INFLUENCE OF PHYSICOCHEMICAL PROPERTIES OF HYDROXYPROPYL METHYLCELLULOSE ON NAPROXEN RELEASE FROM SUSTAINED-RELEASE MATRIX TABLETS

Hydroxypropyl methylcellulose 2208 (HPMC 2208) was used as the rate-controlling polymer in a naproxen controlled release tablet formulation. A study was undertaken to correlate the physicochemical properties (e.g., molecular weight, particle size, hydroxypropyl and methoxy content, etc.) of different lots of HPMC 2208 from two suppliers with in vitro drug release. All lots had varying chemical compositions but identical particle size sieve fractions. The dissolution of tablets manufactured with seven lots of HPMC 2208 were evaluated. The results indicated that the hydroxypropyl content of HPMC 2208 is the major factor that controls drug release. Irrespective of the supplier, drug release was directly proportional to the hydroxypropyl content. Since the dissolution performance of this product was dependent on the chemical composition of the HPMC 2208, which has wide compendial specifications, the results indicate that pharmaceutical manufacturers must be aware of the potential consequences of either lot to lot variability or changing suppliers of HPMC 2208 without proper characterization. Furthermore, this work demonstrated that compendial specifications for this excipient may be too broad for certain types of dosage forms. © 1990.