A Novel Chitosan-coated Leciplex Loaded with Ambrisentan as a Possible Pulmonary Nanosystem: Optimization, Characterization, and Pharmacokinetics Assessments.

The purpose of this research was to formulate, optimize, and characterize ambrisentan chitosan-coated LeciPlex (AMS-CTS-LPX) to increase the therapeutic effectiveness and bioavailability of ambrisentan. A central composite design (CCD) was implemented to assess the impact of various factors on the production of AMS-CTS-LPX and to identify the optimum formulation via the use of Design Expert® software. The assembly of AMS-CTS-LPX was conducted using a single-step process. Subsequently, the optimal formulation was chosen and subjected to further assessments. Further, a comparative pharmacokinetic study was carried out using a rat model. The optimized formulation exhibited an entrapment efficiency of 82.39%, with a diameter of 137.53 nm and a surface charge of +43.65 mV. Additionally, it had a sustained cumulative release of 90.41% after 8 h and showed good stability. The safety of AMS-CTS-LPX administered intratracheally was confirmed by in vivo histopathological studies. The pharmacokinetic investigations revealed a 5.6-fold increase in the bioavailability of AMS from the optimal AMS-CTS-LPX formulation compared to the oral AMS solution. Collectively, the results of the current study suggest that CTS-LPX may be beneficial as a pulmonary nanosystem for the administration of AMS.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: II. Antidepressant Effect in an Experimental Animal Model.

Depression is a serious mental disorder and the most prevalent cause of disability and suicide worldwide. Quercetin (QER) demonstrated antidepressant effects in rats exhibiting anxiety and depressive-like behaviors. In an attempt to improve QER's antidepressant activity, a QER-loaded transferosome (QER-TFS) thermosensitive gel for intranasal administration was formulated and optimized. The therapeutic effectiveness of the optimized formulation was assessed in a depressed rat model by conducting a behavioral analysis. Behavioral study criteria such as immobility, swimming, climbing, sucrose intake, number of crossed lines, rearing, active interaction, and latency to feed were all considerably enhanced by intranasal treatment with the QER-TFS in situ gel in contrast to other formulations. A nasal histopathological study indicated that the QER-TFS thermosensitive gel was safe for the nasal mucosa. An immunohistochemical analysis showed that the animals treated with the QER-TFS thermosensitive gel had the lowest levels of c-fos protein expression, and brain histopathological changes in the depressed rats were alleviated. According to pharmacodynamic, immunohistochemical, and histopathological experiments, the intranasal administration of the QER-TFS thermosensitive gel substantially alleviated depressive symptoms in rats. However, extensive preclinical investigations in higher animal models are needed to anticipate its effectiveness in humans.

Novel nasal niosomes loaded with lacosamide and coated with chitosan: A possible pathway to target the brain to control partial-onset seizures.

This work aimed to develop and produce lacosamide-loaded niosomes coated with chitosan (LCA-CTS-NSM) using a thin-film hydration method and the Box-Behnken design. The effect of three independent factors (Span 60 amount, chitosan concentration, and cholesterol amount) on vesicle size, entrapment efficiency, zeta potential, and cumulative release (8 h) was studied. The optimal formulation of LCA-CTS-NSM was chosen from the design space and assessed for morphology, in vitro release, nasal diffusion, stability, tolerability, and in vivo biodistribution for brain targeting after intranasal delivery. The vesicle size, entrapment, surface charge, and in vitro release of the optimal formula were found to be 194.3 nm, 58.3%, +35.6 mV, and 81.3%, respectively. Besides, it exhibits sustained release behavior, enhanced nasal diffusion, and improved physical stability. Histopathological testing revealed no evidence of toxicity or structural damage to the nasal mucosa. It demonstrated significantly more brain distribution than the drug solution. Overall, the data is encouraging since it points to the potential for non-invasive intranasal administration of LCA as an alternative to oral or parenteral routes.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: I. Optimization, Characterization, Brain Localization, and Cytotoxic Studies.

