STUDY OF DIABIETIC ACID AS MATRIX FORMING MATERIAL

Abietic acid was extracted from rosin N grade and further standardized . Diabietic acid, a derivative of abietic acid was prepared by dimeriz ation with sulfuric acid and evaluated for different physicochemical p roperties. A yellowish brown colour product with an acid value of 98 m g KOH, a softening point of 142-145 degrees C and an acid/alkali resis tant property was obtained. Moisture absorption study indicated its hy drophobic nature. Water vapour transmission and scanning electron micr ography showed that the free films of diabietic acid are smooth, flexi ble, nonporous with 0.024 g h(-1) mmHg of water vapour transmission ra te at 82.5% relative humidity (RH). Matrix tablets of Diclofenac sodiu m were formulated using diabietic acid as a matrix-forming material an d evaluated for hardness, friability, release characteristics and mate rial balance study. The results showed that diabietic acid having good film forming, acid/alkali resistant properties could be successfully used to prolong release of water-soluble drug for up to 24 h.