Release order kinetics.

ABSTRACT: The aim of the present study is to design and evaluate the controlled release Glyburide trilayer matrix tablets, to achieve zero-order drug release for sustained plasma concentration. Matrix tablets were prepared by direct compression whereas three-layer tablets were prepared by compressing polymer barrier layers on both sides of the core containing the drug. Formulations were prepared by using different grades of hydroxy propyl methyl cellulose and Ethyl cellulose. Based on the evaluation parameters, drug dissolution profile and release drug kinetics HF16 was found to be optimized formulation. These results also demonstrated the suitability of three-layered tablet formulation of Glyburide to provide controlled release for prolonged period and improved linearity for Glyburide in comparison to marketed product in the management of Diabetes. Keywords: Glyburide, Type II Diabetes, HPMC Grades, EC, MCC, Release order kinetics.  

ABSTRACT: Floating microspheres of Tolcapone was prepared by ionotropic gelation method with an aim of increasing the gastric residence time and for controlled release using different polymers like HPMC K4M and HPMC K15M as rate retarding agent in concept to optimize the formulation. The FTIR studies indicated no significant interaction observed between drug and excipients. The F12 formulation showed the excellent flow properties. % yield, % entrapment efficiency and swelling index of optimized formulation was found to be 98.45%, 98.02% and 98.50%, respectively. The %buoyancy was excellent with approximately 98.42% of the microspheres floating upto 24h. The Cumulative % drug released from F12 microspheres was found to be 98.26±5.05% with in 12h and compared with the marketed product 91.25±5.00%. The optimized formulation F12 best fitted into zero order and Higuchi kinetics indicating diffusion controlled drug release pattern. SEM studies showed spherical shape and revealed the presence of pores on the floating microspheres surface which was responsible for floating ability. From stability studies optimized microspheres were stable at for 6 months. The F12 formulation showed the better results with HPMC K15M compared with HPMC K4M as rate retarding polymer. These results indicated that the Tolcapone loaded microspheres could potentially be exploited as a delivery system with controlled drug release in the effective management of Parkinson’s disease. Keywords: Floating microspheres, Tolcapone, HPMC, %buoyancy, Release order kinetics.