nanoparticles was found to be 92.89 ± 0.21%. It was determined that the lipidic system prepared in vitro release analyses were able to provide sustained release and exhibit cytotoxicity, even at doses lower than the dose used for Taxotere. The formulations prepared had a higher level of effect on cells when compared with pure DTX and Taxotere, but they also exhibited time-dependent cytotoxicity. It was also observed that the use of Eph siRNA together with the chemotherapeutic agent via formulation also contributed to this cell death. The results of the present study indicate that there is a promising carrier system in order to deliver hydrophilic nucleic acids, such as siRNA, together with lipophilic drugs in cancer treatment.

Nanoencapsulation of general anaesthetics

General anaesthetics are routinely used to sedate patients during prolonged surgeries and administered via intravenous injection and/or inhalation. All anaesthetics have short half-lives, hence the need for their continuous administration. This causes several side effects such as pain, vomiting, nausea, bradycardia, and on rare occasions death post-administration. Several clinical trials studied the synergetic effect of a combination of anaesthetic drugs to reduce the drug load. Another solution is to encapsulate anaesthetics in nanoparticles to reduce their dose and side effects as well as achieve their sustained release manner. Different types of nanoparticles were developed as carriers of intravenous and intrathecal anaesthetics generating platforms which facilitate drug transport across the blood-brain barrier (BBB). Nanocarriers encapsulating common anaesthetic drugs such as propofol, etomidate, and ketamine were developed and characterized in terms of size, stability, onset and duration of loss of right reflex, and tolerance to pain in small animal models. The review discusses the types of nanocarriers used to reduce the side effects of the anaesthetic drugs while prolonging the sedation time. More rigorous studies are still required to evaluate the nanocarrier formulations regarding their ability to deliver anaesthetic drugs across the BBB, safety, and finally applicability in clinical settings.

Nanotechnology-Based Strategies in Parasitic Disease Management: From Prevention to Diagnosis and Treatment

Parasitic infections are a major global health issue causing significant mortality and morbidity. Despite substantial advances in the diagnostics and treatment of these diseases, the currently available options fall far short of expectations. From diagnosis and treatment to prevention and control, nanotechnology-based techniques show promise as an alternative approach. Nanoparticles can be designed with specific properties to target parasites and deliver antiparasitic medications and vaccines. Nanoparticles such as liposomes, nanosuspensions, polymer-based nanoparticles, and solid lipid nanoparticles have been shown to overcome limitations such as limited bioavailability, poor cellular permeability, nonspecific distribution, and rapid drug elimination from the body. These nanoparticles also serve as nanobiosensors for the early detection and treatment of these diseases. This review aims to summarize the potential applications of nanoparticles in the prevention, diagnosis, and treatment of parasitic diseases such as leishmaniasis, malaria, and trypanosomiasis. It also discusses the advantages and disadvantages of these applications and their market values and highlights the need for further research in this field.

Therapeutic potential of lipid nanosystems for the treatment of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The degeneration of dopaminergic neurons in the midbrain is primarily responsible for the onset of the disease. The major challenge faced in the treatment of PD is the blood-brain barrier (BBB), which impedes the delivery of therapeutics to targeted locations. To address this issue, lipid nanosystems have been used for the precise delivery of therapeutic compounds in anti-PD therapy. In this review, we will discuss the application and clinical significance of lipid nanosystem in delivering therapeutic compounds for anti-PD treatment. These medicinal compounds include ropinirole, apomorphine, bromocriptine, astaxanthin, resveratrol, dopamine, glyceryl monooleate, levodopa, N-3,4-bis(pivaloyloxy)- dopamine and fibroblast growth factor, which have significant potential to treat PD in the early stage. This review, in a nutshell, will pave the way for researchers to develop diagnostic and potential therapeutic approaches using nanomedicine to overcome the challenges posed by the BBB in delivering therapeutic compounds for PD.

Preparation, Characterization and Pharmacokinetics of Tolfenamic Acid-Loaded Solid Lipid Nanoparticles

The clinical use of nonsteroidal anti-inflammatory drugs is limited by their poor water solubility, unstable absorption, and low bioavailability. Solid lipid nanoparticles (SLNs) exhibit high biocompatibility and the ability to improve the bioavailability of drugs with low water solubility. Therefore, in this study, a tolfenamic acid solid lipid nanoparticle (TA-SLN) suspension was prepared by a hot melt–emulsification ultrasonication method to improve the sustained release and bioavailability of TA. The encapsulation efficiency (EE), loading capacity (LC), particle size, polydispersity index (PDI), and zeta potential of the TA-SLN suspension were 82.50 ± 0.63%, 25.13 ± 0.28%, 492 ± 6.51 nm, 0.309 ± 0.02 and −21.7 ± 0.51 mV, respectively. The TA-SLN suspension was characterized by dynamic light scattering (DLS), fluorescence microscopy (FM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared (FT-IR) spectroscopy. The TA-SLN suspension showed improved sustained drug release in vitro compared with the commercially available TA injection. After intramuscular administration to pigs (4 mg/kg), the TA-SLN suspension displayed increases in the pharmacokinetic parameters T_max, T_1/2, and MRT_0–∞ by 4.39-, 3.78-, and 3.78-fold, respectively, compared with TA injection, and showed a relative bioavailability of 185.33%. Thus, this prepared solid lipid nanosuspension is a promising new formulation.

Transferrin-Modified Mangiferin-Loaded SLNs: Preparation, Characterization, and Application in A549 Lung Cancer Cell

Introduction

Mangiferin is a plant antitumor compound with poor water solubility and low bioavailability. In this study, transferrin-modified mangiferin-loaded solid lipid nanoparticles (Tf-modified MGF-SLNs) were prepared to overcome the above defects.

Methods

Tf-modified MGF-SLNs were prepared by the emulsification-solvent evaporation method. The physicochemical properties of Tf-MGF-SLNs such as particle size, zeta potential and in vitro drug release were investigated. We also demonstrated the effect of Tf-MGF-SLNs in lung cancer.

