ENHANCEMENT OF DISSOLUTION RATE OF CARBAMAZEPINE: I- IN VITRO STUDIES

Document Type : Original Article

Author

Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

Carbamazepine (CBZ) is an antiepileptic drug which shows variable absorption and variable bioavailability due to poor solubility. Three approaches were utilized to enhance the dissolution rate namely, solvent deposition onto porous silica, co-grinding with porous silica, egg albumin or polyvinylpyrrolidone and surface hydrophilization with non-ionic surfactant or propylene glycol. The molecular behavior of CBZ in the investigated systems were studied using X-ray diffraction analysis and differential scanning calorimetry. The dissolution rate of the drug was also investigated. The obtained results indicated that CBZ was transformed to the amorphous state in both the ground and loaded mixtures with porous silica. This transformation resulted in significant enhancement of the dissolution rates of the drug. Surface hydrophilized rug using 1% w/w polyoxyethylene sorbitan monolaurate (polysorbate 20) showed higher dissolution rate and good compliance with respect to tablet characteristics according to BP 1993 limits.