Formulation and Evaluation of Sustained Release Matrix Tablet of Zidovudine Using Different Polymers

In the present investigation, an attempt was made to formulate the oral sustained release matrix tablets of zidovudine in order to improve efficacy, reduce the frequency of administration, and better patient compliance. Differential scanning calorimetric analysis confirmed the absence of drug polymer interaction. The sustained release tablets were prepared by wet granulation method using different polymers viz, hydroxypropyl methylcellulose, xanthan gum, and ethyl cellulose as release retardant polymers, alcoholic solution of polyvinylpyrrolidone were used as granulating agent. In- vitro release studies were carried out at pH1.2 for first 2 hrs followed by phosphate buffer at pH7.4 over a period of 8hrs using USP dissolution apparatus. The formulated granules showed satisfactory flow properties. All the tablets formulation showed acceptable pharmaco technical properties and complied with pharmacopoeial standards. The in-vitro release profiles from tablets of drug and different polymer ratio were applied on various kinetic models. Based on t90% values the formulation F9 was found to show good initial release (12% in 2 hrs) and may extend the release (90% in 10 hrs) and can overcome the disadvantages of conventional tablets of Zidovudine. The n value obtained from korsmeyer – peppas model confirmed that the drug release was non- fickian diffusion mechanism.