Development and Optimization of Itraconazole-Loaded Solid Lipid Nanoparticles for Topical Administration Using High Shear Homogenization Process by Design of Experiments: In Vitro, Ex Vivo and In Vivo Evaluation.

The aim of present study was to develop topical itraconazole (ITZ)-loaded solid lipid nanoparticles for treatment of superficial fungal infections. Formulations were prepared using high shear homogenization process, and optimized by employing a two-step design of experiments (DoE) approach. It comprised a Taguchi experimental design for screening of 'vital few' factors, and a central composite experimental design for optimization. Overlay of the response surface maps for percent drug entrapment (PDE), particle size, ITZ skin retention and permeation was performed to obtain the optimized ITZ-loaded SLNs (OPT-SLNs) suspension. The optimized ITZ-loaded SLNs (OPT-SLNs) showed mean particle size of (262.92 ± 8.56 nm) and zeta potential value of 22.36 mV. Excellent drug entrapment (94.21 ± 3.35%) and skin retention of ITZ (43.03 ± 1.86 µg/cm2) was achieved by OPT-SLNs. The hydrogel formulation of OPT-SLNs exhibited good gel consistency and spreadability characteristics. Pharmacodynamic and skin sensitivity studies in standardized rodent models revealed that OPT-SLNs hydrogel was more efficacious than conventional oral and topical antifungal therapies, and also safe for topical administration. Furthermore, the histoptahological evaluation depicted complete recovery of infected rats after 14-day treatment regimen of OPT-SLNs hydrogel. The developed formulation was found to have tremendous potential to enhance ITZ activity through topical administration approach.

Formulation, characterisation and in vivo evaluation of lipid-based nanocarrier for topical delivery of diflunisal.

Diflunisal (DIF) is non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis. The current engrossment was aimed at formulation and assessment of DIF-loaded solid lipid nanoparticles (SLNs) for topical/dermal application. SLNs formulated by hot homogenisation method based on microemulsification technique were spherical with a mean size of 124.0 ± 2.07 nm; PDI 0.294 ± 0.15. The cumulative amount permeated/area was 109.99 ± 0.008 µg/cm(2), along with permeation flux (6.30 ± 0.09 µg/cm(2)/h) and skin retention (11.74 ± 0.155 µg/cm(2)) across mice skin. The SLNs of DIF showed significant decrease in fluid volume, granuloma tissue weight, leukocyte count/mm(3) after application of SLN formulation in mice air pouch model. Similarly, in mice ear oedema and rat paw oedema model, there was 2.30 and 1.29 time increase in percentage inhibition of oedema after SLN formulation application, respectively, as compared with conventional cream. Hence, the SLNs of DIF may prove to be a potential nanocarrier to effectively treat the local inflammatory conditions associated with arthritis.

Microemulsion-Based Topical Hydrogels of Tenoxicam for Treatment of Arthritis.

Tenoxicam (TNX) is a non-steroidal anti-inflammatory drug (NSAID) used for the treatment of rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, backache and pain. However, prolonged oral use of this drug is associated with gastrointestinal adverse events like peptic ulceration, thus necessitating its development as topical formulation that could obviate the adverse effects and improve patient compliance. The present study was aimed at development of microemulsion-based formulations of TNX for topical delivery at the affected site. The pseudoternary phase diagrams were developed and microemulsion formulations were prepared using Captex 300/oleic acid as oil, Tween 80 as surfactant and n-butanol/ethanol as co-surfactant. Optimized microemulsions were characterized for drug content, droplet size, viscosity, pH and zeta potential. The ex vivo permeation studies through Laca mice skin were performed using Franz diffusion cell assembly, and the permeation profile of the microemulsion formulation was compared with aqueous suspension of drug and drug incorporated in conventional cream. Microemulsion formulations of TNX showed significantly higher (p < 0.001) mean cumulative percent permeation values in comparison to conventional cream and suspension of drug. In vivo anti-arthritic and anti-inflammatory activity of the developed TNX formulations was evaluated using various inflammatory models such as air pouch model, xylene-induced ear edema, cotton pellet granuloma and carrageenan-induced inflammation. Microemulsion formulations were found to be superior in controlling inflammation as compared to conventional topical dosage forms and showed efficacy equivalent to oral formulation. Results suggest that the developed microemulsion formulations may be used for effective topical delivery of TNX to treat various inflammatory conditions.

