Evaluation of release-retarding potential of co-processed excipients on Quetiapine fumarate sustained release tablets.

Despite enormous advancements in drug delivery systems, tablets remain the most frequently used dosage forms. The tablet formulation involves a variety of excipients to convert a drug into a compressible mass since a single excipient is not always able to provide the essential characteristics that allow an active pharmaceutical ingredient to be formulated into tablets. Formulation scientists in recent years have been trying to reduce the number of excipients to minimize the cost and improve the overall manufacturing procedure. An alternative approach involving new combinations of existing excipients (co-processed excipients) seems to be an interesting option. The co-processed excipients comprise a mixture of two or more excipients that interact at the sub-particle level giving rise to an excipient with improved functionality. The present study investigates the drug release-retarding potential of co-processed excipients on Quetiapine fumarate tablets. The whole study comprises pre-formulation studies, optimization of formulation using factorial design, and post-formulation evaluations. Co-processed excipients were prepared by a solvent evaporation method using a rotary evaporator. For the preparation of Quetiapine fumarate sustained release tablets, 32 factorial design was employed keeping the dose of the drug constant. The prepared powder blend resulted in acceptable free-flowing characteristics. Physical evaluation of sustained release tablets showed uniform weight and content uniformity within the acceptable variation. All formulations showed acceptable mechanical properties with good hardness and acceptable friability. The drug release profile of the formulation was observed to be comparative with marketed the formulation. Hence, it can be concluded that the co-processed excipients were able to sustain the drug release for up to 24 hrs. [ABSTRACT FROM AUTHOR]