Preparation and evaluation in vitro and in vivo of captopril elementary osmotic pump tablets
Lu Xu1, Sanming Li1, Hisakazu Sunada2*
1Department of Pharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, China2Faculty of Pharmacy, Meijo University, 150 Yagatoyama, Tempaku-ku, Nagoya 468-8503, Japan
Abstract Purpose: This study evaluated the release in vitro and the absorption in vivo for elementary osmotic pump tablet (EOPT) of Captopril (Cap). Methods: In the drug release study in vitro, the influences of the tablet formulation variables, the amount of NaCl, hydroxypropyl methylcellulose K15 (HPMCK15), microcrystalline cellulose (MCC) in the core, the concentration of cellulose acetate (CA), dibutylphthalate (DBP), and polyethylene glycol 400 (PEG-400) in the coating solution have been investigated. The optimal tablet formulation has been proposed. With immediate release tablets currently on the market as the reference, the relative bioavailability and pharmacokinetics in dogs were studied in vivo. Results: It was found that the drug release was mostly affected by the amount of NaCl, HPMCK15, and MCC in the core, and the amount of PEG-400 in the coating solution. To a certain extent, drug release was less affected by the orifice size, concentration of coating solution, and the coating weight. It was also independent of the pH of the dissolution medium and orifice quantum. The drug release mechanism has been shown to involve release kinetic derived from differences in the osmotic pressure across the membrane. The relative bioavailability of EOPT was 119.9%. EOPT showed a good correlation between absorption in vivo and drug release in vitro. Conclusion: Cap EOPT is a safe and effective controlled release preparation.
Lu Xu,
Sanming Li,
Hisakazu Sunada
.Preparation and evaluation in vitro and in vivo of captopril elementary osmotic pump tablets[J] AJPS, 2006,V1(3-4): 236-245
2006, Vol. 1 