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.     

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.     

Optimization and evaluation of pluronic lecithin organogels as a transdermal delivery vehicle for sinomenine

The purpose of the present study was to prepare and optimize sinomenine (SIN) pluronic lecithin organogels system (PLO), and to evaluate the permeability of the optimized PLO in vitro and in vivo. Box–Behnken design was used to optimize the PLO and the optimized formulation was pluronic F127 of 19.61%, lecithin of 3.60% and SIN of 1.27%. The formulation was evaluated its skin permeation and drug deposition both in vitro and in vivo compared with gel. Permeation and deposition studies of PLO were carried out with Franz diffusion cells in vitro and with microdialysis in vivo. In vitro studies, permeation rate (J_ss) of SIN from PLO was 146.55?±?2.93?μg/cm²/h, significantly higher than that of gel (120.39?μg/cm²/h) and the amount of SIN deposited in skin from the PLO was 10.08?±?0.86?μg/cm², significantly larger than that from gel (6.01?±?0.04?μg/cm²). In vivo skin microdialysis studies showed that the maximum concentration (C_max) of SIN from PLO in “permeation study” and “drug-deposition study” were 150.27?±?20.85?μg/ml and 67.95?μg/ml, respectively, both significantly higher than that of SIN from gel (29.66 and 6.73?μg/ml). The results recommend that PLO can be used as an advantageous transdermal delivery vehicle to enhance the permeation and skin deposition of SIN.     

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.     

An evaluation of crude palm oil (CPO) and tocotrienol rich fraction (TRF) of palm oil as percutaneous permeation enhancers using full-thickness human skin

The drawbacks associated with chemical skin permeation enhancers such as skin irritation and toxicity necessitated the research to focus on potential permeation enhancers with a perceived lower toxicity. Crude palm oil (CPO) is obtained by direct compression of the mesocarp of the fruit of the oil palm belonging to the genus Elaeis. In this research, CPO and tocotrienol-rich fraction (TRF) of palm oil were evaluated for the first time as skin permeation enhancers using full-thickness human skin. The in vitro permeation experiments were conducted using excised human skin mounted in static upright ‘Franz-type’ diffusion cells. The drugs selected to evaluate the enhancing effects of these palm oil derivatives were 5-fluorouracil, lidocaine and ibuprofen: compounds covering a wide range of Log p values. It was demonstrated that CPO and TRF were capable of enhancing the percutaneous permeation of drugs across full-thickness human skin in vitro. Both TRF and CPO were shown to significantly enhance the permeation of ibuprofen with flux values of 30.6?µg/cm² h and 23.0?µg/cm² h respectively, compared to the control with a flux of 16.2?µg/cm² h. The outcome of this research opens further scope for investigation on the transdermal penetration enhancement activity of pure compounds derived from palm oil.     

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.     

Solid lipid micro-dispersions (SLMs) based on PEGylated solidified reverse micellar solutions (SRMS): a novel carrier system for gentamicin

Abstract

The purpose of this study was to formulate and evaluate novel PEGylated solidified reverse micellar solutions (SRMS)-based solid lipid microparticles (SLMs) for improved delivery of gentamicin. Lipid matrix (SRMS) [consisting of 15% w/w Phospholipon® 90G (P90G) in 35% w/w dika wax (Irvingia gabonensis) was formulated and characterized by differential scanning calorimetry (DSC). SLMs were formulated by melt-emulsification using the SRMS, PEG 4000 and gentamicin (1.0, 2.0, 3.0% w/w), and their physicochemical as well as pharmacokinetic parameters determined. In vitro permeation of gentamicin from the SLMs through artificial membrane (0.22?μm pore size) was carried out using Franz’s cell and phosphate-buffered saline (PBS, pH 7.4) as acceptor medium, while bioevaluation was performed using clinical isolates of Pseudomonas aeruginosa and Staphylococcus aureus. Stable and irregularly-shaped gentamicin-loaded SLMs of size range 34.49?±?2.56 to 53.52?±?3.09?µm were obtained. The SLMs showed sustained drug permeation and exhibited time-dependent and capacity-limited bioactivity. Overall, SLMs containing 2% w/w SRMS, 3% w/w gentamicin and PEG 4000 entrapped the highest amount of drug, gave highest IZD against the test organisms and highest permeation flux (5.239?μg/cm².min) and permeation coefficient (1.781?×?10^?6?cm/min) within 420?min, while pure gentamicin gave the least. Preliminary in vivo pharmacokinetic studies also showed an AUC-₂₄ of 1507?µg/h/ml for the optimized formulation, while that of oral drug solution was 678?µg/h/ml. This showed a 2.2-fold increase in the systemic bioavailability of gentamicin from the optimized formulation. PEGylated SRMS-based SLMs prepared with heterolipid from Irvingia gabonensis would likely offer a reliable delivery system for gentamicin.     

