Sodium alginate.

The purpose of the study was to formulate floating alginate beads of Nevirapine (NVP), an Anti-HIV agent. Inspite of long half life (45 hrs) a Nevirapine controlled release once daily formulation could be used to maintain optimum peak plasma concentration for effective viral suppression. The floating bead formulations were prepared by dispersing Nevirapine together with Sodium bicarbonate in a mixture of sodium alginate and Hydroxypropyl methylcellulose solution and sunflower oil and then dripping the dispersion into an acidified solution of calcium chloride. Calcium alginate beads were formed, as the alginate underwent Emulsion 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 beads containing higher amounts of calcium carbonate demonstrated an instantaneous, complete, and excellent floating ability over a period of 24 hours. And this floating beads are compared and evaluated with Nevirapine floaing gel, Good floating properties and sustained drug release were achieved. Finally, these floating beads seemed to be a promising gastro retentive drug delivery system.

Ciprofloxacin hydrochloride is a fluoroquinolone antibiotic, widely effective in the treatment of ophthalmic disorders like, corneal ulcers and conjunctivitis. In the present study, an attempt has been made to formulate ciprofloxacin hydrochloride as sustained release in situ gel systems utilizing the concept of ion- activated gelation using Gelrite alone and with sodium alginate in combination with HPMC E50 LV. Prepared formulations were evaluated for several parameters like drug polymer compatibility, viscosity, gelling and gel retention time, clarity, pH, drug content, antimicrobial efficacy, sterility and in vitro drug release. Among all the formulations, batches G3 containing 0.6 %w/v of Gelrite, A6 and A7 containing 1% w/w of sodium alginate with 0.5 and 0.75 % w/v of HPMC E50LV respectively were selected based on their gelling properties. The drug release of A6 extended upto 7 h and that of G3 and A7 extended upto 8 h. The formulations showed pseudo plastic behaviour after gelling. G3 showed better stability and clarity than the alginate formulations and was taken for further evaluations. It showed better antimicrobial efficacy when compared with standard. The mechanism of drug release from the best formulation was further evaluated. Hence the developed in situ system may be an alternative to conventional eye drops.