Formulation and In vitro Characterization of Novel Sustained Release Microballoons of Anti-hypertensive drug

The objective of the current investigation is to reduce dosing frequency and improve patient compliance by designing and systematically evaluating sustained release microballoons of Propranolol hydrochloride. An antihypertensive drug, Propranolol hydrochloride, is delivered through the microparticulate system using ethyl cellulose as the controlled release polymer. Microballoons were developed by the emulsion solvent diffusionevaporation technique by using the modified ethanol-dichloromethane co-solvent system. The polymer mixture of ethyl cellulose and Eudragit ® S100 was used in different ratios (1:0, 1:1, 2:3, 1:4 and 0:1) to formulate batches F1 to F5. The resulting microballoons were evaluated for particle size, densities, flow properties, morphology, recovery yield, drug content, and in vitro drug release behavior. The formulated microballoons were discrete, spherical with relatively smooth surface, and with good flow properties. Among different formulations, the fabricated microballoons of batch F3 had shown the optimum percent drug encapsulation of microballoons and the sustained release of the Propranolol hydrochloride for about 12 h. Release pattern of Propranolol hydrochloride from microballoons of batch F3 followed Korsmeyers-peppas model and zero-order release kinetic model. The value of ‘n’ was found to be 0.960, which indicates that the drug release was followed by anomalous (non-fickian) diffusion. The data obtained thus suggest that a microparticulate system can be successfully designed for sustained delivery of Propranolol hydrochloride and to improve dosage form characteristics for easy formulation.