Results

The mean hydrodynamic diameter of the Tf-MGF-SLNs was 121.8±2.9 nm with a polydispersity index of 0.134±0.03. According to TEM micrographs, Tf-MGF-SLNs are spherical and uniform, and the EE% was found to be 72.5±2.4%. In vitro release, we identified an initial burst effect release, followed by controlled release, in SLNs at both pHs and the Tf-MGF-SLNs drug accumulation release percentages reached over 68% at pH 4.0 and 72% at pH 7.4 in 6 hours, respectively. In vivo studies showed that depending on surface modification, Tf-MGF-SLNs, which suggested that cell internalization was changed and more drugs entered the cells successfully.

Discussion

Tf-MGF-SLNs were highly efficient in suppressing the tumor growth in xenograft tumor model. Sustained release of the drug delivery system and Tf-modified MGF-SLNs played a major role. Tf-MGF-SLNs would be a promising formulation for the treatment of lung cancer.

Formulation Design, Characterization and In-Vivo Assessment of Cefixime Loaded Binary Solid Lipid Nanoparticles to Enhance Oral Bioavailability

Cefixime; widely employed cephalosporin antibiotic is unfortunately coupled to poor water solubility with resultant low oral bioavailability issues. To solve this problem micro-emulsion technique was used to fabricate binary SLNs using blend of solid and liquid lipids, surfactant as well as co-surfactant. The optimized nano suspension was characterized followed by modification to solidified dosage form. During characterization, optimized nano-suspension (CFX-4) produced particle size 189±2.1 nm with PDI 0.310±0.02 as well as -33.9±2 mV zeta potential. Scanning electron microscopy (SEM) presented nearly identical and spherical shaped particles. Differential scanning calorimetry and X-ray powder diffraction analysis ascertained decrease in drug's crystallinity. In-vitro release of drug pursued zero-order characteristics and demonstrated non-fickian pattern of diffusion. The freeze dried nano suspension (CFX-4) was transformed to capsule dosage form to perform comparison based In-Vivo studies. In-Vivo evaluation corresponded to 2.20-fold and 2.11-fold enhancement in relative bioavailability of CFX nano-formulation (CFX-4) as well as the prepared capsules respectively in contrast to the commercialized product (Cefiget®). In general; the obtained results substantiated superior oral bioavailability along with sustained pattern of drug release for CFX loaded binary nano particles. Thus, binary SLNs could be employed as a resourceful drug carrier for oral CFX delivery.

Lipid-Based Nanocarriers via Nose-to-Brain Pathway for Central Nervous System Disorders

Neurodegenerative disorders are distinguished by the gradual deterioration of the nervous system's structure and function due to oxidative stress, mitochondrial dysfunction, protein misfolding, excitotoxicity, and neuroinflammation. Among these NDs, Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis characterized an increasing dysfunction and loss of neuronal structure leading to neuronal cell death. Although there is currently no drug to totally reverse the effects of NDs, such novel formulations and administration routes are developed for better management and nose-to-brain delivery is one of delivery for treating NDs. This review aimed to highlight advances in research on various lipid based nanocarriers such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion, nanoemulsion, and cubosomes which are reported to treat and alleviate the symptoms of NDs via nose-to-brain route. The challenges during clinical translation of lipid nanocarriers from bench to bed side is also discussed.

Synthesis and Potential Applications of Lipid Nanoparticles in Medicine

Currently, carriers of active ingredients in the form of particles of a size measured in nanometers are the focus of interest of research centers worldwide. So far, submicrometer emulsions, liposomes, as well as microspheres, and nanospheres made of biodegradable polymers have been used in medicine. Recent studies show particular interest in nanoparticles based on lipids, and at the present time, are even referred to as the "era of lipid carriers". With the passage of time, lipid nanoparticles of the so-called first and second generation, SLN (Solid Lipid Nanoparticles) and nanostructured lipid carriers and NLC (Nanostructured Lipid Carriers), respectively, turned out to be an alternative for all imperfections of earlier carriers. These carriers are characterized by a number of beneficial functional properties, including, among others, structure based on lipids well tolerated by the human body, high stability, and ability to carry hydro- and lipophilic compounds. Additionally, these carriers can enhance the distribution of the drug in the target organ and alter the pharmacokinetic properties of the drug carriers to enhance the medical effect and minimize adverse side effects. This work is focused on the current review of the state-of-the-art related to the synthesis and applications of popular nanoparticles in medicine, with a focus on their use, e.g., in COVID-19 vaccines.

Breaking the barriers for the delivery of amikacin: Challenges, strategies, and opportunities

Hypodermic delivery of amikacin is a widely adopted treatment modality for severe infections, including bacterial septicemia, meningitis, intra-abdominal infections, burns, postoperative complications, and urinary tract infections in both paediatric and adult populations. In most instances, the course of treatment requires repeated bolus doses of amikacin, prolonged hospitalization, and the presence of a skilled healthcare worker for administration and continuous therapeutic monitoring to manage the severe adverse effects. Amikacin is hydrophilic and exhibits a short half-life, which further challenges the delivery of sufficient systemic concentrations when administered by the oral or transdermal route. In this purview, the exploitation of novel controlled and sustained release drug delivery platforms is warranted. Furthermore, it has been shown that novel delivery systems are capable of increasing the antibacterial activity of amikacin at lower doses when compared to the conventional formulations and also aid in overcoming the development of drug-resistance, which currently is a significant threat to the healthcare system worldwide. The current review presents a comprehensive overview of the developmental history of amikacin, the mechanism of action in virulent strains as well as the occurrence of resistance, and various emerging drug delivery solutions developed both by the academia and the industry. The examples outlined within the review provides significant pieces of evidence on novel amikacin formulations in the field of antimicrobial research paving the path for future therapeutic interventions that will result in improved clinical outcome.

