K.M. Manjanna^1,, K. S. Rajesh², B. Shivakumar³

The objective of this study was to prepare and evaluate calcium alginate (CA) microbeads with calcium chloride as cross-linking agent for aceclofenac sodium by ionotropic external gelation method. Calcium alginate microbeads represent a useful tool for oral sustained/ controlled drug delivery but show several problems, mainly related to the stability, and rapid drug release at higher pH that, in most cases, is too fast due to increase porosity. To overcome such inconveniences, which was to develop CA microbeads coated with Guar gum (GG) and Locust bean gum (LBG) as drug release modifiers to improve stability and prolong the drug release. While increasing in the concentration of sodium alginate and other polymer dispersion increased size distribution, flow properties, mean particle size, swelling ratio and drug entrapment efficiency. The mean particle sizes of drug-loaded microbeads were found to be in the range 596.45±1.04 to 880.10±0.13. The drug entrapment efficiency was obtained in the range of 63.24±0.66 to 99.75±0.87. The shape and surface characteristics were determined by scanning electron microscopy (SEM). No significant drug-polymer interactions, physical changes and crystallinity of the drug in the formulations were determined by FT-IR spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction [XRD]. In-vitro drug release profiles of microbeads were pH dependent and were analyzed by different kinetic models. The mechanism of drug release from microbeads depends on swelling and erosion process resulting CA microbeads was diffusion controlled followed by First order kinetics and whereas CA microbeads coated with GG and LBG approaching to near Zero- order kinetics.

Sodium alginate, aceclofenac sodium, Natural polysaccharides, Oral controlled drug delivery, Zero-order kinetics