Formulation and Evaluation of a Transferosomal Gel of Famciclovir for Transdermal Use

Famciclovir, the drug of choice for cold sores and recurrent genital herpes, has poor oral bioavailability and is associated with numerous side effects. The study aimed to explore the possibility of transdermal application of famciclovir through a transferosome-loaded gelling system to localize the drug at the site of application with improved penetrability, therapeutic effects, and comfort.

Transferosomes of famciclovir were prepared using tween 80, phospholipid, and cholesterol. To optimize drug entrapment and the vesicular size of the transferosomes, a central composite design was employed. The optimized formulation was evaluated for physicochemical characteristics, surface morphology, and degree of deformability. The optimized product was included in the Carbopol 940 gelling system. The gel was evaluated for ex vivo permeation, skin irritation, drug deposition at various skin layers, and histopathological analysis.

The design optimization yielded an optimized product (FAMOPT) of nanosized (339 nm) stable vesicles of the transferosome of famciclovir. The surface morphology analysis revealed the formation of nanovesicles without aggregation. Compatibility between the drug and excipients was established. The elasticity of the vesicles demonstrated resistance to leakage. The permeation of the drug was enhanced by 2.8 times. The gel was found to be non-irritating and non-sensitizing to the animal skin. The drug deposition at various skin layers was remarkably improved, indicating effective drug penetration. The histopathological examination further demonstrated the penetration of nano-vesiculate drugs through deeper layers of the skin.

Hence, nano-vesicular famciclovir delivery is a promising alternative to conventional famciclovir delivery with enhanced local and systemic action for herpes treatment.