No abstract

The skin is the largest organ of the integumentary system with a multifunctional purpose to protect the body from heat and microbes, regulate body temperature, and act as a sensory organ. A topical dosage form applied on the skin will have to cross the stratum corneum, which would then allow the dosage form to traverse the subsequent layers of the skin. The drug with poor solubility and short half-life would serve as an ideal candidate for its delivery via the transdermal route. This review reports the role of natural oils in enhancing the permeation of drugs through skin as they possess different features like natural origin, favorable penetration enhancement, and partitioning action in the skin. Chemical penetration enhancers have been used widely but are associated with toxicities. Thus, more research should be channelized in the area of extraction of oils from natural sources, along with their active constituents, which can serve as therapeutic alternatives to various disorders and diseases. Natural oils are obtained from leaves, fruits, flowers, seeds, bark, and roots, which have a therapeutic potential as well as penetration enhancing activity. The demerits of oral drug delivery include degradation of drugs in the gastrointestinal tract, addition of taste masking, and coating of tablets, which can be overcome by delivering the drug via the transdermal route. Natural oil contains lipids, flavonoids, and terpenes, which play a significant role in anti-inflammatory and penetration enhancing activity.

Background Onychomycosis is an opportunistic fungal infection often infecting people with compromised immune system. Currently available treatment interventions such as physical, surgical, and chemical‐based approaches are successful in treating the condition, however, are painful and nonpatient complaint. Moreover, dermal creams with antifungal agents do not penetrate nail plate as required; hence, there is a necessity of developing a novel formulation with enhanced penetration. Aims The aim of the present research work was to develop ketoconazole microemulsion‐loaded hydrogel formulation containing nigella oil as permeation enhancer for the treatment of onychomycosis. Methods Screening of oils, surfactants, and cosurfactants were done based on solubility studies followed by the construction of pseudo‐ternary phase diagrams with 2% ketoconazole. The microemulsion was characterized for globule size, zeta potential, viscosity, and thermodynamic stability. Ex‐vivo studies were carried out using Franz diffusion cells using porcine skin membrane. The antifungal activity of microemulsion‐loaded hydrogel was evaluated using cup plate method using Candida albicans and Aspergillus niger. Results The optimized microemulsion had a composition of 54.97% Capryol:Nigella (2:1), 36.07% Transcutol:Propylene glycol (2:1), and 7.13% water and was later incorporated into polymeric gel base. The microemulsion‐loaded hydrogel exhibited a 10 hours sustained release profile as compared to the marketed cream and an enhanced activity against marketed ketoconazole cream and compared with marketed ketoconazole formulation. Conclusion The thermodynamic stability, sustained drug release with greater permeation, and enhanced activity due to the presence of nigella oil in microemulsion‐loaded hydrogel warrant its application as an excellent vehicle for treating fungal infections.

Irbesartan (IB) is a water insoluble drug belonging to BCS II that exerts its anti-hypertensive effect through the blockage of angiotensin II receptors. The aqueous insolubility of IB limits its bioavailability and overall efficacy. Hydrotrophy, a solubilization technique to achieve an augmentation in aqueous solubility of poorly water-soluble drugs, has recently gained a lot of interest due to its safety, economics, and use of non-toxic and non-flammable adjuvants. The present study deals with application of hydrotrophy techniques to increase the solubility of IB using sodium benzoate and urea as the hydrotropic agent. The results showed a significant enhancement in dissolution profile of IB as compared to non-hydrotropic drug. The dissolution rate and solubility comparison of both hydrotropic agents revealed that sodium benzoate has a better solubilizing efficiency than urea. Hence, it can be concluded that hydrotropic concept can be adopted as a solubility enhancement technique for poorly water-soluble drugs.