Floating microspheres

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.  

The aim of the current study was to formulate and characterize oral floating alginate microspheres of Rebamipide to sustain the gastric residence time and to target gastritis. The floating alginate 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, HPMC K15 as rate retarding agent. Microspheres were characterized for the Micromeretic properties, entrapment efficiency, buoyancy test, SEM analysis, FTIR, and in vitro release studies. The release studies were carried out in 0.1N HCl and the results were applied to various kinetic models.  Among the total 14 formulations F12 was optimized. The % yield of F12 formulation was found to be 93.73%. On the basis of optical microscopy, the particle size was 79.45±0.09µm. The % buoyancy, % entrapment efficiency and swelling index of F12 formulation was 94.2%, 95.5% and 96.16, respectively. The Cumulative % drug release of F12 formulation was 96.12±0.22% in 12h when compared with marketed product 95.15±0.23 in 1h.  SEM studies showed the particles were in spherical shape. Based on obtained results, floating alginate microspheres were of good candidate for targeting to GIT in the efficient management of gastritis.

The present work reports on the preparation of ethyl cellulose (EC)-pluronic F127 (PF127)-based tableted floating microspheres by the oil-in-water emulsion solvent evaporation method for the controlled release of acyclovir (ACV). Microspheres of this study were characterized by Fourier transform infrared (FTIR) spectroscopy to investigate the chemical interactions of ACV with the polymer, floating behavior, scanning electron microscopy (SEM) for morphology of the microspheres, differential scanning calorimetry (DSC) for investigating their thermal properties  and X-ray diffraction (XRD) as well as. In vitro release experiments of microspheres were performed in acidic pH 1.2 media to understand the release profiles of ACV. The selected sets of microspheres were compressed into tablets using the compressible excipients and their in vitro release performances were evaluated in pH 1.2 media.

Most demanding route of administration is oral. Several times dosing of conventional drug delivery system to achieve effective therapeutic range is always abhorred by the patient. Demanding new approach to reduce the number of intake; leading to introduction of gastric retention concept. As most of drugs are absorbed in upper intestinal tract GI retention was base to it. The floating drug delivery system is an admirable approach to gastric retention. Aim of delineating this review on Floating Drug Delivery System was to stash up the recent literature with special cogitation toward principal mechanism to attain gastric retention, also including details of Floating Drug Delivery System such as Classification, Mechanism of work, Method of preparation, Aspect of characterisation, Different factors to be taken care during process of formulation. This review is loaded with data of previous work performed on Floating Drug Delivery System, which includes desirable point to solve, the queries regarding FDDS.