Influence of drug:hydroxypropylmethylcellulose ratio, drug and polymer particle size and compression force on the release of diclofenac sodium from HPMC tablets

This study evaluates the relationship and influence of formulation and technological factors such as drug:hydroxypropylmethylcellulose (HPMC) ratio, particle size of the drug, particle size of HPMC and compression force, on drug release from matrices containing HPMC and diclofenac sodium as a model drug. The influence of these variables was assessed by multi-way analysis of variance. The results of the present study point out that the rate and mechanism of diclofenac sodium release from HPMC K15M matrices are mainly controlled by the drug:HPMC ratio. The drug and HPMC particle size also influence the drug release parameters, although to a lesser extent. Finally, the independence of the drug release from matrix tablets with respect to the compression force is reported. (C) 1999 Elsevier Science B.V. All rights reserved.