Solid Lipid Nanoparticles (SLNs): An Advanced Drug Delivery System Targeting Brain through BBB

The blood-brain barrier (BBB) plays a vital role in the protection and maintenance of homeostasis in the brain. In this way, it is an interesting target as an interface for various types of drug delivery, specifically in the context of the treatment of several neuropathological conditions where the therapeutic agents cannot cross the BBB. Drug toxicity and on-target specificity are among some of the limitations associated with current neurotherapeutics. In recent years, advances in nanodrug delivery have enabled the carrier system containing the active therapeutic drug to target the signaling pathways and pathophysiology that are closely linked to central nervous system (CNS) disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS), brain tumor, epilepsy, ischemic stroke, and neurodegeneration. At present, among the nano formulations, solid lipid nanoparticles (SLNs) have emerged as a putative drug carrier system that can deliver the active therapeutics (drug-loaded SLNs) across the BBB at the target site of the brain, offering a novel approach with controlled drug delivery, longer circulation time, target specificity, and higher efficacy, and more importantly, reducing toxicity in a biomimetic way. This paper highlights the synthesis and application of SLNs as a novel nontoxic formulation strategy to carry CNS drugs across the BBB to improve the use of therapeutics agents in treating major neurological disorders in future clinics.

Nano Based Approach for the Treatment of Neglected Tropical Diseases

Neglected tropical diseases (NTDs) afflict more than one billion peoples in the world’s poorest countries. The World Health Organization (WHO) has recorded seventeen NTDs in its portfolio, mainly caused by bacterial, protozoal, parasitic, and viral infections. Each of the NTDs has its unique challenges on human health such as interventions for control, prevention, diagnosis, and treatment. Research for the development of new drug molecules against NTDs has not been undertaken by pharmaceutical industries due to high investment and low-returns, which results in limited chemotherapeutics in the market. In addition, conventional chemotherapies for the treatment of NTDs are unsatisfactory due to its low efficacy, increased drug resistance, short half-life, potential or harmful fatal toxic side effects, and drug incompetence to reach the site of parasite infection. In this context, active chemotherapies are considered to be re-formulated by overcoming these toxic side effects via a tissue-specific targeted drug delivery system. This review mainly emphasizes the recent developments of nanomaterial-based drug delivery systems for the effective treatment of NTDs especially sleeping sickness, leishmaniasis, chagas disease, soil-transmitted helminthiasis, african trypanosomiasis and dengue. Nanomaterials based drug delivery systems offer enhanced and effective alternative therapy through the re-formulation approach of conventional drugs into site-specific targeted delivery of drugs.

Downregulation of MMP1 expression mediates the anti-aging activity of Citrus sinensis peel extract nanoformulation in UV induced photoaging in mice

Aging of the skin is a complicated bioprocess that is affected by constant exposure to ultraviolet irradiation. The application of herbal-based anti-aging creams is still the best choice for treatment. In the present study, Citrus sinensis L. fruit peels ethanolic extract (CSPE) was formulated into lipid nanoparticles (LNPs) anti-aging cream. Eight different formulations of CSEP-LNPs were prepared and optimized using 2³ full factorial designs. In vivo antiaging effect of the best formula was tested in Swiss albino mice where photo-aging was induced by exposure to UV radiation. HPLC-QToF-MS/MS metabolic profiling of CSPE led to the identification of twenty-nine metabolites. CSPE was standardized to a hesperidin content of 15.53 ± 0.152 mg% using RP-HPLC. It was suggested that the optimized formulation (F7) had (245 nm) particle size, (91.065%) EE, and (91.385%) occlusive effect with a spherical and smooth surface. The visible appearance of UV-induced photoaging in mice was significantly improved after topical application on CSPE-NLC cream for 5 weeks, levels of collagen and SOD were significantly increased in CSPE- NLC group, while levels of PGE2, COX2, JNK, MDA, and elastin was reduced. Finally, The prepared anti-aging CSPE-NLC cream represents a safe, convenient, and promising skincare cosmetic product.

Lipid-based nano-formulation platform for eplerenone oral delivery as a potential treatment of chronic central serous chorioretinopathy: in-vitro optimization and ex-vivo assessment

Purpose

Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist used for treatment of chronic central serous chorioretinopathy which characterized by accumulation of subretinal fluid causing a localized area of retinal detachment. unfortunately, EPL suffers from poor oral bioavailability due to poor aqueous solubility in addition to high hepatic first pass metabolism.

Method

Aiming to improve its oral bioavailability, EPL-loaded nanostructured lipid carriers (NLCs) were prepared by the emulsification solvent evaporation method and in-vitro evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). A D-optimal design was used for study the effect of liquid lipid to solid lipid ratio, surfactant type and percentage on PS, PDI, EE%, and for data optimization. The optimized EPL-loaded NLCs system was further evaluated using in-vitro drug release and ex-vivo permeation studies through rabbit intestine in comparison to EPL aqueous suspension. The physicochemical properties of the drug in the optimized system were further examined using FT-IR and X-ray diffraction studies.

Results

The resultant NLCs showed small PS (100.85–346.60 nm), homogenous distribution (0.173–0.624), negatively charged particles (ZP −20.20 to −36.75 mV), in addition to EE% (34.31–70.64%). The optimized EPL-loaded NLCs system with a desirability value of 0.905 was suggested through the Design expert^® software, containing liquid to solid lipid ratio (2:1) in presence of 0.43%w/v Pluronic^® F127 as a surfactant. The optimized EPL-loaded NLCs system showed a PS of 134 nm and PDI of 0.31, in addition to high EE% (76 ± 6.56%w/w), and ZP (-32.37 mV). The ex-vivo permeation study showed two-fold higher drug permeation through rabbit intestine compared to that from the aqueous drug suspension after 24 h, confirming the ability of optimized EPL-loaded NLCs system as successful oral targeting delivery carrier.

Conclusion

Our results pave the way for a new oral nanotherapeutic approach toward CSCR treatment. In-vivo study is currently under investigation.

