CADMIUM CHLORIDE INDUCED CHANGES IN PROTEIN MOLECULES OF THE FRESHWATER FISH CIRRHINUS MRIGALA (HAMILTON)

Abstract                       The fresh water fish Cirrhinus mrigala (Hamilton) was exposed to the heavy metal Cadmium chloride for 24, 48, 72, and 96 h, and the consequential LC50 values were calculated using Finney's probit analysis. The LC50 values obtained for 24, 48, 72, and 96 h were 317.5, 316.5, 316.0 and 315.5 respectively. Later the fish were exposed to 96 h acute lethal and sub-lethal concentrations and the changes in protein subunits were analyzed in the tissue of the vital organs such as brain, liver, muscle, gill and kidney using SDS-PAGE electrophoresis. The results revealed that among the protein molecules some became faded when compared to control fish protein molecules, whereas some protein bands disappeared. The analysis was made with the help of standard protein marker. The changes are more pronounced in the tissue of liver and muscle, which may be due to the involvement of liver in the detoxification mechanism. Whereas in case of muscle the changes in the protein banding pattern may be due to the consumption of energy through erratic movement caused due to the toxicant stress. It was also observed that the changes in kidney protein molecules is also more and this may be  due to the accumulation of cadmium chloride in kidney tissue. The results obtained were discussed at length with the available literature. Key words: Cadmium chloride, Cirrhinus mrigala, Protein molecules, Liver, LC50 and        SDS-PAGE

Floating Drug Delivery of Nevirapine as a Gastroretentive System

A multiple-unit floating drug delivery system based on gas formation technique was developed, in order to prolong the gastric residence time and to increase the overall bioavailability of the dosage form. The floating bead formulations were prepared by dispersing nevirapine together with calcium carbonate in a mixture of sodium alginate and hydroxypropyl methylcellulose solution and then dripping the dispersion into an acidified solution of calcium chloride. Calcium alginate beads were formed, as the alginate underwent ionotropic gelation by calcium ions, and carbon dioxide developed from the reaction of carbonate salts with acid. The obtained beads were able to float due to CO2-gas formation and the gas entrapment by the polymeric membrane. The prepared beads were evaluated for percent drug loading, drug entrapment efficiency, morphology, surface topography, buoyancy, in-vitro release, and release kinetics. The formulations were optimized for different weight ratios of the gas-forming agent and sodium alginate. The beads containing higher amounts of calcium carbonate demonstrated an instantaneous, complete, and excellent floating ability over a period of 24 hours. The increased amount of the gas forming agent did not affect the time to float, but increased the drug release from the floating beads, while increasing the coating level of the gas-entrapped membrane, increased the time to float, and slightly retarded the drug release. Good floating properties and sustained drug release were achieved. Finally, these floating beads seemed to be a promising gastroretentive drug delivery system