Dermatopharmacokinetic and pharmacodynamic evaluation of ethosomes of griseofulvin designed for dermal delivery

The present study is aimed at evaluation of the dermal delivery potential of griseofulvin-loaded ethosomes. Griseofulvin-loaded ethosomes were prepared using "Cold technique'' (Indian Patent Application 208/DEL/2009). The optimized formulation was characterized for vesicular shape and size, drug entrapment efficiency, drug content, pH, stability, and spreadability. Ex vivo skin permeation, dermatopharmacokinetics, and skin sensitivity studies were carried out using male Laca mice. In vivo antifungal activity was assessed against Microsporum canis using guinea pig model for dermatophytosis. The optimized formulation E7 possessing 2 % phospholipid (PL) and 30 % ethanol exhibited the highest drug entrapment (72.94 +/- 0.80 %) and optimum vesicle size (148.5 +/- 0.48 nm). E7 illustrated remarkably higher drug permeation and skin retention when compared with liposomes. Pharmacodynamic studies in guinea pigs induced with M. canis revealed that the dermal fungal infection was completely cured in 8 days upon twice daily topical application of griseofulvin-loaded ethosomes whereas liposomes led to complete cure in 14 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5 +/- 3, 25 +/- 2, and 40 +/- 2 degrees C for a period of 1 year. Results indicated that dermal delivery of griseofulvin employing ethosomes could be a commendable alternative to reduce the bio-burden associated with conventional oral formulations.