Preparation, Statistical Optimization and In-vitro Characterization of a Dry Powder Inhaler (DPI) Containing Solid Lipid Nanoparticles Encapsulating Amphotericin B: Ion Paired Complexes with Distearoyl Phosphatidylglycerol

The aim of this study was to prepare dry powder inhalers (DPIs) containing amphotericin B-loaded solid lipid nanoparticles (AMB-SLNs) as an alternative approach for prevention of pulmonary aspergillosis. For solubilizing AMB in small amounts of organic solvents ion paired complexes were firstly formed by establishing electrostatic interaction between AMB and distearoyl phosphatidylglycerol (DSPG). The SLN formulations containing AMB-DSPG complexes were prepared using glycerol monostearate (GMS) as the lipid matrix and soybean lecithin and tween 80 as the surfactants by solvent emulsification-evaporation technique. The nanoparticles were optimized through a fractional factorial design. DPIs were prepared by lyophilization technique using lactose as the inhalational carrier and then after, the formulations were evaluated in terms of aerodynamic particle size distribution using an Andersen cascade impactor. The morphology of the particles was examined using scanning electron microscopy (SEM) and in-vitro drug release profiles were evaluated. Following the statistical results, the particle size, Poly dispersity index (PdI), zeta potential, entrapment efficiency (EE%), and drug loading (DL%) of the optimized SLNs were 187.04 ± 11.97 nm, 0.188 ± 0.028, -30.16 ± 1.6 mV, 89.3 ± 3.47 % and 2.76 ± 0.32 %, respectively. Formulation containing 10% w/v of lactose with the calculated fine particle fraction value as 72.57 ± 4.33% exhibited the appropriate aerodynamic characteristics for pulmonary drug delivery. SEM images revealed de-agglomerated particles. In-vitro release studies showed sustained release of AMB from the carriers and the release kinetics were best fitted to the first order kinetic model.

Drug localization and its effect on the physical stability of poloxamer 188-stabilized colloidal lipid emulsions

Colloidal lipid emulsions are a promising formulation option for poorly water-soluble drugs. Due to their complex composition, they provide different sites for the localization of drugs. Drug molecules can be situated in the lipid matrix, in the aqueous phase with its structures formed by an excess of emulsifier or at the droplet interface. The interface and the mechanism of stabilization is mainly characterized by the emulsifier. In this study, the main focus was on the influence of drug localization on the stability of emulsions sterically stabilized with poloxamer188. In addition to 5% of this non-ionic emulsifier, the emulsions contained 10% soybean oil. The localization of the drugs fenofibrate, curcumin, betamethasone valerate, cinnarizine, dibucaine and flufenamic acid within the emulsion system at a physiological pH of 7.4 as well as their influence on emulsion stability were examined. The results indicated that the stability of poloxamer 188-stabilized emulsions can be influenced in a positive or negative way by the localization of drug molecules in the interface of emulsion droplets. Applying cinnarizine as model substance at pH 5, 7.4 and 10, no pronounced change in the localization was detected as a result of alterations in the charge of the drug.

Design, Synthesis, Anticancer Activity, and Solid Lipid Nanoparticle Formulation of Indole- and Benzimidazole-Based Compounds as Pro-Apoptotic Agents Targeting Bcl-2 Protein

Cancer is a multifactorial disease necessitating identification of novel targets for its treatment. Inhibition of Bcl-2 for triggered pro-apoptotic signaling is considered a promising strategy for cancer treatment. Within the current work, we aimed to design and synthesize a new series of benzimidazole- and indole-based derivatives as inhibitors of Bcl-2 protein. The market pan-Bcl-2 inhibitor, obatoclax, was the lead framework compound for adopted structural modifications. The obatoclax’s pyrrolylmethine linker was replaced with straight alkylamine or carboxyhydrazine methylene linkers providing the new compounds. This strategy permitted improved structural flexibility of synthesized compounds adopting favored maneuvers for better fitting at the Bcl-2 major hydrophobic pocket. Anti-cancer activity of the synthesized compounds was further investigated through MTT-cytotoxic assay, cell cycle analysis, RT-PCR, ELISA and DNA fragmentation. Cytotoxic results showed compounds 8a, 8b and 8c with promising cytotoxicity against MDA-MB-231/breast cancer cells (IC₅₀ = 12.69 ± 0.84 to 12.83 ± 3.50 µM), while 8a and 8c depicted noticeable activities against A549/lung adenocarcinoma cells (IC₅₀ = 23.05 ± 1.45 and 11.63 ± 2.57 µM, respectively). The signaling Bcl-2 inhibition pathway was confirmed by molecular docking where significant docking energies and interactions with key Bcl-2 pocket residues were depicted. Moreover, the top active compound, 8b, showed significant upregulated expression levels of pro-apoptotic/anti-apoptotic of genes; Bax, Bcl-2, caspase-3, -8, and -9 through RT-PCR assay. Improving the compound’s pharmaceutical profile was undertaken by introducing 8b within drug-solid/lipid nanoparticle formulation prepared by hot melting homogenization technique and evaluated for encapsulation efficiency, particle size, and zeta potential. Significant improvement was seen at the compound’s cytotoxic activity. In conclusion, 8b is introduced as a promising anti-cancer lead candidate that worth future fine-tuned lead optimization and development studies while exploring its potentiality through in-vivo preclinical investigation.

Development of Pomegranate Extract-Loaded Solid Lipid Nanoparticles: Quality by Design Approach to Screen the Variables Affecting the Quality Attributes and Characterization

The aim of this work was to study the influence of process variables on the quality attributes of pomegranate extract loaded solid lipid nanoparticles (PE-SLNs) using Plackett-Burman design. PE-SLN formulations were prepared by hot homogenization followed by ultra-sonication technique and evaluated based on the dependent variables that were analyzed utilizing Statgraphics Centurion XV software. The lipid and surfactant (type and concentration), co-surfactant concentration, sonication time, and amplitude were selected as the independent variables (X ₁-X ₇). The dependent parameters were particle size, polydispersity index, zeta potential, entrapment efficiency, and cumulative drug release (Y ₁-Y ₅). Response surface plots, Pareto charts, and mathematical equations were generated to study the influence of independent variables on the dependent quality parameters. Out of seven variables, X ₁, X ₂, and X ₆ have the main significant (p value < 0.05) effect on the entrapment efficiency, the cumulative drug release, the polydispersity index, respectively, while particle size was mainly affected by X ₃, X ₆ and zeta potential by X ₁, X ₃, and X ₄. Consequently, this screening study revealed that stearic acid as lipid, Tween 80 as surfactant, as well as sonication with short time and high amplitude can be selected for the development of PE-SLN formulation with minimum particle size, maximum zeta potential, highest entrapment, and sustained drug release behavior. Meanwhile, concentrations of lipid, surfactant, and co-surfactant are planned to be scaled up for further optimization study. In conclusion, the Plackett-Burman design verified its influence and significance in determining and understanding both process and formulation variables affecting the quality of PE-SLNs.

