Development of Liposomal Formulation for Controlled Delivery of Valacyclovir: an In Vitro Study

Purpose Herpes, a highly contagious viral infection caused by the herpes simplex virus, infects the face to any other body part of the skin, even the genital areas. Among the anti-herpes drugs, valacyclovir (VCV) possesses 55-70% oral bioavailability and more improved performance than acyclovir (15-20% oral bioavailability). However, a high daily intake of around 1 g is required. This work aimed to prepare a suitable carrier system to enhance bioavailability of VCV with reduced dose and dose-related side effects.Methods The processes of thin film hydration and reverse-phase evaporation were employed to synthesize liposomes encapsulating VCV, which were then subjected to basic characterizations such particle size and zeta potential. Moreover, FESEM and cryo-EM studies of the optimized formulation were also performed. FTIR spectroscopy was performed to detect incompatibility present if any between drug and excipients. The percentage drug loading and in vitro drug release were studied by UV-Visible spectrophotometer.Results The results showed that the liposome vesicles were in nanosize range (140 & PLUSMN; 4.1 nm) with good colloidal stability (-62.75 & PLUSMN; 3.18 mV; the zeta potential) with appreciable drug loading capability. In vitro drug release studies revealed a biphasic release pattern, with initial burst release lasting up to 2 h and then continuous drug release. About 73% drug was released after 48 h.Conclusion Based on the findings, it was determined that VCV, a widely used drug for the treatment and prevention of viral infections in humans, may be formulated as a liposome for the successful treatment of herpes with a lower dose and improved bioavailability.

Automated summary

The purpose of this study was to prepare a suitable carrier system to enhance the bioavailability of valacyclovir (VCV) and reduce dose-related side effects for the treatment of herpes. Liposomes encapsulating VCV were synthesized using thin film hydration and reverse-phase evaporation methods. The liposomes showed nanosize range, good colloidal stability, and appreciable drug loading capability. In vitro release studies revealed a biphasic release pattern with initial burst release followed by continuous drug release. The findings suggest that VCV formulated as a liposome can effectively treat herpes with a lower dose and improved bioavailability.