Formulation and Evaluation of Extended Release tablets of Valacyclovir by DoE Implementation

B. Ranganayakulu*, S. Bindu Bhargavi¹, S. Mohammed Yusuf²
*^,2Associate Professor, Srinivasa Institute of Pharmaceutical Sciences, Proddatur, A.P., India
¹Srinivasa Institute of Pharmaceutical Sciences, Proddatur, A.P., India

A B S T R A C T
Recent scientific and patent literature shows increased interest in academics & industrial research groups regarding novel dosage forms that can be retained in the stomach for prolonged & predictable period of time and the most feasible approach for this is to control the gastric residence time using gastro-retentive dosage forms which will provide new & important therapeutic option but the problem can arise if there is a narrow window for drug absorption in the GIT or drug is unstable in the intestinal fluid. So the development of oral controlled dosage form is not just to prolong the drug release but also to ensure the presence of dosage form in the stomach or upper GIT so that drug is released and absorbed for the desired period of time. Valacyclovir was used with various ingredients like HPMC K15, HPMC K4M, Eudragit, MCC 102 and Aerosil. The tablets were prepared by wet granulation method. Fourier-transform infrared (FTIR) studies of the prepared tablets and the drug and the excipients showed compatibility. Observations of all formulations for physical characterization had shown that, all of them comply with the specifications of official pharmacopoeias and/or standard references. Results of in-vitro release profile indicated that formulation (F7) was the most promising formulation as the extent of drug release from this formulation was high as compared to other formulations. DoE is implemented by applying 2 level 3 factor full factorial design by using Design Expert software version 7.  From DoE studies it were showed that as increase in concentration of Eudragit, MCC 102 and HPMC the drug release also increased and by maintaining the concentrations in required range the extended release is shown.
Keywords: Valacyclovir, Extended Release tablets, Evaluation, DoE implementation