Numerous neurological disorders have a pathophysiology that involves an increase in free radical production in the brain. Quercetin (QER) is a nutraceutical compound that shields the brain against oxidative stress-induced neurodegeneration. Nonetheless, its low oral bioavailability diminishes brain delivery. Therefore, the current study aimed to formulate QER-loaded transferosomal nanovesicles (QER-TFS) in situ gel for QER brain delivery via the intranasal route. This study explored the impacts of lipid amount, edge activator (EA) amount, and EA type on vesicle diameter, entrapment, and cumulative amount permeated through nasal mucosa (24 h). The optimum formulation was then integrated into a thermosensitive gel after its physical and morphological characteristics were assessed. Assessments of the optimized QER-TFS showed nanometric vesicles (171.4 ± 3.4 nm) with spherical shapes and adequate entrapment efficiency (78.2 ± 2.8%). The results of short-term stability and high zeta potential value (-32.6 ± 1.4 mV) of QER-TFS confirmed their high stability. Compared with the QER solution, the optimized QER-TFS in situ gel formulation exhibited sustained release behavior and augmented nasal mucosa permeability. CT scanning of rat brains demonstrated the buildup of gold nanoparticles (GNPs) in the brains of all treatment groups, with a greater level of GNPs noted in the rats given the transferosomal gel. Additionally, in vitro studies on PCS-200-014 cells revealed minimal cytotoxicity of QER-TFS in situ gel. Based on these results, the developed transferosomal nanovesicles may be a suitable nanocarrier for QER brain targeting through the intranasal route.

Chitosan on the surface of nanoparticles for enhanced drug delivery: A comprehensive review.

The ability of chitosan (CTS) to promote mucoadhesion, trigger positive/negative surface interactions, and open tight junctions has inspired researchers to coat lipid-based and polymeric-based nanoparticles with CTS in an attempt to reach new heights in the delivery of drugs and nutraceuticals across different routes. This article discusses literature relevant to the pharmaceutical and biomedical area published in the last 10 years on nanoparticles overlaid with CTS. Herein, we addressed the technical aspects of the coating procedure by adding CTS solution to nanoparticles that have already been produced or during the production phase. Besides, we reviewed the applications of CTS coated nanoparticles as drug delivery systems in the oral and non-oral routes of administrations. Special attention was paid to the physicochemical and biological benefits of the CTS coating, such as improving physicochemical stability, enhancing cell and tissue interactions, controlled drug release, and augmentation of active substance bioavailability and efficacy. Moreover, this review projects the current standing and future prospects of the delivery system. The future calls for more investigations on therapeutic proteins, genes and vaccines as potential cargos. Extensive studies on the merits of integrating CTS with hydropolymer-synthesized nanoparticles and using longer-chain and chemically-modified variants of CTS are also warranted.

Bilosomes as a promising nanoplatform for oral delivery of an alkaloid nutraceutical: improved pharmacokinetic profile and snowballed hypoglycemic effect in diabetic rats.

Diabetes mellitus is a life-threatening metabolic disease. At the moment, there is no effective treatment available to combat it. In this study, we aimed to develop berberine-loaded bilosomes (BER-BLS) to boost the oral bioavailability and therapeutic efficacy of berberine, a natural antidiabetic medication. The BER-BLS was fabricated using a thin-film hydration strategy and optimized using a central composite design (face-centered). The average vesicle size, entrapment efficiency, and surface charge of the optimized BER-BLS preparation were 196.5 nm, 89.7%, (-) 36.4 mV, respectively. In addition, it exhibited higher stability and better-sustained release of berberine than the berberine solution (BER-SOL). BER-BLS and BER-SOL were administered to streptozocin-induced diabetic rats. The optimized BER-BLS formulation had a significant hypoglycemic impact, with a maximum blood glucose decrease of 41%, whereas BER-SOL only reduced blood glucose by 19%. Furthermore, the pharmacological effect of oral BER-BLS and BER-SOL corresponded to 99.3% and 31.7%, respectively, when compared to subcutaneous insulin (1 IU). A pharmacokinetic analysis found a 6.4-fold rise in the relative bioavailability of berberine in BER-BLS when compared to BER-SOL at a dosage of 100 mg/kg body weight. Histopathological investigation revealed that BER-BLS is suitable for oral administration. Our data demonstrate that BLS is a potential nanocarrier for berberine administration, enhancing its oral bioavailability and antidiabetic activity.

Intranasal Delivery of Granisetron to the Brain via Nanostructured Cubosomes-Based In Situ Gel for Improved Management of Chemotherapy-Induced Emesis.