Development and Evaluation of Solid Lipid Nanoparticles of N-6-Furfuryl Adenine for Prevention of Photoaging.

N-6-furfuryl adenine (N6FA) also known as "kinetin" is a biologically active natural phytochemical. It belongs to the category of cytokinins, the natural plant growth hormones that promote cell division and play role in cell differentiation. Overall, N6FA aids in increasing the plant's life span. Human cells also contain.small quantities of N6FA. Scientists are trying to understand its function in humans. N6FA is being investigated for its properties such as antiplatelet, antioxidant, antiproliferative and anti-aging effects on human cells. The aim of the present investigation was to prepare solid lipid nanoparticle (SLN) based topical formulations of N6FA and to evaluate its efficacy against ultraviolet (UV) radiation induced skin photodamage. SLNs were prepared by hot microemulsion technique and optimized for the type and concentration of lipid and surfactant(s). The optimized SLN formulation was characterized in terms of particle size, drug entrapment efficiency, zeta potential and pH; evaluated for stability, spreadability, ex-vivo skin permeation and photoprotective effects against UV induced skin damage. The cumulative amount of drug permeated through mice skin using SLNs was 3 folds higher than from conventional cream base. The results of biochemical and histopathological investigations of skin treated with N6FA loaded SLNs clearly demonstrated the efficacy of optimized formulation in preventing photodamage (lesions, ulcers and changes in skin integrity) due to chronic UV exposure. The effects were comparable with widely used marketed formulation, Garnier wrinkle lift anti-aging cream. Results suggested that N6FA incorporated into SLNs may provide therapeutic as well as cosmeceutical benefits.

An ionic liquid-in-water microemulsion as a potential carrier for topical delivery of poorly water soluble drug: Development, ex-vivo and in-vivo evaluation.

In this paper, we report an ionic liquid-in-water (IL/w) microemulsion (ME) formulation which is able to solubilize etodolac (ETO), a poorly water soluble drug for topical delivery using BMIMPF6 (1-butyl-3-methylimidazolium hexafluorophosphate) as IL, Tween 80 as surfactant and ethanol as co-surfactant. The prepared ME was characterized for physicochemical parameters, subjected to ex-vivo permeation studies as well as in-vivo pharmacodynamic evaluation. The ex-vivo drug permeation studies through rat skin was performed using Franz-diffusion cell and the IL/w based ME showed maximum mean cumulative percent permeation of 99.030±0.921% in comparison to oil-in-water (o/w) ME (61.548±1.875%) and oily solution (48.830±2.488%) of ETO. In-vivo anti-arthritic and anti-inflammatory activities of the prepared formulations were evaluated using different rodent models and the results revealed that ETO loaded IL/w based ME was found to be more effective in controlling inflammation than oily solution, o/w ME and marketed formulation of ETO. Histopathological studies also demonstrated that IL/w based ME caused no anatomical and pathological changes in the skin.

Issues impacting therapeutic outcomes in pediatric patients: an overview.

The quest for achieving optimal therapeutic outcomes in pediatric patients has evaded the healthcare professionals for long and often lack of child specific dosage forms and the associated events that follow with it have been considered to be major contributor towards suboptimal outcomes. Consequently, there have been sustained efforts over the years to address this issue with the enactment of legislations like Best Pharmaceutical for Children Act (BPCA), Pediatric Research Equity Act (PREA) and Pediatric Regulation by European Union (EU) to incentivise the participation of pharmaceutical industry towards development of child friendly dosage forms. Initiatives taken in past by organisations like World Health Organisation (WHO) and Drugs for Neglected Diseases Initiative (DNDi) to spur the development of child friendly dosage forms has helped to address issues pertaining to management of Human Immunodeficiency Virus (HIV) and malaria in pediatric patients. Present efforts aimed at developing child friendly dosage forms include oro-dispersible platforms including thin films and mini-tablets. Despite these leaps and advancements in developing better dosage forms for children, lower therapeutic outcomes in pediatric patients continue to remain an unresolved issue because of detrimental effects of additional factors such as parents understanding of label instructions and complexities involved in executing pediatric clinical studies thus requiring a concerted effort from pharmaceutical companies, academic researchers, parents and healthcare providers to work for better treatment outcomes in children.