A brief review on solid lipid nanoparticles: part and parcel of contemporary drug delivery systems

Drug delivery technology has a wide spectrum, which is continuously being upgraded at a stupendous speed. Different fabricated nanoparticles and drugs possessing low solubility and poor pharmacokinetic profiles are the two major substances extensively delivered to target sites. Among the colloidal carriers, nanolipid dispersions (liposomes, deformable liposomes, virosomes, ethosomes, and solid lipid nanoparticles) are ideal delivery systems with the advantages of biodegradation and nontoxicity. Among them, nano-structured lipid carriers and solid lipid nanoparticles (SLNs) are dominant, which can be modified to exhibit various advantages, compared to liposomes and polymeric nanoparticles. Nano-structured lipid carriers and SLNs are non-biotoxic since they are biodegradable. Besides, they are highly stable. Their (nano-structured lipid carriers and SLNs) morphology, structural characteristics, ingredients used for preparation, techniques for their production, and characterization using various methods are discussed in this review. Also, although nano-structured lipid carriers and SLNs are based on lipids and surfactants, the effect of these two matrixes to build excipients is also discussed together with their pharmacological significance with novel theranostic approaches, stability and storage.

Preparation and evaluation of inhalable dry powder containing glucosamine-conjugated gefitinib SLNs for lung cancer therapy

Gefitinib as an epidermal growth factor receptor tyrosine kinase inhibitor has strong potential in lung cancer therapy. However, a major challenge of using gefitinib is its toxicities. In the present study, we developed a dry powder inhaler dosage form containing gefitinib loaded glucosamine targeted solid lipid nanopaticles (Gef-G-SLNs) to locally transfer anticancer agent to the lung tumor. The Gef-G-SLNs were prepared by emulsion-solvent diffusion and evaporation method and optimized with irregular factorial design. The optimized nanoformulation was tested for action against A549 cells. Mannitol or lactose based dry powders were obtained from Gef-G-SLNs after spray drying and characterized using Anderson Cascade Impactor. The optimized formulation had drug loading of 33.29%, encapsulation efficiency of 97.31 ± 0.23%, zeta potential of -15.53 ± 0.47 mV, particle size of 187.23 ± 14.08 nm, polydispersity index of 0.28 ± 0.02 and release efficiency of 35.46 ± 2.25%. The Gef-G-SLNs showed superior anticancer effect compared to free gefitinib. The increased cellular uptake of G-SLNs in A549 cells was demonstrated compared with non-targeted SLNs using flow cytometry and fluorescence microscopy. The produced mannitol based microparticles showed suitable aerodynamic properties with an acceptable mass median aerodynamic diameter of 4.48 µm and fine particle fraction of 44.41%. Therefore, it can be concluded that this formulation represents promising drug delivery to treatment of lung cancer.

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

Docetaxel-loaded solid lipid nanoparticles prevent tumor growth and lung metastasis of 4T1 murine mammary carcinoma cells

BACKGROUND

Metastasis causes the most breast cancer-related deaths in women. Here, we investigated the antitumor effect of solid lipid nanoparticles (SLN-DTX) when used in the treatment of metastatic breast tumors using 4T1-bearing BALB/c mice.

RESULTS

Solid lipid nanoparticles (SLNs) were produced using the high-energy method. Compritol 888 ATO was selected as the lipid matrix, and Pluronic F127 and Span 80 as the surfactants to stabilize nanoparticle dispersion. The particles had high stability for at least 120 days. The SLNs' dispersion size was 128 nm, their polydispersity index (PDI) was 0.2, and they showed a negative zeta potential. SLNs had high docetaxel (DTX) entrapment efficiency (86%), 2% of drug loading and showed a controlled drug-release profile. The half-maximal inhibitory concentration (IC₅₀) of SLN-DTX against 4T1 cells was more than 100 times lower than that of free DTX after 24 h treatment. In the cellular uptake test, SLN-DTX was taken into the cells significantly more than free DTX. The accumulation in the G2-M phase was significantly higher in cells treated with SLN-DTX (73.7%) than in cells treated with free DTX (23.0%), which induced subsequent apoptosis. TEM analysis revealed that SLN-DTX internalization is mediated by endocytosis, and fluorescence microscopy showed DTX induced microtubule damage. In vivo studies showed that SLN-DTX compared to free docetaxel exhibited higher antitumor efficacy by reducing tumor volume (p < 0.0001) and also prevented spontaneous lung metastasis in 4T1 tumor-bearing mice. Histological studies of lungs confirmed that treatment with SLN-DTX was able to prevent tumor. IL-6 serum levels, ki-67 and BCL-2 expression were analyzed and showed a remarkably strong reduction when used in a combined treatment.

CONCLUSIONS

These results indicate that DTX-loaded SLNs may be a promising carrier to treat breast cancer and in metastasis prevention.

