الفهرس | Only 14 pages are availabe for public view |
Abstract The objective of the present work is applying emulsion solvent evaporation technique for controlling the release of Ranitidine hydrochloride (RH) using two polymers, ethyl cellulose (EC) , Eudragit E100 (E E-100) and mixture of EC/E -E100. These investigations together with the obtained results and the attained conclusions can be summarized as follows: 1-The maximum wavelength of absorbance of RH was 312.6 nm in 0.1 N HCl and 224.6 in rabbit blood plasma. 2-The calibration curves of RH in 0.1 N HCl and in rabbit blood plasma obey Beer’s Lambert law in the concentration range used. 3-The formulae RH-E E100 (1:2.5) 400 rpm had the best value for the production yield (98.68%) while formula RH-EC (1:4) 400 rpm had the best value for Entrapment efficiency (79.3%) and formulae RH-E E100 (1:1) 400 rpm was the best one for in vitro buoyancy test (92%).Particle size of RH microspheres ranged from 66.77 to 10.41 μm. Optical microscope confirmed their spherical structure. 4-The micromeritic properties of the prepared RH microspheres indicated that emulsion solvent evaporation technique produces spherical microspheres with good flowability. 5-The amount of drug released decreased as the coat to core ratio increased. 6-The in-vitro release of RH from the RH/EC formulae followed Higuchi’s diffusion model While, RH-E E100 formulae followed First order models and RH-EC/E E100 formulae followed Zero o order kinetics. 7- Assessment of the AUC showed that the bioavailability is lesser for the pure drug (normal oral bioavailabili ty being only 50%) and increased to nearly 2.4-times with formulation. The elimination was less rapid with the microparticulate formulation when compared to the free drug and marketed product. 8-Both IR and DSC showed that there was no chemical interaction between the drug (RH) and the polymers (EC, E E100and EC/E E100). 9-The best formula in this study was RH-E E100 (1:2.5) 300 rpm which showed the best micromeritic properties, in vitro buoyancy and in-vitro release. |