Ethosomes-based topical delivery system of antihistaminic drug for treatment of skin allergies.

Cetirizine is indicated for the treatment of allergic conditions such as insect bites and stings, atopic and contact dermatitis, eczema, urticaria. This investigation deals with development of a novel ethosome-based topical formulation of cetirizine dihydrochloride for effective delivery. The optimised formulation consisting of drug, phospholipon 90 G™ and ethanol was characterised for drug content, entrapment efficiency, pH, vesicular size, spreadability and rheological behaviour. The ex vivo permeation studies through mice skin showed highest permeation flux (16.300 ± 0.300 µg/h/cm(2)) and skin retention (20.686 ± 0.517 µg/cm(2)) for cetirizine-loaded ethosomal vesicles as compared to conventional formulations. The in vivo pharmacodynamic evaluation of optimised formulation was assessed against oxazolone-induced atopic dermatitis (AD) in mice. The parameters evaluated were reduction in scratching score, erythema score, skin hyperplasia and dermal eosinophil count. Our results suggest that ethosomes are effective carriers for dermal delivery of antihistaminic drug, cetirizine, for the treatment of AD.

Statistically designed nonionic surfactant vesicles for dermal delivery of itraconazole: characterization and in vivo evaluation using a standardized Tinea pedis infection model.

The study aims to statistically develop a hydrogel of itraconazole loaded nonionic surfactant vesicles (NSVs) for circumventing the shortcomings and adverse effects of currently used therapies. Influential factors were screened using first-order Taguchi design, thereafter, optimization was performed via D-optimal design involving screened factors (surfactant type, content and molar ratio of cholesterol: surfactant). Response variables investigated were percent drug entrapment, vesicle size, drug skin retention and permeation in 6h. Suspensions of NSVs were gelled to improve topical applicability. Characterization of formulations was performed using vesicle shape, size, surface charge, texture analysis and rheology behavior. Ex vivo studies in rat skin depicted that optimized formulation augmented drug skin retention and permeation in 6h than conventional cream and oily solution of itraconazole. Standardized Tinea pedis model in Wistar rats exhibited in vivo antifungal efficacy of optimized formulation, observed in terms of physical manifestations, fungal-burden score and histopathological profiles. Also, a unique investigation involving studying local oxidative stress of infected paw skins as an indicator of fungal infection was performed. Rapid alleviation of infection in animals treated with optimized hydrogel was observed in comparison to commonly prescribed therapies. Therefore, the optimized NSVs may be a promising and efficient alternative to available antifungal therapies.

Development of novel ionic liquid-based microemulsion formulation for dermal delivery of 5-Fluorouracil.

The present study was aimed at synthesizing an imidazole-based ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) and subsequent development of a novel ionic liquid-in-oil (IL/o) microemulsion (ME) system for dermal delivery of a poorly permeating drug 5-fluorouracil (5-FU). A significant enhancement in the solubility of 5-FU was observed in BMIMBr. IL/o MEs of 5-FU were prepared using isopropyl myristate, Tween 80/Span 20, and BMIMBr. Results of ex vivo skin permeation studies through mice skin indicated that the selected IL/o ME exhibited 4-fold enhancement in percent drug permeation as compared to aqueous solution, 2.3-fold as compared to hydrophilic ointment, and 1.6-fold greater permeation than water in oil (w/o) ME. The results of in vivo studies against dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mice skin carcinogenesis demonstrated that the IL/o ME could effectively treat skin cancer in 4 weeks. In addition, the side effects such as erythema and irritation associated with the conventional formulations were not observed. Histopathological studies showed that the use of IL/o ME caused no anatomic and pathological changes in the skin structure of mice. These studies suggest that the use of IL-based ME system can efficiently enhance the solubility and permeability of 5-FU and hence its therapeutic efficacy.

Novel flexible vesicles based topical formulation of levocetirizine: in vivo evaluation using oxazolone-induced atopic dermatitis in murine model.