This research aimed to boost granisetron (GS) delivery to the brain via the intranasal route to better manage chemotherapy-induced emesis. Glycerol monooleate (GMO), Poloxamer 407 (P 407) and Tween 80 (T 80) were used to formulate GS-loaded cubosomes (GS-CBS) utilizing a melt dispersion-emulsification technique. GS-CBS were characterized by testing particle diameter, surface charge and entrapment efficiency. The formulations were optimized using a Box-Behnken statistical design, and the optimum formula (including GMO with a concentration of 4.9%, P 407 with a concentration of 10%, and T 80 with a concentration of 1%) was investigated for morphology, release behavior, ex vivo permeation through the nasal mucosa, and physical stability. Moreover, the optimal formula was incorporated into a thermosensitive gel and subjected to histopathological and in vivo biodistribution experiments. It demonstrated sustained release characteristics, increased ex vivo permeability and improved physical stability. Moreover, the cubosomal in situ gel was safe and biocompatible when applied to the nasal mucosa. Furthermore, compared to a drug solution, the nose-to-brain pathway enhanced bioavailability and brain distribution. Finally, the cubosomal in situ gel may be a potential nanocarrier for GS delivery to the brain through nose-to-brain pathway.

Fabrication and In Vitro/In Vivo Appraisal of Metronidazole Intra-Gastric Buoyant Sustained-Release Tablets in Healthy Volunteers.

Helicobacter pylori is thought to be the most common cause of peptic and duodenal ulcers. Eradication of this organism is now considered one of the lines of treatment of gastric and duodenal ulcers. This can be achieved via local delivery of antibacterial agents in high concentrations. Accordingly, our objective was to fabricate and evaluate sustained release floating tablets for metronidazole to extend the gastric residence period and control the release rate of metronidazole. Floating tablets containing cellulose derivatives and Avicel were prepared using direct compression. The rate of metronidazole release from the floating tablets (K = 6.278 mg min-1/2) was significantly lower than that from conventional tablets (K = 10.666 mg min-1/2), indicating sustained drug release, according to the Higuchi model, for more than 6 h in an acidic medium of 0.1 N HCl. In vivo study in healthy volunteers revealed significantly improved bioavailability; increased Tmax, AUC, and MRT; and significantly lower absorption rate constant after a single oral dose of 150 mg metronidazole as floating tablets. In addition, the significant increase in MRT indicated an in vivo sustained drug release. The floating tablets provided several benefits, including ease of preparation, absence of effervescent ingredients, and reliance on a pH-independent gel-forming agent to deliver metronidazole in a sustained manner. In conclusion, the prepared tablets could be promising for enhancing both local and systemic metronidazole efficacy.

Surface-Modified Bilosomes Nanogel Bearing a Natural Plant Alkaloid for Safe Management of Rheumatoid Arthritis Inflammation.

Rheumatoid arthritis (RA) is a chronic inflammatory illness affecting the joints. The characteristic of RA is gradual joint deterioration. Current RA treatment alleviates signs such as inflammation and pain and substantially slows the progression of the disease. In this study, we aimed to boost the transdermal delivery of berberine (a natural product) by encapsulating it in chitosan, surface-modified bilosomes nanogel for better management of the inflammation of RA. The chitosan-coated bilosomes loaded with berberine (BER-CTS-BLS) were formulated according to the thin-film hydration approach and optimized for various causal variables, considering the effect of lipid, sodium deoxycholate, and chitosan concentrations on the size of the particles, entrapment, and the surface charge. The optimized BER-CTS-BLS has 202.3 nm mean diameter, 83.8% entrapment, and 30.8 mV surface charge. The optimized BER-CTS-BLS exhibited a delayed-release profile in vitro and increased skin permeability ex vivo. Additionally, histological examination revealed that the formulated BLS had no irritating effects on the skin. Furthermore, the optimized BER-CTS-BLS ability to reduce inflammation was evaluated in rats with carrageenan-induced paw edema. Our results demonstrate that the group treated with topical BER-CTS-BLS gel exhibited a dramatic reduction in rat paw edema swelling percentage to reach 24.4% after 12 h, which was substantially lower than other groups. Collectively, chitosan-coated bilosomes containing berberine have emerged as a promising therapeutic approach to control RA inflammation.

Lipid Nanocarriers Overlaid with Chitosan for Brain Delivery of Berberine via the Nasal Route.

