Hyperbranched dendritic nano-carriers for topical delivery of dithranol

Abstract

The purpose of the current investigation was to explore the potential of polypropylene imine (PPI) dendrimers to deliver dithranol (DIT) topically and to evaluate its encapsulation, permeation and skin irritation potential. PPI (5.0 generation, 5.0?G) dendrimers and DIT-loaded PPI (DIT–PPI) were prepared and characterized by spectroscopy and transmission electron microscopy. DIT encapsulation, in vitro skin permeation study, skin irritation studies, fluorescent studies and tape stripping studies were performed. Loading of DIT was found to be pH dependent with maximum encapsulation at acidic pH (1.0?±?0.02, 17.2?±?0.56 and 57.1?±?1.32% at 7.4, 5.5 and 1.2 pH, respectively). DIT–PPI showed significantly enhanced permeation rate constant and lesser skin irritation (11.61?±?1.80?μg/cm²/h and 1.0, respectively) when compared with the plain DIT solution (2.72?±?0.31?μg/cm²/h and 2.3, respectively). Skin separation studies and confocal laser scanning microscope images showed that the dye-loaded dendrimers exhibits deposition of dye in pilosebaceous compartment. These studies demonstrate that PPI can be exploited to improve the topical bioavailability of the molecules in a controlled pattern. The enhanced accumulation of DIT via dendrimer carrier within the skin might help optimize targeting of this drug to the epidermal and dermal sites, thus creating new opportunities for well-controlled, modern topical application of DIT for the treatment of psoriasis.     

Formulation and optimization of nanoemulsion using antifungal lipid and surfactant for accentuated topical delivery of Amphotericin B

The objective of the study was to develop, optimize and evaluate a nanoemulsion (NE) of Amphotericin B (AmB) using excipients with inherent antifungal activities (Candida albicans and Aspergillus niger) for topical delivery. AmB-loaded NE was prepared using Capmul PG8 (CPG8), labrasol and polyethylene glycol-400 by spontaneous titration method and evaluated for mean particle size, polydispersity index, zeta potential and zone of inhibition (ZOI). NE6 composed of CPG8 (15%w/w), S_mix (24%w/w) and water (61%w/w) was finally selected as optimized NE. AmB-NE6 was studied for improved in vitro release, ex vivo skin permeation and deposition using the Franz diffusion cell across the rat skin followed with drug penetration using confocal laser scanning microscopy (CLSM) as compared to drug solution (DS) and commercial Fungisome^®. The results of in vitro studies exhibited the maximum ZOI value of NE6 as 19.1?±?1.4 and 22.8?±?2.0?mm against A. niger and C. albicans, respectively, along with desired globular size (49.5?±?1.5?nm), zeta potential (?24.59?mV) and spherical morphology. AmB-NE6 revealed slow and sustained release of AmB as compared to DS in buffer solution (pH 7.4). Furthermore, AmB-NE6 elicited the highest flux rate (22.88?±?1.7?μg/cm²/h) as compared to DS (2.7?±?0.02?μg/cm²/h) and Fungisome^® (11.5?±?1.0?μg/cm²/h). Moreover, the enhancement ratio and drug deposition were found to be highest in AmB-NE6 than DS across the stratum corneum barrier. Finally, CLSM results corroborated enhanced penetration of the AmB-NE6 across the skin as compared to Fungisome^® and DS suggesting an efficient, stable and sustained topical delivery.     