Buccal films of prednisolone with enhanced bioavailability

Abstract

The conventional formulation of prednisolone is considered to be low in efficacy, primarily on account of their failure in providing and maintaining effective therapeutic drug levels. This study aims to focus on development of a mucoadhesive buccal delivery system with a twofold objective of offering a rapid as well as a prolonged delivery of prednisolone coupled with enhanced therapeutic efficacy. Buccoadhesive films of prednisolone were prepared by solvent-casting method using hydroxyl propyl methyl cellulose (K100), Carbopol 940 and/or Eudragit® NE 40?D. Placebo films possessing the most desirable physicomechanical properties were selected for drug loading. The effect of polymer and its content on film properties, i.e. mucoadhesive strength, swelling and hydration, in vitro drug release was studied. Based on these studies, film F7D was selected for ex vivo permeation across porcine cheek mucosa. The steady state flux of prednisolone across the buccal mucosa was found to be 105.33?±?32.07?µg/cm²/h. A comparative pharmacokinetic study of prepared film (F7D) and oral suspension of prednisolone was conducted. In vivo data of buccal film show greater bioavailability (AUC_0–α: 24.26?±?4.06?µg.h/ml versus 10.65?±?2.15?µg.h/ml) and higher C_max (2.70?±?0.38?µg/ml versus 2.29?±?0.32?µg/ml) value when compared to oral suspension. The data observed from this study highlight the feasibility of the buccal route as a viable option for delivery of prednisolone.     

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.     

Evaluation of progesterone permeability from supercritical fluid processed dispersion systems

Abstract

The aim of this study was to investigate the permeability of unique dispersion systems prepared by supercritical fluid (SCF) processing, to deliver bioidentical progesterone (PGN) across mouse skin. Semisolid dispersions of PGN were made up of either polyethylene glycol (PEG) 400/4000, Gelucire 44/14, d-α-tocopheryl PEG 1000 succinate (TPGS), tanscutol P or myritol 318. SCF dispersion systems were compared with various control formulations; a market cream, aqueous suspension, and three conventionally prepared dispersions comelted, cosolvent and physically mixed systems. The permeability coefficient in the absence or presence of a permeation enhancer was evaluated using ex vivo mouse skin. The permeation study results for the TPGS/myritol/transcutol P dispersion system prepared using supercritical carbon dioxide (SC-CO₂) had a two-fold improvement in transdermal permeation over 24?h compared to the control formulation, 245.7 and 126?µg?cm^?2, respectively (p value?<?0.05). In this study, the skin integrity and morphology was also investigated for changes due to the formulation constituents using histological examination and Fourier transform infrared spectroscopy. The particles from the gas-saturated suspension method and SC-CO₂ together with TPGS/myritol/transcutol P may offer potential advantages over the available cream on the market based on the vastly improved lag time and flux of PGN across the skin.     

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.     

Formulation and characterization of Phospholipon 90 G and tween 80 based transfersomes for transdermal delivery of eprosartan mesylate

The objective of the current study was to formulate the eprosartan mesylate loaded transfersomes using different proportions of Phospholipon^® 90?G and Tween^® 80 (95–75:5–25% w/w). The prepared transfersomes were characterized for their vesicles size, shape, polydispersity index, zeta potential, entrapment efficiency, in vitro skin permeation, confocal laser scanning microscopy, and in vivo skin irritation. Results revealed that the formulated transfersomes were negatively charged, spherical unilamellar structure of 71.18–85.66?nm with entrapment efficiency of 83.00–88.19%, and presented transdermal flux of 1.78–5.02?μg/cm²/h across rat skin. Confocal laser scanning microscopy confirmed that the formulated rhodamine 6?G loaded transfersomes could penetrate deeply and uniformly into rat skin. Additionally, in vivo skin irritation studies revealed that the prepared transfersomes were devoid of any skin irritation potential (erythema and edema). Results of this study revealed that the transfersomes prepared with Tween^® 80 could be used to enhance the transdermal delivery of eprosartan mesylate. In conclusion, transdermal transfersomes formulation may prove to be an encouraging drug carrier for eprosartan mesylate and other actives, particularly owing to their simple formulation and unsophisticated scale-up methods.     

Neuroprotective study of Nigella sativa-loaded oral provesicular lipid formulation: in vitro and ex vivo study

Abstract

Aim: The aim of this research was to develop proniosome (niosomes) of Nigella sativa (NS) to improve its drug release, gastrointestinal (GI) permeation and neuroprotective activity.

