Formulation and evaluation of sustained release saxagliptin microspheres by ionotropic gelation method

The objective of the current investigation is to reduce dosing frequency and improve patient compliance by designing and systematically evaluating sustained release microspheres of an antidiabetic agent, saxagliptin. Saxagliptin microspheres were formulated using sodium alginate as the controlled release polymer by ionotropic gelation technique. The polymer sodium alginate alone and along with different coating polymers like pectin, ethyl cellulose was used in different ratios (1:1,1:1.5, 1:2) to formulate batches F1 to F9. The resulting microspheres were evaluated for particle size, densities, flow properties, morphology, recovery yield, drug content, drug entrapment efficiency and  in vitro  drug release behavior. The formulated microspheres were discrete, spherical with relatively smooth surface, and with good flow properties. The drug entrapment efficiency obtained in the range 70.4% to 95.2%. Among different formulations, the fabricated microspheres of batch F3 had shown the optimum percent drug encapsulation of microspheres and the sustained release of the saxagliptin for about 9 h.  In vitro  study showed that drug release slowly increases as the pH of the medium is increased. Release pattern of saxagliptin from microspheres of batch F3 followed Higuchi model and zero-order release kinetic model. The value of ‘n’ was found to be 0.867. The data obtained thus suggest that a microparticulate system can be successfully designed for sustained delivery of saxagliptin and to improve dosage form characteristics for easy formulation .