Elastic Liposomal Formulation for Sustained Delivery of Colchicine: In Vitro Characterization and In Vivo Evaluation of Anti-gout Activity

Colchicine, an alkaloid found in extracts of the plants Colchicum autumnale and Gloriosa superb, is effective in the treatment of acute gout and dermatological conditions like leuko-cytoclastic vasculitis, psoriasis, and Sweet’s syndrome. Oral administration of colchicine is associated with gastrointestinal side effects and its accumulation in the body leads to bone marrow suppression. In the present study, an attempt has been made for development and in vitro and in vivo evaluation of elastic liposomal formulation for topical delivery of colchicine. The in vitro skin permeation study across rat skin found transdermal flux for different elastic liposomal formulations to range between 32.8?±?1.2 and 44.4?±?1.9 μg h^?1 cm^?2, which was approximately seven to 11 times higher than obtained using drug solution (4.3?±?0.6 μg h^?1 cm^?2). The results of skin deposition study showed that elastic liposomal formulation provide 12.5-fold higher skin deposition as compared to drug solution of colchicine. Confocal laser scanning microscopy also revealed better accumulation and deeper penetration (up to 200 μm) of elastic liposomes than drug solution (up to 12 μm). The biological evaluation of various vesicular formulations and drug solution was carried out using monosodium urate-induced air pouch model. The results of anti-gout activity in rats showed better and sustained biological effects in 24 h measured in terms of exudate volume (63.1?±?5.7% and 9.6?±?0.5% reduction with elastic liposomes and drug solution, respectively), reduction in leukocyte count (74.2?±?6.0% and 4.1?±?0.3% reduction with elastic liposomes and drug solution, respectively), decrease in inflammatory cells accumulation, and collagen deposition with elastic liposomal formulation than drug solution. Hence, the present study reveals that elastic liposomal formulation of colchicine possesses greater potential to enhance skin accumulation, prolong drug release, and improve the site-specificity of colchicine.     

Nanoemulsion gel-based topical delivery of an antifungal drug: in vitro activity and in vivo evaluation

Abstract

Objective: In this study, attempt has been focused to prepare a nanoemulsion (NE) gel for topical delivery of amphotericin B (AmB) for enhanced as well as sustained skin permeation, in vitro antifungal activity and in vivo toxicity assessment.

Materials and methods: A series of NE were prepared using sefsol-218 oil, Tween 80 and Transcutol-P by slow spontaneous titration method. Carbopol gel (0.5%?w/w) was prepared containing 0.1%?w/w AmB. Furthermore, NE gel (AmB-NE gel) was characterized for size, charge, pH, rheological behavior, drug release profile, skin permeability, hemolytic studies and ex vivo rat skin interaction with rat skin using differential scanning calorimeter. The drug permeability and skin irritation ability were examined with confocal laser scanning microscopy and Draize test, respectively. The in vitro antifungal activity was investigated against three fungal strains using the well agar diffusion method. Histopathological assessment was performed in rats to investigate their toxicological potential.

Results and discussion: The AmB-NE gel (18.09?±?0.6?µg/cm²/h) and NE (15.74?±?0.4?µg/cm²/h) demonstrated the highest skin percutaneous permeation flux rate as compared to drug solution (4.59?±?0.01?µg/cm²/h) suggesting better alternative to painful and nephrotoxic intravenous administration. Hemolytic and histopathological results revealed safe delivery of the drug. Based on combined results, NE and AmB-NE gel could be considered as an efficient, stable and safe carrier for enhanced and sustained topical delivery for AmB in local skin fungal infection.

Conclusion: Topical delivery of AmB is suitable delivery system in NE gel carrier for skin fungal infection.     

Investigation of true nanoemulsions for transdermal potential of indomethacin: characterization,rheological characteristics,and ex vivo skin permeation studies

The aim of the present study was to investigate the potential of true nanoemulsions for transdermal delivery of indomethacin. Thermodynamically stable true nanoemulsions were characterized for morphology using transmission electron microscopy (TEM), droplet size, rheological characteristics, and refractive index. The rheological behavior for all true nanoemulsions was found to be Newtonian as viscosity was unchanged by increasing the rate of shear. The ex vivo skin permeation studies were performed using Franz diffusion cell with rat skin as permeation membrane. The ex vivo skin permeation profile of optimized formulation was compared with marketed Indobene gel and nanoemulsion gel. Significant increase in permeability parameters was observed in nanoemulsion formulations (P?<?0.05). The steady-state flux (J_ss) and permeability coefficient (K_p) for optimized nanoemulsion formulation were found to be 73.96?±?2.89?μg/cm²/h and 1.479?×?10^?2?±?0.289?×?10^??2?cm/h, respectively, which were significant compared with Indobene gel and nanoemulsion gel (P?<?0.05). Enhancement ratio (E_r) was found to be 7.88 in optimized formulation F6 compared with other formulations. These results suggested that nanoemulsions can be used as potential vehicles for improved transdermal delivery of indomethacin.     