Improving the Oral Bioavailability of an Anti-Glioma Prodrug CAT3 Using Novel Solid Lipid Nanoparticles Containing Oleic Acid-CAT3 Conjugates

13a-(S)-3-pivaloyloxyl-6,7-dimethoxyphenanthro(9,10-b)-indolizidine (CAT3) is a novel oral anti-glioma pro-drug with a potent anti-tumor effect against temozolomide-resistant glioma in vivo. However, poor lipid solubility has limited the encapsulation efficacy during formulation development. Moreover, although the active metabolite of CAT3, 13a(S)-3-hydroxyl-6,7-dimethoxyphenanthro(9,10-b)-indolizidine (PF403), can penetrate the blood-brain barrier and approach the brain tissue with a 1000-fold higher anti-glioma activity than CAT3 in vitro, its bioavailability and Cmax were considerably low in plasma, limiting the anti-tumor efficacy. In this study, a novel oleic acid-CAT3 conjugate (OA-CAT3) was synthesized at the first time to increase the lipid solubility of CAT3. The OA-CAT3 loaded solid lipid nanoparticles (OA-CAT3-SLN) were constructed using an ultrasonic technique to enhance the bioavailability and Cmax of PF403 in plasma. Our results demonstrated that CAT3 was amorphous in the lipid core of OA-CAT3-SLN and the in vitro release was well controlled. Furthermore, the encapsulation efficacy and the zeta potential increased to 80.65 ± 6.79% and -26.7 ± 0.46 mV, respectively, compared to the normal CAT3 loaded SLN. As indicated by the high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) quantitation, the monolayer cellular transepithelial transport rate of OA-CAT3-SLN improved by 2.42-fold relied on cholesterol compared to the CAT3 suspension. Hence, the in vitro cell viability of OA-CAT3-SLN in C6 glioma cells decreased to 29.77% ± 2.13% and 10.75% ± 3.12% at 48 and 72 h, respectively. Finally, compared to the CAT3 suspension, the in vivo pharmacokinetics in rats indicated that the plasma bioavailability and Cmax of PF403 as afforded by OA-CAT3-SLN increased by 1.7- and 5.5-fold, respectively. Overall, the results indicate that OA-CAT3-SLN could be an efficacious delivery system in the treatment of glioma.

An innovative in situ method of creating hybrid dendrimer nano-assembly: An efficient next generation dendritic platform for drug delivery

Dendrimers have proven to be effective for drug delivery and their biodisposition varies with change on their surface, generation and core. In an effort to understand the role of critical nanoscale design parameters, we developed a novel hybrid dendrimer approach to harness unique features of individual dendrimers and create a nano-assembly. We report an easy in situ method of creating hybrid dendrimer nano-assembly by mixing G4.0 PAMAM (-NH₂) and G3.5 PAMAM (-COONa) dendrimers with a chemotherapeutic drug docetaxel (DTX). Zeta potential, HR-TEM, ¹H-NMR proved the formation of nano-assembly. In vitro dissolution, release studies revealed pH dependent dissolution and sustained drug release. Cellular uptake, cytotoxicity, and flow cytometric analysis in human/mouse glioblastoma cells indicated the effectiveness of hybrid dendrimers. The oral administration of the hybrid dendrimers showed pharmacokinetic equivalence to intravenous injection of commercially available Taxotere®. Hybrid dendrimer concept provides much needed fine-tuning to create multistage next-generation dendritic platform in nanomedicine.

Development of Solid Lipid Nanoparticles by Cold Dilution of Microemulsions: Curcumin Loading, Preliminary In Vitro Studies, and Biodistribution

Background: Solid lipid nanoparticles (SLNs) are attractive drug delivery systems for lipophilic molecules like curcumin (CURC) with low chemical stability. Methods: A simple, innovative, and cold-operating method, named “cold dilution of microemulsion” is developed by the authors to produce SLNs. An oil-in-water microemulsion (µE), whose disperse phase consisted of a solution of trilaurin in a partially water-miscible solvent, was prepared after mutually saturating solvent and water. Trilaurin SLNs precipitated following solvent removal upon water dilution of the µE. After SLN characterization (mean size, Zeta potential, CURC entrapment efficiency, and over time stability), they were tested for in vitro cytotoxicity studies on pancreatic adenocarcinoma cell lines and for in vivo preliminary biodistribution studies in Wistar healthy rats. Results: CURC loaded SLNs (SLN-CURC) had mean diameters around 200 nm, were negatively charged, stable over time, and able to entrap CURC up to almost 90%, consequently improving its stability. SLN-CURC inhibited in vitro pancreatic carcinoma cell growth in concentration-dependent manner. Their in vivo intravenous administration suggested a possible long circulation. Conclusions: These results, according to a concomitant study on chitosan-coated SLNs, confirm the possibility to apply the developed SLN-based delivery systems as a means to entrap CURC, to improve both its water dispersibility and chemical stability, facilitating its application in therapy.

Protective effects of melatonin solid lipid nanoparticles on testis histology after testicular trauma in rats

Testicular traumatic injuries occur frequently, which can result in an alteration in spermatogenesis. These injuries can also cause oxidative stress and male infertility. Antioxidant efficiency of melatonin (MLT), known as a potent antioxidant, will be improved if used in a form of solid lipid nanoparticles (MLT-SLN). The aim of the current study is to evaluate the effect of MLT-loaded SLN on traumatic testis in rats. In this study 32 adult male Wistar rats were divided into 4 groups. Group 1 (sham group), right testicle was drawn out from the scrotum and returned without manipulation. Group 2, right testicle was dropped by 25 g sinker for 4 times. Group 3, animals were received a single dose (25 mg/kg) of MLT intraperitoneally after trauma. Group 4, animals were received a single dose of MLT-SLN intraperitoneally after trauma. Under anaesthesia, rats were sacrificed, and their testicles were removed three days after the surgery. After tissue processing, the sample sections were H&E stained. MLT and MLT-SLN could partially repair spermatogenesis by Johnson’s criteria but the repairs were significant only in MLT-SLN group (P = 0.02). Trauma decreased seminiferous tubule diameter and its epithelium height. MLT could restore epithelium height (P ≤ 0.05) but its NPs improved both epithelium diameter (P ≤ 0.05) and thickness (P ≤ 0.001). The Malondialdehyde increased significantly in trauma group (P = 0.002), but decreased in MLT and NPs groups compared to trauma group (P = 0.098 and P = 0.002 respectively). This decrease was significant only in NPs group. Testicular trauma disturbed spermatogenesis, morphometric, and oxidative parameters. MLT and specially MLT-SLN improved traumatic damages.

