α-(1→4)-linked D-galacturonic Acid Based Linear Homopolymer as Drug Release Modulator in HPMC Based Hydrodynamically Balanced System

Objectives: Natural polysaccharides are increasingly being used for diverse applications in drug delivery such as controlled release of drugs owing to their wide availability, renewability, biodegradability and biosafety. Furthermore, polysaccharides from plants utilized as food may possibly mitigate regulatory requirement for approval as well. Mung bean (Vigna radiata L. seeds) is a key cereal in India composed of several non-starch polysaccharides. In the present work we have attempted to isolate, characterize and pharmaceutically evaluate the polysaccharide derived from dehusked Mung beans using water-acetone precipitation method. Methods: The obtained polysaccharide was characterized using Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, Powder X-ray diffraction and 13C Nuclear Magnetic Resonance spectroscopy. Further, the polysaccharide derived from Mung beans was carboxymethylated using Williamson Ether Synthesis. The degree of substitution of carboxymethylated Mung bean polysaccharide was determined to be 0.76. The carboxymethylated polysaccharide was then used in combination with hydroxypropyl methylcellulose K4M to fabricate hydrodynamically balanced sustained release capsule dosage form taking moxifloxacin HCl as model drug. Results: The system emerged as a hydrodynamically balanced system that remains floated for 12 hr. The drug release mechanisms involved swelling, dissolution and erosion of polymer matrices. The erosion operated at later times and was sensitive to the osmotic stress exerted by ionic polymer and the drug present in the matrix. Conclusion: The findings of the study suggest that polymer matrices composed of chemically modified Mung bean polysaccharide and hydroxypropyl methylcellulose K4M may form a promising carrier for sustained stomach specific delivery of model drug moxifloxacin Hydrochloride.