Ternary Solid Dispersions of Celecoxib: from Physical Characterization to Dissolution Enhancement

Abstract

The poor solubility and wettability of a non steroidal anti inflammatory drug, celecoxib leads to poor dissolution and hence, low bioavailability after oral administration. The objective of the present study was to formulate solid dispersions of celecoxib, with water soluble polymers poly vinyl pyrrolidine (PVP K30), poly ethylene glycol (PEG 6000), hydroxypropyl methylcellulose 5cps (HPMC) and a super disintegrant namely pregelatinised starch (PGS) by common solvent and solvent evaporation methods. Solid Dispersions prepared were evaluated for dissolution rate and dissolution efficiency in comparison to the corresponding pure drug. Solid dispersions of celecoxib showed a marked enhancement in dissolution rate and dissolution efficiency. The increasing order of dissolution rate of solid dispersions of celecoxib with various polymers was HPMC > PVP > PEG. Solid dispersions at 2:2:6 ratio of C: HPMC: PGS, a 53.57 fold increase in the dissolution rate of celecoxib was observed. Solid dispersions were characterized by infrared spectroscopy (IR), differential scanning calorimetry (DSC) and X-ray diffractogram (XRD). Solid dispersions in combined carriers gave much higher rates of dissolution than super disintegrant PGS alone. Super disintegrant PGS alone or in combination with hydrophilic polymers could be used to enhance the dissolution rate of poorly soluble drug celecoxib. Finally, in-vitro dissolution studies showed that celecoxib release was greatly improved by formation of solid dispersion.