Evaluation and comparison of five matrix excipients for the controlled release of acrivastine and pseudoephedrine

For treatment of allergic rhinitis, acrivastine with pseudoephedrine in Semprex(R)-D conventional capsules requires dosing every 6-8 hours. This study was designed to develop a controlled release matrix tablet of acrivastine and pseudoephedrine and evaluate 5 different matrix excipients for their in vitro controlled-release profiles. Compritol(R) 888ATO, Eudragito(R) RS, Methocel(R) K100M, Polyox(R) WSR301 and Precirol(R) ATO5 were used alone or in varying combinations for the formulation of controlled release matrix tablets. In vitro drug dissolution and mathematical modeling were used to characterize drug release rate and extent. All tablet formulations yielded quality matrix preparations with satisfactory tableting properties. Due to the aqueous solubility of pseudoephedrine and the size of the dose, none of the matrix excipients used alone prolonged drug release significantly to meet the desired twice-daily administration frequency. The use of two excipients in combination, however, significantly decreased the dissolution rate of both active ingredients. A combined lipid-based Compritol(R) and hydrophilic Methocel(R) produced optimal controlled drug release for longer than 8 hours for both acrivastine and pseudoephedrine.