Development of a floating multiple unit controlled-release beads of zidovudine for the treatment of AIDS

Zidovudine is the first approved compound for the treatment of AIDS, and having short biological half-life and poor bioavailability. The present research work an attempt has been made to design the zidovudine gas powered multiple unit drug delivery system for controlled release. Floating beads are often used for controlled drug release as they have a gastroretentive property without affecting the gastric emptying rate. In the present study zidovudine-controlled release beads were prepared with the help of the ionotropic gelation method, using sodium alginate containing KHCO3 as the gas-forming agent. The beads were subjected to in-vitro drug release, kinetic studies and stability studies. FTIR and DSC studies shown there was no interaction between drug and polymers. The percentage of zidovudine content from the beads was determined by UV-spectroscopy and ranged from 93.76 ± 0.44 to 98.14 ± 1.10. The in-vitro percentage release of zidovudine from the beads at the end of 12 h ranged from 86.10424 to 96.83746. The kinetic studies revealed that the drug was released by zero-order kinetics. The optimized formulations were subjected to stability studies and shown there were no significant changes in drug content, physicochemical parameters and release pattern. The floating beads designed for the gastroretentive dosage form could be suitable for controlled drug delivery.