BACKGROUND: Levocetirizine, an active enantiomer of cetirizine is third generation antihistaminic agent used for treating various allergies like atopic dermatitis, chronic idiopathic urticaria and allergic rhinitis. OBJECTIVE: Development of novel topical formulation of levocetirizine based on flexible vesicles (FVs) with an aim to have targeted peripheral antihistaminic effect. MATERIALS AND METHODS: The FVs were prepared by thin film hydration method and characterized for drug content, entrapment efficiency, pH, vesicular size, spreadability, morphological characteristics and drug leakage studies. Franz diffusion cell assembly was used to carry out the ex vivo permeation studies through mice skin and the permeation profile of the developed FV formulation was compared with conventional formulations of levocetirizine. RESULTS AND DISCUSSION: The ex vivo permeation studies revealed 1.78-fold increase in percent permeation of levocetirizine from FV formulation as compared to conventional formulations of levocetirizine in 8 h. Further, oxazolone induced atopic dermatitis murine model was selected to study the in vivo pharmacodynamic activity. The developed formulation was evaluated for scratching score, erythema score and histological evaluation. There was marked reduction in scratching score from 15.25 scratches/20 min with conventional levocetirizine cream to 6.75 scratches/20 min with application of levocetirizine FV formulation. Also, there was significant reduction in erythema score as well as dermal eosinophil count. Results of skin sensitivity and toxicity studies suggest that the developed formulation was dermally safe and nontoxic. CONCLUSION: A novel FVs based topical formulation of levocetirizine was successfully developed for treatment of atopic dermatitis.

Development of novel elastic vesicle-based topical formulation of cetirizine dihydrochloride for treatment of atopic dermatitis.

Cetirizine is a piperazine-derived second-generation antihistaminic drug recommended for treatment of pruritus associated with atopic dermatitis. The present investigation encompasses development of a nanosized novel elastic vesicle-based topical formulation of cetirizine dihydrochloride using combination of Phospholipon® 90G and edge activators with an aim to have targeted peripheral H1 antihistaminic activity. The formulation was optimized with respect to phospholipid/drug/charge inducer ratio along with type and concentration of edge activator. The optimized formulation was found to be satisfactory with respect to stability, drug content, entrapment efficiency, pH, viscosity, vesicular size, spreadability, and morphological characteristics. The ex vivo permeation studies through mice skin were performed using Franz diffusion cell assembly. It was found that the mean cumulative percentage amount permeated in 8 h was almost twice (60.001 ± 0.332) as compared to conventional cream (33.268 ± 0.795) and aqueous solution of drug (32.616 ± 0.969), suggesting better penetration and permeation of cetirizine from the novel vesicular delivery system. Further, therapeutic efficacy of optimized formulation was assessed against oxazolone-induced atopic dermatitis in mice. It was observed that the developed formulation was highly efficacious in reducing the itching score (4.75 itches per 20 min) compared to conventional cream (9.75 itches per 20 min) with profound reduction in dermal eosinophil count and erythema score. To conclude, a novel vesicular, dermally safe, and nontoxic topical formulation of cetirizine was successfully developed and may be used to treat atopic dermatitis after clinical investigation.

Preparation and in vivo evaluation of solid lipid nanoparticles of griseofulvin for dermal use.

Griseofulvin-loaded solid lipid nanoparticles (SLNs) were prepared by hot microemulsion technique and optimized for type and concentration of lipid and surfactant. The optimized SLN composition was characterized in terms of particle shape and size, drug entrapment efficiency, pH, stability, spreadability, ex-vivo skin permeation, dermatokinetics, skin sensitivity, in vitro antifungal assay and in vivo antifungal activity against Microsporum canis using guinea pig model for dermatophytosis. The cumulative amount of drug permeated through excised mice skin from SLNs was more than 5-folds as compared to permeation from conventional cream base. Fluorescent microscopy revealed presence of nanoparticles in the skin layers suggesting the penetration of nanoparticles into the skin owing to their nano-size and thence a controlled drug release. A complete mycological and clinical cure was observed in M. canis infected guinea pigs after twice daily application of SLN gel containing griseofulvin for 8 days. Also, the formulation was observed to be non-sensitizing, histopathologically safe, and SLN gel was stable at 5 +/- 3 degrees C, 25 +/- 2 degrees C and 40 +/- 2 degrees C for a period of six months. It can be concluded from our study that SLNs provide a good skin permeation effect and may be a promising carrier for topical delivery of griseofulvin.