Novel non-ionic surfactant proniosomes for transdermal delivery of lacidipine: optimization using 23 factorial design and in vivo evaluation in rabbits

Abstract

Context: Proniosomes offer a versatile vesicle drug delivery concept with potential for delivery of drugs via transdermal route.

Objectives: To develop proniosomal gel using cremophor RH 40 as non-ionic surfactant containing the antihypertensive drug lacidipine for transdermal delivery so as to avoid its extensive first pass metabolism and to improve its permeation through the skin.

Materials and methods: Proniosomes containing 1% lacidipine were prepared by the coacervation phase separation method, characterized, and optimized using a 2³ full factorial design to define the optimum conditions to produce proniosomes with high entrapment efficiency, minimal vesicle size, and high-percentage release efficiency. The amount of cholesterol (X₁), the amount of soya lecithin (X₂), and the amount of cremophor RH 40 (X₃) were selected as three independent variables.

Results and discussion: The system F4 was found to fulfill the maximum requisite of an optimum system because it had minimum vesicle size, maximum EE, maximum release efficiency, and maximum desirability. The optimized system (F4) was then converted to proniosomal gel using carbopol 940 (1% w/w). In vitro permeation through excised rabbit skin study revealed higher flux (6.48?±?0.45) for lacidipine from the optimized proniosomal gel when compared with the corresponding emulgel (3.04?±?0.13) mg/cm²/h. The optimized formulation was evaluated for its bioavailability compared with commercial product. Statistical analysis revealed significant increase in AUC (0???α) 464.17?±?113.15?ng h/ml compared with 209.02?±?47.35?ng h/ml for commercial tablet. Skin irritancy and histopathological investigation of rat skin revealed its safety.

Conclusions: Cremophor RH 40 proniosomal gel could be considered as very promising nanocarriers for transdermal delivery of lacidipine.     

Lipid Based nanoformulation of lycopene improves oral delivery: formulation optimization,ex vivo assessment and its efficacy against breast cancer

This study aims at developing an optimised nanostructured lipid carrier (NLC) of lycopene for efficient absorption following oral administration. The optimised formulation showed an average particle size of 121.9?±?3.66?nm, polydispersity index (PDI) 0.370?±?0.97 and zeta potential ?29.0?±?0.83?mV. Encapsulation Efficiency (% EE) and drug loading (% DL) was found to be 84.50%?±?4.38 and 9.54%?±?2.65, respectively. In vitro release studies demonstrated the burst release within 4–9?h followed by sustained release over 48?h. The IC₅₀ value of lycopene extract and optimised NLC for ABTS^+? were found to be 172.37?μg Trolox equivalent and 184.17?μg Trolox equivalent whereas, for DPPH^?, 117.76?μg Trolox equivalent and 143.08?μg Trolox equivalent respectively. Ex vivo studies and MTT assay revealed that the NLC had better permeation and cause sufficiently more cytotoxicity as compared to drug extract due to higher bioavailability and greater penetration.     

