ABSTRACT
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.
Subject(s)
Acyclovir/administration & dosage , Antifungal Agents/administration & dosage , Antiviral Agents/administration & dosage , Drug Carriers , Fatty Acids/chemistry , Ketoconazole/administration & dosage , Acyclovir/chemistry , Administration, Cutaneous , Antifungal Agents/chemistry , Antiviral Agents/chemistry , Diffusion , Drug Compounding , Drug Stability , Drug Storage , Female , Gels , Humans , Hydrogen-Ion Concentration , In Vitro Techniques , Ketoconazole/chemistry , Nitrous Oxide/chemistry , Ointments , Particle Size , Skin/metabolism , Skin Absorption , Solubility , Technology, Pharmaceutical/methods , ViscosityABSTRACT
Currently, macromolecular drugs such as proteins are mainly administered by means of injections due to their low intestinal epithelial permeability and poor stability in the gastrointestinal tract. This study investigated binary combinations of chemical drug absorption enhancers to determine if synergistic drug absorption enhancement effects exist. Aloe vera, Aloe ferox and Aloe marlothii leaf gel materials, as well as with N-trimethyl chitosan chloride (TMC), were combined in different ratios and their effects on the transepithelial electrical resistance (TEER), as well as the transport of FITC-dextran across Caco-2 cell monolayers, were measured. The isobole method was applied to determine the type of interaction that exists between the absorption enhancers combinations. The TEER results showed synergism existed for the combinations between A. vera and A. marlothii, A. marlothii and A. ferox as well as A. vera and TMC. Antagonism interactions also occurred and can probably be explained by chemical reactions between the chemical permeation enhancers, such as complex formation. In terms of FITC-dextran transport, synergism was found for combinations between A. vera and A. marlothii, A. marlothii and A. ferox, A. vera and TMC, A. ferox and TMC and A. marlothii and TMC, whereas antagonism was observed for A. vera and A. ferox. The combinations where synergism was obtained have the potential to be used as effective drug absorption enhancers at lower concentrations compared to the single components.
