BIOAVAILABILITY OF IBUPROFEN FROM HARD GELATIN CAPSULES CONTAINING DIFFERENT VISCOSITY GRADES OF HYDROXYPROPYLMETHYLCELLULOSE AND SODIUM CARBOXYMETHYLCELLULOSE

The effect of viscosity grade (molecular weight group) of the polymer diluent on the bioavailability of ibuprofen from hard gelatin capsules was evaluated in two single-dose (400 mg) cross-over studies in healthy volunteers following an overnight fast. The polymers studied were nonionic hydroxypropylmethylcellulose (HPMC) K100 and K15M, and anionic sodium carboxymethylcellulose (NaCMC) LV, MV and HV. Plain ibuprofen capsules were used for reference. Use of HPMC K15M led to markedly sustained drug absorption from the capsules. The t(max) and C(max) values differed significantly (P < 0.001) from the reference values. The sustaining effect of the lower viscosity grade, K100, was less pronounced. NaCMC-based capsules exhibited sustained-release properties similar to those of the HPMC K100 capsules. In the case of NaCMC, the molecular weight of the polymer had no significant effect on drug absorption. No differences in the extent of bioavailability of ibuprofen between the formulations studied were evident.