Natural Gellan Gum (Phytagel®) Based Novel Hydrogel Beads of Rifampicin for Oral Delivery with Improved Functionality

Background: Despite exhaustive global efforts, tuberculosis (TB) continues to higher rates of infection and drug resistance rates are also raising to alarming levels. Sustained release dosage forms are gaining higher acceptance over conventional dosage forms in the treatment of several chronic conditions including TB. The aim of this study was to investigate whether the novel particulate system improved the drug release profile of rifampicin when formulated with natural polymer based hydrogel beads along with beta cyclodextrin as a solubility enhancer. Materials and Methods: Particulate hydrogel beads were prepared by ionotropic gelation method using divalent calcium cations. Prepared beads were coated with chitosan through polyelectrolyte complexation. Formulations were evaluated for drug content, particle size, swelling index and in-vitro dissolution, and further characterized by Scanning Electron Microscopy, Fourier Transfer Infrared Spectroscopy, Differential Scanning Calorimerty and X-Ray Diffractometry. Results: All the formulations showed sustained drug release but the formulation G2 exhibited highest amount of drug release among all. While considering the formulations with cyclodextrin the release rate is slightly increased at initial hours. The formulations with chitosan coating showed sustained release up to 24 h. Conclusion: Utilization of natural polymers was proved to be effective in formulating a novel particulate sustained release solid dosage form of rifampicin and presence of cyclodextrin proved to be useful in solubility enhancement which can achieve higher drug release.