Formulation,optimization and evaluation of transferosomal gel for transdermal insulin delivery

The present study deals with the development of transferosomal gel containing insulin by reverse phase evaporation method for painless insulin delivery for use in the treatment of insulin dependent diabetes mellitus. The effect of independent process variables like ratio of lipids (soya lecithin:cholesterol), ratio of lipids and surfactants, and ratio of surfactants (Tween 80:sodium deoxycholate) on the in vitro permeation flux (μg/cm²/h) of formulated transferosomal gels containing insulin through porcine ear skin was optimized using 2³ factorial design. The optimal permeation flux was achieved as 13.50 ± 0.22 μg/cm²/h with drug entrapment efficiency of 56.55 ± 0.37% and average vesicle diameter range, 625–815 nm. The in vitro insulin permeation through porcine ear skin from these transferosomal gel followed zero-order kinetics (R² = 0.9232–0.9989) over a period of 24 h with case-II transport mechanism. The in vitro skin permeation of insulin from optimized transferosomal gel by iontophoretic influence (with 0.5 mA/cm² current supply) also provided further enhancement of permeation flux to 17.60 ± 0.03 μg/cm²/h. The in vivo study of optimized transferosomal gel in alloxan-induced diabetic rat has demonstrated prolonged hypoglycemic effect in diabetic rats over 24 h after transdermal administration.     

High-efficient nano-carrier gel systems for testosterone propionate skin delivery

Abstract

The purpose of the current investigation was to evaluate the skin delivery potential of the different nano-carrier gels including liposomal gel, ethosomal gel and microemulsion gel bearing testosterone propionate (TP) as a testosterone deficient therapy. The prepared nano-particles were characterized for their shape, particle size distribution and zeta potential. In vitro skin permeation and in vivo transdermal delivery of nano-carrier gels were studied with the Franz diffusion cells and confocal laser scanning microscopy (CLSM). The results showed that all of nano-particles were almost spherical with low polydispersity and nano-metric size range from 40 to 200?nm. TP ethosomal gel also provided an enhanced transdermal flux of 7.64?±?1.4?μg/cm²/h and a decreased lag time of 0.69?h across rat skin as compared with the other two formulations. The skin penetration efficiency of TP nano-carrier gels also revealed that TP ethosomal gel would enhanced penetration of rhodamine red (RR)-loaded formulation to the deeper layers of the skin (268?µm) than the liposomal gel (192?µm) and microemulsion gel (228?µm). This study demonstrated TP ethosomal gel is a promising nano-carrier for delivering TP through the skin.     

Effect of non–phospholipid-based cationic and phospholipid-based anionic nanosized emulsions on skin retention and anti-inflammatory activity of celecoxib

Context: Celecoxib (CXB, 0.2?g)-loaded anionic and cationic nanosized emulsions were prepared by a well-established combined emulsification method.

Objectives: To investigate the effect of non–phospholipid-based cationic and phospholipid-based anionic emulsions on skin retention and anti-inflammatory activity of CXB.

Methods: Using Keshary-Chien diffusion cells with cellulose acetate membrane or excised rat skin, in vitro release and skin retention of CXB from solution and emulsions were studied. The anti-inflammatory activity was evaluated by the carrageenan-induced hind paw edema method in Wistar rats.

Results: The amount of drug released through artificial membrane has decreased from 122.00?±?0.70?μg/cm² for the CXB solution to 55.80?±?0.70?μg/cm² for anionic emulsion, and then further decreased to 24.79?±?0.90?μg/cm² for cationic emulsion. The J_SS value obtained with solution, anionic, and cationic emulsions were 6825.79?±?920.86, 2513.15?±?382.71, and 1925.67?±?147.42, respectively. Cationic emulsion showed a significantly higher level (P?≤?0.05) of drug accumulation in full-thickness rat skin than anionic emulsion, and a substantially lesser percentage inhibition of edema values compared with both solution and anionic emulsion.

Discussion and conclusion: Sustained drug release together with increased skin accumulation and simultaneously decreased skin permeation as observed with cationic emulsion should substantiate its suitability as a topical delivery vehicle for CXB.     

