Encapsulation efficiency and in-vitro dissolution tests of nifedipine microcapsules coated by poly(L-lactic acid) and poly(ethylene glycol) poly blend

Cardiovascular disease is the leading cause of death globally. Cardiovascular diseases such as coronary arteries, strokes and peripheral arterial disease involve atherosclerosis, a condition in which the inside of the arteries narrows due to plaque buildup. One of the cause of atherosclerosis is high blood pressure. Nifedipine is a drug used in the treatment of cardiovascular disease caused by hypertension. Nifedipine is a high blood pressure-lowering drug that is insoluble in water and has low bioavailability. It is consumed 3 times a day. Consumption of drugs that are done repeatedly will increase the side effects of the drugs. Therefore a controlled drug delivery system is needed to increase the bioavailability of the drug. Microencapsulation method using biodegradable polymers is an alternative choice to achieve it. In this study, two types of biodegradable polymers poly(L-Lactic Acid) (PLLA) and poly(Ethylene Glycol) (PEG) were selected as coating materials for the encapsulation of nifedipine. Surfactants Tween 80 and Span 80 were also used in the formation of microcapsules to increase its stability. Based on the optimization of PLLA:PEG poly blend composition, the best results were obtained, which is 60:40 (w/w), with percent encapsulation efficiency and percent drug release of 72.68% and 18.17% respectively. The low dissolution result compared to the commercial nifedipine is caused by several factors including the relatively high crystallinity of PLLA so that it strongly coats nifedipine and the role of PEG as pore opening agent which is not optimal. These results were supported by X-Ray Diffraction (XRD) analysis and Scanning Electron Microscope (SEM) to observe the morphology of microcapsules.