Solid Lipid Nanoparticles for Dibucaine Sustained Release

Dibucaine (DBC) is among the more potent long-acting local anesthetics (LA), and it is also one of the most toxic. Over the last decades, solid lipid nanoparticles (SLN) have been developed as promising carriers for drug delivery. In this study, SLN formulations were prepared with the aim of prolonging DBC release and reducing its toxicity. To this end, SLN composed of two different lipid matrices and prepared by two different hot-emulsion techniques (high-pressure procedure and sonication) were compared. The colloidal stability of the SLN formulations was tracked in terms of particle size (nm), polydispersity index (PDI), and zeta potential (mV) for 240 days at 4 °C; the DBC encapsulation efficiency was determined by the ultrafiltration/centrifugation method. The formulations were characterized by differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR), and release kinetic experiments. Finally, the in vitro cytotoxicity against 3T3 fibroblast and HaCaT cells was determined, and the in vivo analgesic action was assessed using the tail flick test in rats. Both of the homogenization procedures were found suitable to produce particles in the 200 nm range, with good shelf stability (240 days) and high DBC encapsulation efficiency (~72⁻89%). DSC results disclosed structural information on the nanoparticles, such as the lower crystallinity of the lipid core vs. the bulk lipid. EPR measurements provided evidence of DBC partitioning in both SLNs. In vitro (cytotoxicity) and in vivo (tail flick) experiments revealed that the encapsulation of DBC into nanoparticles reduces its intrinsic cytotoxicity and prolongs the anesthetic effect, respectively. These results show that the SLNs produced are safe and have great potential to extend the applications of dibucaine by enhancing its bioavailability.

Electron Paramagnetic Resonance and Small-Angle X-ray Scattering Characterization of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for Dibucaine Encapsulation

Dibucaine (DBC) is one of the most potent long-acting local anesthetics, but it also has significant toxic side effects and low water solubility. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have been proposed as drug-delivery systems to increase the bioavailability of local anesthetics. The purpose of the present study was to characterize SLNs and NLCs composed of cetyl palmitate or myristyl myristate, a mixture of capric and caprylic acids (for NLCs only) plus Pluronic F68 prepared for the encapsulation of DBC. We intended to provide a careful structural characterization of the nanoparticles to identify the relevant architectural parameters that lead to the desirable biological response. Initially, SLNs and NLCs were assessed in terms of their size distribution, morphology, surface charge, and drug loading. Spectroscopic techniques (infrared spectroscopy and electron paramagnetic resonance, EPR) plus small-angle X-ray scattering (SAXS) provided information on the interactions between nanoparticle components and their structural organization. The sizes of nanoparticles were in the 180 nm range with low polydispersity and negative zeta values (-25 to -46 mV). The partition coefficient of DBC between nanoparticles and water at pH 8.2 was very high (>10⁴). EPR (with doxyl-stearate spin labels) data revealed the existence of lamellar arrangements inside the lipid nanoparticles, which was also confirmed by SAXS experiments. Moreover, the addition of DBC increased the molecular packing of both SLN and NLC lipids, indicative of DBC insertion between the lipids, in the milieu assessed by spin labels. Such structural information brings insights into understanding the molecular organization of these versatile drug-delivery systems which have already demonstrated their potential for therapeutic applications in pain control.

Solid lipid nanoparticles optimized by 22 factorial design for skin administration: Cytotoxicity in NIH3T3 fibroblasts

The present study focuses on the characterization of the cytotoxic profile on NIH3T3 mouse embryonic fibroblasts of solid lipid nanoparticles (SLN) optimized by a 2² full factorial design for skin administration. To build up the surface response charts, a design of experiments (DoE) based on 2 independent variables was used to obtain an optimized formulation. The effect of the composition of lipid and water phases on the mean particle size (z-AVE), polydispersity index (PdI) and zeta potential (ZP) was studied. The developed formulations were composed of 5.0% of lipid phase (stearic acid (SA), behenic alcohol (BA) or a blend of SA:BA (1:1)) and 4.7% of surfactants (soybean phosphatidylcholine and poloxamer 407). In vitro cytotoxicity using NIH3T3 fibroblasts was performed by MTT reduction assay. This factorial design study has proven to be a useful tool in optimizing SLN (z-AVE ∼ 200 nm), which were shown to be non-cytotoxic. The present results highlight the benefit of applying statistical designs in the preparation and optimization of SLN formulations.

Antimycobacterial susceptibility evaluation of rifampicin and isoniazid benz-hydrazone in biodegradable polymeric nanoparticles against Mycobacterium tuberculosis H37Rv strain

INTRODUCTION

Tuberculosis (TB) is the single largest infectious disease which requires a prolonged treatment regime with multiple drugs. The present treatment for TB includes frequent administration of a combination of four drugs for a duration of 6 months. This leads to patient's noncompliance, in addition to developing drug-resistant strains which makes treatment more difficult. The formulation of drugs with biodegradable polymeric nanoparticles (NPs) promises to overcome this problem.

MATERIALS AND METHODS

In this study, we focus on two important drugs used for TB treatment - rifampicin (RIF) and isoniazid (INH) - and report a detailed study of RIF-loaded poly lactic-co-glycolic acid (PLGA) NPs and INH modified as INH benz-hydrazone (IH2) which gives the same therapeutic effect as INH but is more stable and enhances the drug loading in PLGA NPs by 15-fold compared to INH. The optimized formulation was characterized using particle size analyzer, scanning electron microscopy and transmission electron microscopy. The drug release from NPs and stability of drug were tested in different pH conditions.

RESULTS

It was found that RIF and IH2 loaded in NPs release in a slow and sustained manner over a period of 1 month and they are more stable in NPs formulation compared to the free form. RIF- and IH2-loaded NPs were tested for antimicrobial susceptibility against Mycobacterium tuberculosis H37Rv strain. RIF loaded in PLGA NPs consistently inhibited the growth at 70% of the minimum inhibitory concentration (MIC) of pure RIF (MIC level 1 µg/mL), and pure IH2 and IH2-loaded NPs showed inhibition at MIC equivalent to the MIC of INH (0.1 µg/mL).

