Discriminatory Dissolution Method Development and Validation for Cephalexin Od Tablets

In this study, a discriminative dissolution method was developed for Cephalexin OD (orally disintegrating) tablets 750mg. The solubility and stability of the cephalexin API was determined in ten different solutions. In that 0.01N HCl, glycine buffer pH 3-0, acetate buffer pH 4.5 and water gave good stability and the solubility. Dissolution profiling of cephalexin OD tablets 750mg of single batch was done with the selected media containing varying concentration of surfactants (tween 80 and Sodium lauryl sulphateSLS). The release profile is compared with that of the control media. The media that gave discriminately faster release than that of the control were found to be 0.01N HCl with 0.75% of tween 80, 0.01N HCl with 0.5% of SLS, acetate buffer with 1% of tween 80 and water with 0.5% of SLS. With the selected media, dissolution profile was done on the three different batches of cephalexin OD tablets one with lesser polymer ratio and other with higher polymer ratio that that of the test batch. Only 0.01N HCl with 0.75% of tween 80 as dissolution medium was found to show good discrimination in the release profile with change in the formulation conditions. The discriminative dissolution method developed was validated for its specificity, accuracy, stability, linearity and precision and it passes all the parameters. INTRODUCTION: Dissolution 1 is defined as the process by which a solid substance enters in the solvent to yield a solution. Pharmaceutical solid dosage forms and solid liquid dispersed forms on administration undergo dissolution in biological media followed by adsorption of drug entity in to systemic circulation. In determining the dissolution rate of drug from solid dosage forms under standardised condition one has to consider several physic chemical processes in addition to the process involved in the dissolution of pure chemical substances. The physical characteristics of dosage form the wettability of the dosage unit the penetration ability of the dissolution medium , the swelling process, the disintegration and de aggregation of the dosage form are a few of the factors that influence the dissolution characteristic of the drug. Discriminative dissolution is a method which is sensitive to change in formulation, raw materials characteristic and critical manufacturing variables is said to be discriminative. Dissolution is the important parameter to forecast the bioavailability. Dissolution method should be developed which can differentiate the formulation manufactured by the same process. In official or QC release method, the two products may show same dissolution profile but when discriminative