Novel carbopol-based transfersomal gel of 5-fluorouracil for skin cancer treatment: in vitro characterization and in vivo study

Abstract

5-fluorouracil (5-Fu) is an antineoplastic drug, topically used for the treatment of actinic keratosis and nonmelanoma skin cancer. It shows poor percutaneous permeation through the conventionally applicable creams and thus inefficient for the treatment of deep-seated skin cancer. In the present article, transfersomal gel containing 5-Fu was investigated for the treatment of skin cancer. Different formulation of tranfersomes was prepared using Tween-80 and Span-80 as edge activators. The vesicles were characterized for particle size, shape, entrapment efficiency, deformability and in vitro skin permeation. Optimized formulation was incorporated into 1% carbopol 940 gel and evaluated for efficacy in the treatment of skin cancer. 5-Fu-loaded transfersomes (TT-2) has the size of 266.9?±?2.04?nm with 69.2?±?0.98% entrapment efficiency and highest deformability index of 27.8?±?1.08. Formulation TT-2 showed maximum skin deposition (81.3%) and comparable transdermal flux of 21.46?µg/cm²?h. The TT-2-loaded gel showed better skin penetration and skin deposition of the drug than the marketed formulation. Composition of the transfersomal gel has been proved nonirritant to the skin. We concluded that the developed 5-Fu-loaded transfersomal gel improves the skin absorption of 5-Fu and provide a better treatment for skin cancer.     

5-Fluorouracil shell-enriched solid lipid nanoparticles (SLN) for effective skin carcinoma treatment

Context: The effective treatment of skin carcinoma is warranted for targeting the chemotherapeutic agents into tumor cells and avoiding unwanted systemic absorption.

Objective: This work was dedicated to the purpose of engineering highly penetrating shell-enriched nanoparticles that were loaded with a hydrophilic chemotherapeutic agent, 5-fluorouracil (5-FU).

Methods: Varying ratios of lecithin and poloxamer188 were used to produce shell-enriched nanoparticles by enabling the formation of reversed micelles within this region of the SLN. The localization of 5-FU within the shell region of the SLN, was confirmed using 5-FU nanogold particles as a tracer. SLN were introduced within sodium carboxy methylcellulose hydrogel, and then applied onto the skin of mice-bearing Ehrlich’s ascites carcinoma. The mice were treated with the gel twice daily for 6 weeks.

Results: The transmission electron microscope (TEM) revealed the formation of uniform nanoparticles, which captured reversed micelles within their shell region. The SLNs’ had particle size that ranged from 137?±?5.5?nm to 800?±?53.6, zeta potential of ?19.70?±?0.40?mV and entrapment efficiency of 47.92?±?2.34%. The diffusion of the drug-loaded SLN (269.37?±?10.92?μg/cm²) was doubled when compared with the free drug (122?±?3.09?μg/cm²) when both diffused through a hydrophobic membrane. SLN-treated mice exhibited reduced inflammatory reactions, with reduced degrees of keratosis, in addition to reduced symptoms of angiogenesis compared to 5-FU-treated mice.

Conclusion: SLN possesses the capacity to be manipulated to entrap and release hydrophilic antitumor drugs with ease.     

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/cm², along with permeation flux (6.30?±?0.09?μg/cm²/h) and skin retention (11.74?±?0.155?μg/cm²) across mice skin. The SLNs of DIF showed significant decrease in fluid volume, granuloma tissue weight, leukocyte count/mm³ 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.     

Lecithin/chitosan nanoparticles for transdermal delivery of melatonin

In this study, the potential of lecithin/chitosan nanoparticles (NPs) as colloidal nanosystem for transdermal melatonin delivery was investigated. Mean diameter and zeta-potential of NPs differing in lecithin type (Lipoid S45 and S100) and chitosan content ranged between 113.7 and 331.5?nm and 4.6 and 31.2?mV, respectively. Melatonin loadings were up to 7.2%. The potential of lecithin/chitosan NPs to enhance transdermal melatonin delivery was investigated by determining the drug flux across dermatomed porcine skin and its skin deposition. Lecithin/chitosan NPs provided 1.3–2.3-fold higher flux compared to melatonin solution. The highest flux, 9.0?±?0.21?µg/cm²/h, was observed for S45 lecithin/chitosan NPs with lecithin/chitosan weight ratio of 20:1. NP possible cytotoxicity in vitro was evaluated using human skin keratinocytes and fibroblasts. It was demonstrated that lecithin/chitosan NPs can be applied to skin cells at concentrations up to 200?µg/mL without inducing plasma membrane damage or cell viability decrease.     

