Journal of Pharmaceutical Research

Abstract

Objective: Synthetic nucleoside analogue drugs are effective antiviral agents that inhibit polymerase. However, long-term storage without freezing remains a challenge. In this study, we aimed to develop an intravenous injection of acyclovir sodium, a compound known for its instability in aqueous solutions, by using lyophilisation technology to extend its shelf life and improve its stability. Methods: Lyophilization was performed on multiple batches with variations in total cycle time, freezing and holding time, and primary and secondary drying times, while keeping the quantities of active pharmaceutical ingredients constant. The process was optimised to achieve a total lyophilisation cycle of 51.75 hours. The resulting lyophilised product was evaluated for several in vitro parameters including cake appearance, reconstitution time, pH, assay, related substances, particulate matter, water content, colour value, percentage light transmittance, and Differential Scanning Calorimetry (DSC). Findings: Batch-V was identified as the optimised formulation based on its compliance with all the USP specifications and evaluation parameters. Accelerated stability studies confirmed that this formulation remained stable under the tested conditions, demonstrating the effective preservation of product quality over time. This study presents a significant improvement in stabilising acyclovir sodium at a concentration of 1 gram per vial, demonstrating the efficacy of lyophilisation in maintaining drug stability. Novelty: This study demonstrates that lyophilisation enhances the stability of acyclovir sodium injections, extending their shelf life beyond aqueous solutions, offering a potential solution to overcome the long-term storage limitations of nucleoside analogues.

Keywords: Acyclovir sodium, lyophilization, Differential Scanning Calorimetry