APPLICATION OF QUALITY BY DESIGN (QBD) IN FORMULATION DEVELOPMENT OF IMMEDIATE AND EXTENDED RELEASE BILAYERED TABLETS OF DEXTROMETHORPHAN AS A MODEL DRUG

Quality by Design (QbD) is an approach in the design and development of the formulation by using different scientific strategies, tools and previous data available. QbD can assist the pharmaceutical industry and research scholars to satisfactorily move towards the more scientific, active, risk-based pharmaceutical development. Qbd, if applied, to the entire product cycle minimizes the end product testings and leaves one with safe, effective and quality product. In the present study, an attempt is made to apply the QbD to the Dextromethorphan, a highly potent opiod analgesic and antitussive drug which have relatively lesser addictive and narcotic properties. It is designed in immediate and extended release manner for better therapeutic efficacy. Due to the shorter half life of Dextromethorphan it needs to be taken four to five times a day. To reduce the frequency of dose it can be formulated in extended release form by wet granulation method. The tablets were prepared by direct compression of matrix-type immediate release layer and ethyl cellulose coated extended release layer in bilayered rotary press (Remik, Mini Press II DL). Physical mixture of drug and the excepients is found to be compatible when evaluated using FTIR and the tablets are evaluated for hardness, thickness, weight variation, friability, content uniformity, distintegration and dissolution profile. The effect of Binder, superdistintegrant and coating concentrations are also optimized by using the design space and other plots with the help of Minitabs Software version 17. The prepared formulation showed better dissolution profiles than the available products.