Transdermal iontophoretic delivery of selegiline hydrochloride,in vitro

Transdermal iontophoretic delivery of selegiline hydrochloride (SH) across dermatomed human skin was studied. Electrochemical stability and various factors affecting the skin permeation were investigated. SH was stable under the influence of an electrical field. The permeation of SH was very low by passive delivery (2.29?±?0.05 μg/cm²/h) as compared to iontophoresis at 0.5 mA/cm² (65.10?±?5.04 μg/cm²/h). An increase in drug concentration from 1 to 20?mg/mL increased the iontophoretic flux by 13-fold. Optimal pH and salt (NaCl) concentration for iontophoretic delivery of SH were found to be pH 5 and 100?mM, respectively. Overall, with 20?mg/mL SH and a current density of 0.4 mA/cm², a maximum flux of 305.5?μg/cm²/h was obtained. Based on reported pharmacokinetic parameters, input target delivery rate to achieve effective plasma concentration of SH (2.2?ng/mL) was calculated. With a surface area of 40?cm², iontophoretic delivery can provide six to seven times higher levels of SH than the target delivery rate, which enables lowering of the dose and/or patch surface area. Further in vivo studies will be required to prove the efficacy of ionophoresis for enhanced delivery of SH.     

Formulation and evaluation of novel controlled release of topical pluronic lecithin organogel of mefenamic acid

In the present study, pluronic lecithin based organogels (PLO gels) were formulated as topical carrier for controlled delivery of mefenamic acid. Ten organogel formulations were prepared by a method employing lecithin as lipophilic phase and pluronic F-127 as hydrophilic phase in varying concentrations to study various parameters using in vitro diffusion study and in vivo studies. All formulations were found to be off-white, homogenous, and reluctant to be washed easily and have pH value within the range of 5.56–5.80 which is nonirritant. Polymer concentration increased in formulations of F1 to F5 (lecithin) and F6 to F10 (pluronic) resulted in decrease of the gelation temperature, increase of viscosity and reduction of spreadability of gels having polymer tendency to form rigid 3D network. Organogels with higher viscosity were found to be more stable and retard the drug release from the gel. The formulations of F2 and F3 were selected for kinetic studies and stability studies, as they found to have all physical parameters within acceptable limits, highest percent drug content and exhibited highest drug release in eight hours. The order of drug release from various formulations was found to be F2?>?F3?>?F10?>?F4?>?F1?>?F9?>?F8?>?F5?>?F7?>?F6. The optimized formulation F2 was found to follow zero order rate kinetics showing controlled release of the drug from the formulations. In vivo anti-inflammatory activity of optimized mefenamic acid organogel (F2) against a standard marketed preparation (Volini gel) was found satisfactory and significant.     

Evolution of the percutaneous penetration and distribution of uranyl nitrate as a function of skin-barrier integrity: an in vitro assessment