CONCLUSION

These results show that NP formulations will improve the efficacy of drug delivery for TB treatment.

Pomegranate extract-loaded solid lipid nanoparticles: design, optimization, and in vitro cytotoxicity study

Background

Pomegranate extract (PE) is a natural product with potent antioxidant and anticancer activity because of its polyphenols content. The main purpose of this study was to maximize the PE chemotherapeutic efficacy by loading it in an optimized solid lipid nanoparticles (SLNs) formula.

Materials and methods

The influence of independent variables, which were lipid concentration (X₁), surfactant concentration (X₂) and cosurfactant concentration (X₃), on dependent ones, which were particle size (Y₁), polydispersity index (Y₂), zeta potential (Y₃), entrapment efficiency (Y₄) and cumulative % drug release (Y₅), were studied and optimized using the Box–Behnken design. Fifteen formulations of PE-SLNs were prepared using hot homogenization followed by ultra-sonication technique. Response surface plots, Pareto charts and mathematical equations were produced to study the impact of independent variables on the dependent quality parameters. The anti-proliferative activity of the optimized formula was then evaluated in three different cancer cell lines, namely, MCF-7, PC-3 and HepG-2, in addition to one normal cell line, HFB-4.

Results

The results demonstrated that the particle sizes ranged from 407.5 to 651.9 nm and the entrapment efficiencies ranged from 56.02 to 65.23%. Interestingly, the 50% inhibitory concentration of the optimized formula had more than a 40-fold improved effect on the cell growth inhibition in comparison with its free counterpart. Furthermore, it was more selective against cancer cells than normal cells particularly in MCF-7 breast cancer cells.

Conclusion

These data proved that nanoencapsulation of PE enhanced its anticancer efficacy. Therefore, our results suggested that a PE-loaded SLNs optimized-formula could be a promising chemo therapeutic agent.

Dermal anti-oxidant, anti-inflammatory and anti-aging effects of Compritol ATO-based Resveratrol colloidal carriers prepared using mixed surfactants

In this study, Compritol ATO-based Resveratrol colloidal carriers (CCCs) were prepared and subjected to characterization and evaluation. In most formulae, the use of a binary-mixture of surfactants improved the physicochemical properties. CCC6 (containing P407/P188 as bi-surfactants) attained the highest drug loading, release efficiency during 24 h and occlusive effect for 48 h; in addition, it showed a uniform particle size distribution within the desired range. In-vivo studies were done based on the analysis of anti-oxidant markers [catalase (CAT), reduced glutathione (GSH) and superoxide dismutase (SOD)], anti-inflammatory markers [interleukin 6 (IL-6), interleukin 8 (IL-8) and rat Nuclear factor-kappa B (NF-κB)] and anti-wrinkling markers [matrix metalloproteinase (MMP-1) and Granulocyte-macrophage colony-stimulating factor (GM-CSF)], after UVB-irradiation. Results were significantly different when comparing the positive control and the negative control groups (p < 0.05). Rats pre-treated with CCC6 showed a great amelioration, and the level of the biochemical markers was significantly different compared to those of the positive control group and those pre-treated with the drug suspension (p < 0.05). Also, the high skin protective effect of CCC6 was proved by visual and histopathological examination of the rats' skin. Therefore, the current study proves the beneficial effects of the designed dermal Resveratrol-loaded colloidal system.

Solid lipid nanoparticles for the controlled delivery of poorly water soluble non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (IBP) are among the most prescribed drugs across the globe. However, most NSAIDs are insoluble in water leading them to have poor bioavailability and erratic absorption. Moreover, NSAIDs such as IBP and ketoprofen (KP) have to be administered very frequently due to their short plasma half-life leading to side effects. Controlled release formulations of IBP, KP and nabumetone (NBT) based on solid lipid nanoparticles (SLNs) were successfully synthesised in the present study to solve the above-mentioned challenges that are associated with NSAIDs. SLNs were prepared in two steps; hot-melt homogenization followed by sonication to formulate SLNs with spherical morphology. While capmul® GMS-50K (capmul) was used as the lipid due to the high solubility of the studied drugs in it, gelucire® 50/13 (gelucire) was used as the surfactant. It was found that particle size was directly proportional to drug concentration and inversely proportional to surfactant concentration, volume of water added and temperature of water. Ultrasonication in a pulse mode with optimum duration of 15min was essential to obtain smaller nanoparticles through the formation of a nanoemulsion. Drug loaded SLNs with small particle size and narrow size distribution with good solid loading, encapsulation efficiency and drug loading percentage could be prepared using the optimised conditions. SLNs prepared at the optimised condition were characterized thoroughly by using different techniques such as dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The cytotoxicity results showed that the prepared SLNs are non-toxic to Raw cell line. The drugs IBP, KP and NBT showed 53, 74 and 69% of percentage entrapment efficiency with drug loading of 6, 2 and 7% respectively. Slow, steady and sustained drug release was observed from the SLNs for over 6days.

Sustained release docetaxel-incorporated lipid nanoparticles with improved pharmacokinetics for oral and parenteral administration

The aim of this study was to develop docetaxel-incorporated lipid nanoparticles (DTX-NPs) to improve the pharmacokinetic behaviour of docetaxel (DTX) after oral and parenteral administration via sustained release. DTX-NPs were prepared by nanotemplate engineering technique with palmityl alcohol as a solid lipid and Tween-40/Span-40/Myrj S40 as a surfactants mixture. Spherical DTX-NPs below 100 nm were successfully prepared with a narrow particle size distribution, 96% of incorporation efficiency and 686 times increase in DTX solubility. DTX-NPs showed a sustained release over 24 h in phosphate-buffered saline and simulated gastric and intestinal fluids, while DTX-micelles released DTX completely within 12 h. The half-maximal inhibitory concentration (IC₅₀) of DTX-NPs against human breast cancer MCF-7 cells was 1.9 times lower than that of DTX-micelles and DTX solution. DTX-NPs demonstrated 3.7- and 2.8-fold increase in the area under the plasma concentration-time curve compared with DTX-micelles after oral and parenteral administration, respectively.