Flowability Optimization of Sodium Divalproex Powder Using Central composite Design

Effective formulation of a stable solid dosage form depends on the proper selection of its excipients.The aim of this project is to optimize the flowability of Divalproex sodium powder (which has a waxy nature and poor flowability) using the central composite design. To this end, different excipients were used to improve the flowability of the powder.

The formulation design was carried out using central composite design with different excipient- drug ratios. The flow rate of the formlations were determined by flow meter machine and analyzed using Minitab software and then used for evaluation of the model. The suitable formulations were selected by this software in the aspect of flowability.

The results indicates that different amounts of excipients can cause different powder flowability characteristics. Adsorption of aerosil to powder surface as a glident,up to 2.75 gram improves its flowability, however in higher concentrations the reverse effect in powder flow is observed.Moreover lactose and Avicel in amounts of 2.5 and 7.5 g in Divalproex sodium tablet formulation respectively result in an accepted flowability.

It can be concluded that using central composite design is a shortcut method to design suitable formulations of divalproex sodium with appropriate flowability.