This research aimed to design, optimize, and evaluate berberine-laden nanostructured lipid carriers overlaid with chitosan (BER-CTS-NLCs) for efficient brain delivery via the intranasal route. The nanostructured lipid carriers containing berberine (BER-NLCs) were formulated via hot homogenization and ultrasonication strategy and optimized for the influence of a variety of causal variables, including the amount of glycerol monostearate (solid lipid), poloxamer 407 (surfactant) concentration, and oleic acid (liquid lipid) amount, on size of the particles, entrapment, and the total drug release after 24 h. The optimal BER-NLCs formulation was then coated with chitosan. Their diameter, in vitro release, surface charge, morphology, ex vivo permeability, pH, histological, and in vivo (pharmacokinetics and brain uptake) parameters were estimated. BER-CTS-NLCs had a size of 180.9 ± 4.3 nm, sustained-release properties, positive surface charge of 36.8 mV, and augmented ex-vivo permeation via nasal mucosa. The histopathological assessment revealed that the BER-CTS-NLCs system is safe for nasal delivery. Pharmacokinetic and brain accumulation experiments showed that animals treated intranasally with BER-CTS-NLCs had substantially greater drug levels in the brain. The ratios of BER brain/blood levels at 30 min, AUCbrain/AUCblood, drug transport percentage, and drug targeting efficiency for BER-CTS-NLCs (IN) were higher compared to BER solution (IN), suggesting enhanced brain targeting. The optimized nanoparticulate system is speculated to be a successful approach for boosting the effect of BER in treating CNS diseases, such as Alzheimer's disease, through intranasal therapy.

Potential Use of Tailored Citicoline Chitosan-Coated Liposomes for Effective Wound Healing in Diabetic Rat Model.

PURPOSE: This study aimed to formulate citicoline-loaded chitosan-coated liposomes (CT-CS-LPs) for topical administration and evaluated for wound healing in a diabetic animal model. METHODS: CT-LPs were formulated via a thin-film hydration approach and coated with chitosan (CS). Box-Behnken statistical design investigated the effects of lipid amount, chitosan concentration, and cholesterol amount on vesicle diameter, surface charge, and entrapment efficiency. The potential of the optimized CT-CS-LPs gel for wound healing was further evaluated in streptozocin-induced diabetic rats. The different healing stages were evaluated by several techniques, including general and special staining techniques, in addition to antibody immunohistochemistry. RESULTS: The optimized CT-CS-LPs obtained had a mean size of 211.6 nm, a 50.7% entrapment efficiency, and a positive surface charge of 32.1 mV. In addition, the optimized CT-CS-LPs exhibited in vitro sustained release behavior. The in vivo experiments revealed that treatment with the optimized CT-CS-LPs boosts the healing process of the skin wound in diabetic rats by reducing inflammation, accelerating re-epithelization, angiogenesis, fibroblast proliferation, and connective tissue remodeling, leading to rapid wound closure. CONCLUSION: Chitosan-coated liposomes containing citicoline have emerged as a potential approach for promoting the healing process in diabetic rats. However, the therapeutic effectiveness of the suggested approach in diabetic patients needs to be investigated.

Berberine Encapsulated Lecithin-Chitosan Nanoparticles as Innovative Wound Healing Agent in Type II Diabetes.

The aim of this research is to formulate a lecithin-chitosan based nanoparticulate system loaded with berberine (BER-LC-CTS-NPs) that could be integrated into a topically applied formulation and assessed for healing wounds in a diabetic animal model. In order to formulate BER-LC-CTS-NPs, soybean lecithin, isopropyl myristate, and berberine dispersed in ethanolic solution were added into an aqueous solution of chitosan dropwise with sonication. We assessed the influence of lecithin amount, chitosan amount, and isopropyl myristate concentration on particle diameter, zeta potential, and entrapment and employed a Box-Behnken statistical design. The resulting optimized BER-LC-CTS-NPs had a mean size of 168.4 nm, a surface charge of 33.1 mV, and entrapment of 82.3%. The optimized BER-LC-CTS-NPs showed a sustained in vitro release profile. Furthermore, the potential of the optimized BER-LC-CTS-NPs integrated into a topical gel formulation for wound healing in streptozocin-induced diabetic rats was assessed. Our findings show that combining chitosan and berberine in the nanoparticles produces a synergistic effect when it comes to wound healing. The optimized nanoparticulate system works by reducing inflammation, inducing blood vessels and fibroblast proliferation, and promoting mature collagen fibers deposition. Based on the experimental results, lecithin-chitosan nanoparticles loaded with berberine have evolved as a promising strategy for accelerating wound the healing process in diabetic patients. However, the clinical merits of the developed system need to be investigated in diabetic patients.

