Gande Suresh

The present study was aimed to develop and optimize extended release (ER) matrix tablets of Lamivudine trilayer tablets to achieve zero-order drug release for prolonged period of time. Lamivudine tablets were prepared by direct compression and consist of middle active layer with different grades of HPMC, MCC and PVP K30, upper and lower layers were prepared with Carnauba wax, Xanthan gum, EC and MCC. The tablets were also evaluated for physicochemical characteristics and release kinetics. The physicochemical characteristics of the prepared tablets were satisfactory. The developed drug delivery systems showed prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (HF23) was described by the Zero-order and Higuchi model. The results indicate that the approach used could lead to a successful development of extended release formulation of short biological half-life drug. These results also demonstrated the suitability of three-layered tablet formulation of Lamivudine to provide controlled release for prolonged period of time and improved linearity for Lamivudine in comparison to marketed product in the effective management of AIDS with patient compliance.

The present study was to formulate and characterize oral floating microspheres of Pramipexole to sustain the gastric residence time and to target gastritis. The floating microspheres were prepared by ionotropic gelation technique. Sodium alginate was used as polymer, sodium bicarbonate as gas generating agent, calcium chloride as cross-linking agent, HPMC K4, as rate retarding agent. Microspheres were characterized for the Micromeretic properties, incorporation efficiency, buoyancy test, SEM analysis, FTIR, and in vitro diffusion studies. The diffusion studies were carried out in 0.1N HCl and the results were applied to various kinetic models.  Among the total 14 formulations F12 was found to be optimized on the basis of different evaluation parameters. The % yield of F12 formulation was found to be 98.58%. On the basis of optical microscopy, the particle size was 65.12±0.04µm. The % buoyancy, % entrapment efficiency and swelling index of F12 formulation was 98.12%, 96.56% and 97.10, respectively. The Cumulative % drug release of F12 formulation was 98.3±5.10% in 12h.  SEM studies showed the particles were in spherical shape. On the basis of obtained results, Floating microspheres were of good candidate for targeting to GIT.

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.