Formulation, characterization and evaluation of an optimized microemulsion formulation of griseofulvin for topical application.

The main objective of the study was to develop a microemulsion (ME) formulation of griseofulvin for the treatment of dermatophytosis (Indian Patent Application 208/DEL/2009). The oil phase was selected on the basis of drug solubility whereas the surfactant and cosurfactant were screened on the basis of their oil solubilizing capacity as well as their efficiency to form ME from pseudo-ternary phase diagrams. The influence of surfactant and cosurfactant mass ratio (Smix) on the ME formation and its permeation through male Laca mice skin was studied. The optimized formulation (ME V) consisting of 0.2% (w/w) griseofulvin, 5% (w/w) oleic acid, 40% (w/w) Smix (1:1, Tween 80 and ethanol) possessed globule size of 12.21 nm, polydispersity index of 0.109 and zeta potential value of -0.139 mV. ME V exhibited 7, 5 and almost 3-fold higher drug permeation as compared to aqueous suspension, oily solution and conventional cream respectively. Besides this the formulation was also evaluated for drug content, pH, stability, dermatopharmacokinetics and antifungal activity against Microsporum canis using guinea pig model for dermatophytosis. Treatment of guinea pigs with ME V resulted in a complete clinical and mycological cure in 7 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5±3°C, 25±2°C and 40±2°C for a period of six months.

Preparation and evaluation of antifungal efficacy of griseofulvin loaded deformable membrane vesicles in optimized guinea pig model of Microsporum canis--dermatophytosis.

The present study is aimed at the encapsulation of griseofulvin in the deformable membrane vesicles (DMVs) for dermal delivery. Presently, griseofulvin is available only in conventional oral dosage forms that suffer from the issues of poor and highly variable bioavailability, numerous systemic side effects and long duration of treatment. Multi-lamellar drug-loaded DMVs of griseofulvin (Indian Patent Application 208/DEL/2009) were prepared by thin-film hydration method and were optimized for type and concentration of edge activator (EA). The optimized formulation was evaluated for vesicular shape, size, drug entrapment efficiency, drug content, pH, stability, spreadability, ex vivo skin permeation, dermatokinetics, skin sensitivity, in vitro antifungal assay and in vivo antifungal activity against Microsporum canis using guinea pig model for dermatophytosis. The optimized DMVs illustrated remarkably higher drug permeation and skin retention when compared with liposomes. A complete clinical and mycological cure was observed in animals treated with topical griseofulvin formulation in 10 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5±3 °C, 25±2 °C and 40±2 °C for a period of six months. The results indicated that the topical formulation of DMVs of griseofulvin could be utilized as an alternative to reduce the encumbrance of conventional oral formulations.

Preparation and evaluation of dermal delivery system of griseofulvin containing vitamin E-TPGS as penetration enhancer.

Griseofulvin, an antifungal agent, is a BCS class II drug slowly, erratically, and incompletely absorbed from the gastrointestinal tract in humans. The clinical failure of the conventional oral therapy of griseofulvin is most likely attributed to its poor solubility and appreciable inter- and intra-subject variation in bioavailability from different commercial products. Moreover, the conventional oral therapy is associated with numerous adverse effects and interactions with other drugs. The purpose of the study was to formulate a topical application of griseofulvin which would deliver the drug locally in a therapeutically effective concentration. Griseofulvin was solubilized in ethanol, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and combinations of ethanol with varying amounts of TPGS; then, it was incorporated in the Carbopol (980 NF) base. The formulations were characterized and evaluated ex vivo using Laca mice skin, microbiologically against Microsporum gypseum and Microsporum canis and clinically in a small group of patients. The current study suggested that TPGS and ethanol synergistically enhanced the drug permeation and drug retention in the skin. The selected formulation F VII was found to be effective against M. gypseum and M. canis, non-sensitizing, histopathologically safe, stable at 4°C, 25°C, and 40°C with respect to percent drug content, permeation characteristics, pH, transparency, feel, viscosity, and clinically effective in a small group of subjects. The proposed topical formulation of griseofulvin may be an effective and convenient alternative to the currently available oral therapy for the treatment of superficial fungal infections.