Novel Chitosan-Coated Niosomal Formulation for Improved Management of Bacterial Conjunctivitis: A Highly Permeable and Efficient Ocular Nanocarrier for Azithromycin.

In the present study, we aimed to formulate, optimize, and characterize azithromycin chitosan coated niosomes (AZM-CTS-NSM) as a novel colloidal system that increases precorneal residence period, eye permeation, and bioavailability. AZM-NSM was formulated via a modified thin-film hydration strategy and then coated with CTS. We assessed the influence of the cholesterol: surfactant molar ratio, CTS concentration, and surfactant type on particle diameter, entrapment, zeta potential, and NSM adhesion force to the corneal mucosal membrane and employed a central composite design (CCD). The resulting optimized AZM-CTS-NSM has a mean diameter of 376 nm, entrapment of 74.2%, surface charge of 32.1 mV, and mucoadhesion force of 3114 dyne/cm2. The optimized AZM-CTS-NSM demonstrated a prolonged in vitro release behavior. When compared with commercial eye drops, the optimized AZM-CTS-NSM produced a 2.61-fold increase in the apparent permeability coefficient, significantly improving corneal permeability. Additionally, ocular irritation was assessed, with no major irritant effects found to be induced by the formulated NSM. Compared with AZM commercial drops, the optimized AZM-CTS-NSM revealed ˃ 3-fold increase in AZM concentration in the rabbit eyes. Collectively, these findings indicate that CTS-NSM is a potentially valuable ocular nanocarrier that could augment the efficacy of AZM.

Development and machine-learning optimization of mucoadhesive nanostructured lipid carriers loaded with fluconazole for treatment of oral candidiasis.

The aim of this work was to prepare and optimize mucoadhesive nanostructured lipid carrier (NLC) impregnated with fluconazole for better management of oral candidiasis. The NLCs were fabricated using an emulsification/sonication technique. The nanoparticles consisted of stearic acid, oleic acid, Pluronic F127, and lecithin. Box-Behnken design, artificial neural networking, and variable weight desirability were employed to optimize the joint effect of drug concentration in the drug/lipid mixture, solid lipid concentration in the solid/liquid lipid mixture, and surfactant concentration in the total mixture on size and entrapment. The optimized NLCs were coated with chitosan. The nanoparticles were characterized by surface charge, spectroscopic, thermal, morphological, mucoadhesion, release, histopathological, and antifungal properties. The nanoparticles are characterized by a particle size of 335 ± 13.5 nm, entrapment efficiency of 73.1 ± 4.9%, sustained release, minor histopathological effects on rabbit oral mucosa, and higher fungal inhibition efficiency for an extended period of time compared with fluconazole solution. Coating the nanoparticles with chitosan increased its adhesion to rabbit oral buccal mucosa and improved its anti-candidiasis activity. It is concluded that mucoadhesive lipid-based nanoparticles amplify the effect of fluconazole on Candida albicans in vitro. This finding warrants pre-clinical and clinical studies in oral candidiasis disease models to corroborate in vitro findings.

Development, Optimization, and In Vitro/In Vivo Characterization of Enhanced Lipid Nanoparticles for Ocular Delivery of Ofloxacin: the Influence of Pegylation and Chitosan Coating.

This study aims to investigate whether modification of solid lipid nanoparticles (SLNs) with chitosan (CTS) and polyethylene glycol (PEG) coatings enhances corneal retention time and transcorneal bioavailability. Ofloxacin (OFLOX) was selected as the model drug because of its potential benefits for the treatment of local eye infections. The OFLOX-CTS-PEG-SLN was prepared by a modified emulsion/solvent evaporation technique. A central composite design was implemented to investigate the influence of total lipid/drug ratio, surfactant concentration, PEG stearate concentration in the lipid mixture, and CTS concentration on size, entrapment, transcorneal permeation, and adhesion to the corneal mucosal membrane. The optimized OFLOX-CTS-PEG-SLN was characterized for OFLOX cumulative percentage released in simulated tear fluid and permeated across the excised bovine corneal membrane. Moreover, nanoparticle morphology, eye irritation via histopathological analysis, and OFLOX concentration in the ocular fluids and tissues were determined. A total lipid/drug ratio of 19:1, Tween 80 of 2%, PEG stearate concentration in the lipid mixture (% w/w) of 2.6%, and CTS concentration (% w/v) of 0.23% produced 132.9 nm particles entrapping 74.8% of the total drug added. The particles detached from the corneal membrane at a force of 3700 dyne/cm2. The %OFLOX released from the optimized nanoparticles was 63.3, and 66% of the drug permeated after 24 h. Compared to Oflox® drops, the optimized OFLOX-CTS-PEG-SLN exhibited similar tolerability but two- to threefold higher concentrations in the eyes of rabbits. Coating of SLN with chitosan and PEG augments the ocular bioavailability of OFLOX by increasing transcorneal permeation and enhancing mucoadhesion strength.