As recommended by OECD Guidelines, percutaneous penetration studies consider intact skin, but rarely injured skin. Recent years have witnessed a growing concern for these two types of dermal exposure in the industry, particularly in the nuclear industry. The aim of this study was to show that a method based on an in vitro device can be used to realistically assess how skin-barrier alterations caused by occupational accidents can modify the percutaneous penetration and distribution of radionuclides, particularly uranium. Wounds encountered in the nuclear industry (i.e., nitric acid burns and abrasion) were simulated on hairless rat skin. Skin-barrier alterations were characterized by means of a histological study and by measuring transepidermal water loss (TEWL) and skin thickness. The percutaneous penetration of uranyl nitrate through intact or injured skin biopsies was then measured in vitro. The maximum uranium flux values obtained for intact skin, skin abrasion with stratum corneum removal, and skin exposed to 2 N HNO₃, 5 N HNO₃, and 14 N HNO₃ were, respectively, 0.6?±?0.02, 1.2?±?0.03, 1.2?±?0.04, 42.0?±?1.0, and 174.0?±?8.7?ng.cm^?2.h^?1. These results demonstrated that the percutaneous absorption of uranium increased with the increased impairment of the stratum corneum. TEWL, combined with maximum uranium flux values measured in vitro, yielded a good prediction of the percutaneous penetration of uranium through injured skin, previously observed in vivo. To conclude, this in vitro assay provides a conservative estimate of the percutaneous diffusion of uranium through intact or injured skin, making it a good alternative method for toxicological studies and risk assessments.     

Controlled delivery of ropinirole hydrochloride through skin using modulated iontophoresis and microneedles

Abstract

The objective of this study was to investigate the effect of modulated current application using iontophoresis- and microneedle-mediated delivery on transdermal permeation of ropinirole hydrochloride. AdminPatch® microneedles and microchannels formed by them were characterized by scanning electron microscopy, dye staining and confocal microscopy. In vitro permeation studies were carried out using Franz diffusion cells, and skin extraction was used to quantify drug in underlying skin. Effect of microneedle pore density and ions in donor formulation was studied. Active enhancement techniques, continuous iontophoresis (74.13?±?2.20?µg/cm²) and microneedles (66.97?±?10.39?µg/cm²), significantly increased the permeation of drug with respect to passive delivery (8.25?±?2.41?µg/cm²). Modulated iontophoresis could control the amount of drug delivered at a given time point with the highest flux being 5.12?±?1.70?µg/cm²/h (5–7?h) and 5.99?±?0.81?µg/cm²/h (20–22?h). Combination of modulated iontophoresis and microneedles (46.50?±?6.46?µg/cm²) showed significantly higher delivery of ropinirole hydrochloride compared to modulated iontophoresis alone (84.91?±?9.21?µg/cm²). Modulated iontophoresis can help in maintaining precise control over ropinirole hydrochloride delivery for dose titration in Parkinson’s disease therapy and deliver therapeutic amounts over a suitable patch area and time.     

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

Abstract

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/cm²) and skin retention (20.686?±?0.517?µg/cm²) 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.     

Chemoprevention of skin cancer using low HLB surfactant nanoemulsion of 5-fluorouracil: a preliminary study

Abstract

Oral delivery of 5-fluorouracil (5-FU) is difficult due to its serious adverse effects and extremely low bioavailability. Therefore, the aim of present investigation was to develop and evaluate low HLB surfactant nanoemulsion of 5-FU for topical chemoprevention of skin cancer. Low HLB surfactant nanoemulsions were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized in terms of droplet size distribution, zeta potential, viscosity and refractive index. Selected formulations and control were subjected to in vitro skin permeation studies through rat skin using Franz diffusion cells. Optimized formulation F9 was subjected to stability and in vitro cytotoxic studies on melanoma cell lines. Enhancement ratio was found to be 22.33 in formulation F9 compared with control and other formulations. The values of steady state flux and permeability coefficient for formulation F9 were found to be 206.40?±?14.56?µg?cm^?2?h^?1 and 2.064?×?10^?2?±?0.050?×?10^?2?cm?h^?1, respectively. Optimized formulation F9 was found to be physical stable. In vitro cytotoxicity studies on SK-MEL-5 cancer cells indicated that 5-FU in optimized nanoemulsion is much more efficacious than free 5-FU. From these results, it can be concluded that the developed nanoemulsion might be a promising vehicle for chemoprevention of skin cancer.