Preparation and Evaluation of Dermal Delivery System of Griseofulvin Containing Vitamin E-TPGS as Penetration Enhancer

摘要

Griseofulvin, an antifungal agent, is a BCS class II drug slowly, erratically, and incompletely absorbed from the gastrointestinal tract in humans. The clinical failure of the conventional oral therapy of griseofulvin is most likely attributed to its poor solubility and appreciable inter- and intra-subject variation in bioavailability from different commercial products. Moreover, the conventional oral therapy is associated with numerous adverse effects and interactions with other drugs. The purpose of the study was to formulate a topical application of griseofulvin which would deliver the drug locally in a therapeutically effective concentration. Griseofulvin was solubilized in ethanol, d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and combinations of ethanol with varying amounts of TPGS; then, it was incorporated in the Carbopol (980 NF) base. The formulations were characterized and evaluated ex vivo using Laca mice skin, microbiologically against Microsporum gypseum and Microsporum canis and clinically in a small group of patients. The current study suggested that TPGS and ethanol synergistically enhanced the drug permeation and drug retention in the skin. The selected formulation F VII was found to be effective against M. gypseum and M. canis, non-sensitizing, histopathologically safe, stable at 4°C, 25°C, and 40°C with respect to percent drug content, permeation characteristics, pH, transparency, feel, viscosity, and clinically effective in a small group of subjects. The proposed topical formulation of griseofulvin may be an effective and convenient alternative to the currently available oral therapy for the treatment of superficial fungal infections.