Materials and methods: Proniosomes were prepared by thin film method using various compositions of nonionic surfactants, cholesterol, and phosphatidylcholine. The optimum influence of different formulation variables of NS such as surfactant type, phosphatidylcholine and cholesterol concentration were optimized for size and entrapment efficiency.

Results and discussion: Results indicated that prepared niosome showed smaller size with high entrapment efficiency. The permeation enhancement ratio was found to be 2.16 in comparison to control with maximum flux value obtained was 7.23?µg/cm²/h for formulation NS6. The in vivo study revealed that the niosomal dispersion significantly improved neuroprotective activity in comparison to standard and control formulation.

Conclusion: In conclusion, developed proniosomal formulation could be one of the promising delivery system for NS with better drug release and GI permeation profiles and improved neuroprotective activity and merits for further study.     

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.     

Nanostructured lipid carriers of pioglitazone for transdermal application: from experimental design to bioactivity detail

Abstract

Pioglitazone (PZ) an anti-hyperglycemic agent is used in the treatment of type 2 diabetes. The aim of this study was to design PZ-loaded nanostructured lipid carriers (NLC) to investigate the bioavailability improvement by transdermal delivery. PZ NLCs were prepared using high-pressure homogenization followed by ultrasonication. The NLCs were evaluated for particle size analysis, drug loading, ex vivo skin transport studies and in vivo bioactivity study. The prepared NLCs had a mean size of 166.05?nm and drug loading of 10.41% with flux value of 47.36?µg/cm²/h. The entrapment of PZ is >70% in the NLCs with enhancement ratio of 3.2 times. The in vivo pharmacokinetic study showed 2.17 times enhancement in bioavailability study and pharmacodynamics study showed that PZ NLC-based transdermal therapeutic system (PNLG-TTS) lowers blood sugar level in a sustained pattern for a prolonged period of time as compared to Piosys tablet (marketed). The shelf life of the optimized formulation was found to be 1.83?years. These results clearly provide a lead that above NLCs-based TTS is potential controlled release formulation for PZ and could be a promising drug delivery system for the treatment of diabetes.     

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.     

Novel Biomaterial for Transdermal Application: In vitro and In vivo Characterization

The objective of the present study was to evaluate a novel film forming biomaterial for its potential application in the preparation of unilaminate transdermal adhesive matrix systems. The biomaterial, Damar Batu (DB), was tried alone and in combination with Eudragit RL100 as a matrixing agent in the preparation of transdermal patches. Developed transdermal patches of Diltiazem hydrochloride (DH) were evaluated for thickness uniformity, weight uniformity, folding endurance and drug content. USP dissolution apparatus V was used for in vitro drug release studies. Modified Franz diffusion cell used for permeation study using excised human cadaver skin. Total 6 formulations were developed and on the basis of in vitro drug release and in vitro skin permeation profile F5 composed of DB: Eudragit RL100 (60:40) and carrying 20 %w/w DH was selected as an optimized formulation for in vivo study. The in vivo study results showed that F5 achieved the Cmax of about 269.76?±?1.52?ng/mL in 6?h and sustained the release of the drug till 24?h. The skin irritation study results proved that the novel biomaterial is non-sensitizing and non-irritating. Drug-polymer interaction study carried out to check the compatibility of drug and polymer showed the intactness of the drug in the formulation proving the compatibility of the polymer. It can be proposed from the outcome of the present study that by applying suitable adhesive layer and backing membrane, DB: Eudragit RL100 (60:40) transdermal patches can be of potential therapeutic use.     

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.     

Effect of microneedle treatment on the skin permeation of a nanoencapsulated dye

Objectives The aim of the study was to investigate the effect of microneedle (MN) pretreatment on the transdermal delivery of a model drug (Rhodamine B, Rh B) encapsulated in polylactic‐co‐glycolic acid (PLGA) nanoparticles (NPs) focusing on the MN characteristics and application variables. Methods Gantrez MNs were fabricated using laser‐engineered silicone micro‐mould templates. PLGA NPs were prepared using a modified emulsion–diffusion–evaporation method and characterised in vitro. Permeation of encapsulated Rh B through MN‐treated full thickness porcine skin was performed using Franz diffusion cells with appropriate controls. Key findings In‐vitro skin permeation of the nanoencapsulated Rh B (6.19 ± 0.77 µg/cm²/h) was significantly higher (P < 0.05) compared with the free solution (1.66 ± 0.53 µg/cm²/h). Mechanistic insights were supportive of preferential and rapid deposition of NPs in the MN‐created microconduits, resulting in accelerated dye permeation. Variables such as MN array configuration and application mode were shown to affect transdermal delivery of the nanoencapsulated dye. Conclusions This dual MN/NP‐mediated approach offers potential for both the dermal and transdermal delivery of therapeutic agents with poor passive diffusion characteristics.     

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.