Analytical method development and method validation for assay, related substances and degradants of acyclovir and valacyclovir as antiviral drug products

Abstract

From the Literature study it is unable to find the combined HPLC methods for Acyclovir and Valacyclovir using HPLC-UV detector. However, an analytical method for individual analysis for Acyclovir and Valacyclovir was published. So It is felt necessary that to develop HPLC method for quantitative determination of Acyclovir and Valacyclovir. It was also found that there are some analytical methods reported for the Acyclovir and valacyclovir separately and most of the works reported were done on the biological fluids. Based upon the data of previous literature review and results of published methods, the trials of method development taken and finalized the method for validation of assay and related substances with degradants study. The finalized method is achieved on HPLC column Inertsil cyno column, (250and#61620;4.6mm dimensions) having particle size 5and#61549;m, with flow rate as 0.8 ml/ min and column oven temperature as 50o C. The buffer was prepared by dissolving 1.00 g of Ammonium acetate in 1000 ml water, filtered through 0.45µm membrane filter and degassed in ultrasonic bath prior to use as mobile phase A . Acetonitrile is the organic solvent used as mobile phase B in isocratic mode. The injection volume amounted to 5and#61549;l. The analysis was carried out under isocratic condition as mobile phase A: Mobile phase B is (95:5). Detection was monitored at the wavelength of 254 nm. Diluent used was a mixture of acetonitrile and water in the ratio of (50:50) in the preparation of analytical solutions. According to the International Conference on Harmonization (ICH) guidelines taking into consideration the specified limits for Acyclovir and Valacyclovir Tablets and based upon the results obtained from the method validation are summarized below,