Context: Viral and fungal cutaneous manifestations are regularly encountered in immunocompromised human immunodeficiency virus/acquired immunodeficiency syndrome individuals and can be treated by drugs such as acyclovir and ketoconazole, respectively.
Objective: The aim of this study was to determine whether the novel Pheroid delivery system improved the transdermal delivery and/or dermal delivery of acyclovir and ketoconazole when incorporated into semi-solid formulations.
Materials and methods: Semi-solid products (creams and emulgels) containing these drug compounds were formulated, either with or without (control) the Pheroid delivery system. The stability of the formulated semi-solid products was examined over a period of six months and included the assay of the actives, pH, viscosity, mass loss and particle size observation. Vertical Franz cell diffusion studies and tape stripping methods were used to determine the in vitro, stratum corneum (SC)-epidermis and epidermis-dermis delivery of these formulations.
Results and discussion: Stability tests showed that none of the formulations were completely stable. Acyclovir showed a biphasic character during the in vitro skin diffusion studies for all the tested formulations. The Pheroid™ cream enhanced the transdermal, SC-epidermis and epidermis-dermis delivery of acyclovir the most. The average amount of ketoconazole diffused over 12 h showed improved delivery of ketoconazole, with the Pheroid™ emulgel exhibiting the best transdermal and epidermis-dermis delivery.
Conclusion: The Pheroid formulae increased transdermal penetration as well as delivery to the dermal and epidermal skin layers. The Pheroid emulgel and the Pheroid cream increased the topical delivery of ketoconazole and acyclovir, respectively.
Keywords: Franz cell; Pheroid; stability; tape stripping; topical delivery.