Development of a nanogel formulation for transdermal delivery of tenoxicam: a pharmacokinetic-pharmacodynamic modeling approach for quantitative prediction of skin absorption.

This study investigates potentials of solid lipid nanoparticles (SLN)-based gel for transdermal delivery of tenoxicam (TNX) and describes a pharmacokinetic-pharmacodynamic (PK-PD) modeling approach for predicting concentration-time profile in skin. A 23 factorial design was adopted to study the effect of formulation factors on SLN properties and determine the optimal formulation. SLN-gel tolerability was investigated using rabbit skin irritation test. Its anti-inflammatory activity was assessed by carrageenan-induced rat paw edema test. A published Hill model for in vitro inhibition of COX-2 enzyme was fitted to edema inhibition data. Concentration in skin was represented as a linear spline function and coefficients were estimated using non-linear regression. Uncertainty in predicted concentrations was assessed using Monte Carlo simulations. The optimized SLN was spherical vesicles (58.1 ± 3.1 nm) with adequate entrapment efficiency (69.6 ± 2.6%). The SLN-gel formulation was well-tolerated. It increased TNX activity and skin level by 40 ± 13.5, and 227 ± 116%, respectively. Average Cmax and AUC0-24 predicted by the model were 2- and 3.6-folds higher than the corresponding values computed using in vitro permeability data. SLN-gel is a safe and efficient carrier for TNX across skin in the treatment of inflammatory disorders. PK-PD modeling is a promising approach for indirect quantitation of skin deposition from PD activity data.

Topical ketoprofen nanogel: artificial neural network optimization, clustered bootstrap validation, and in vivo activity evaluation based on longitudinal dose response modeling.

OBJECTIVES: This work aimed at investigating the potential of solid lipid nanoparticles (SLN) as carriers for topical delivery of Ketoprofen (KP); evaluating a novel technique incorporating Artificial Neural Network (ANN) and clustered bootstrap for optimization of KP-loaded SLN (KP-SLN); and demonstrating a longitudinal dose response (LDR) modeling-based approach to compare the activity of topical non-steroidal anti-inflammatory drug formulations. METHODS: KP-SLN was fabricated by a modified emulsion/solvent evaporation method. Box-Behnken design was implemented to study the influence of glycerylpalmitostearate-to-KP ratio, Tween 80, and lecithin concentrations on particle size, entrapment efficiency, and amount of drug permeated through rat skin in 24 hours. Following clustered bootstrap ANN optimization, the optimized KP-SLN was incorporated into an aqueous gel and evaluated for rheology, in vitro release, permeability, skin irritation and in vivo activity using carrageenan-induced rat paw edema model and LDR mathematical model to analyze the time course of anti-inflammatory effect at various application durations. RESULTS: Lipid-to-drug ratio of 7.85 [bootstrap 95%CI: 7.63-8.51], Tween 80 of 1.27% [bootstrap 95%CI: 0.601-2.40%], and Lecithin of 0.263% [bootstrap 95%CI: 0.263-0.328%] were predicted to produce optimal characteristics. Compared with profenid® gel, the optimized KP-SLN gel exhibited slower release, faster permeability, better texture properties, greater efficacy, and similar potency. CONCLUSIONS: SLNs are safe and effective permeation enhancers. ANN coupled with clustered bootstrap is a useful method for finding optimal solutions and estimating uncertainty associated with them. LDR models allow mechanistic understanding of comparative in vivo performances of different topical formulations, and help design efficient dermatological bioequivalence assessment methods.