Evaluation of in-vitro dissolution profiles of Partially Purified Bromelain from Pineapple Cores (Ananas comosus L. Merr) loaded in Glutaraldehyde-Crosslinked Chitosan Microspheres

摘要

Bromelain belongs to a group of protease enzymes which has function in the pharmaceutical field as an antiplatelet. The use of bromelain through oral administration is quite difficult because the enzyme is easily degraded by acidic stomach fluids and gastric enzymes. The bromelain must be encapsulated in glutaraldehyde-crosslinked chitosan microspheres (GCM) to maintain the activity of bromelain until it reaches the intestine. The aim of the study was to evaluate the dissolution profiles and in vitro antiplatelet activity of bromelain from partial purification of pineapple cores encapsulated in GCM. In this study, we isolated bromelain from pineapple cores by using ammonium sulfate precipitation and dialysis. Specific activities of each fraction showed an increase, ranging from crude enzymes (71.10 U/mg), ammonium sulfate fraction (151.70 U/mg) and dialysis (226.8 U/mg). By using a post-loading method, bromelain fraction from the dialysis step was encapsulated in GCM matrixes. GCM has a crosslinking degree of 94.87% and swelling ratio of 42.17% at pH 1.2; 21.90% at pH 7.4. The encapsulation efficiency of bromelain in GCM was 84.75%. Evaluation dissolution profiles of GCM-encapsulated bromelain were tested in artificial stomach fluid and intestinal environment for 10 hours. The results showed a relatively lower release rate of bromelain in artificial stomach fluid (13.43%) compared to the intestinal environment (60.52%). Proteolytic activity of bromelain could be maintained up to 0.35 U/mL in an artificial intestinal environment. FTIR and Scanning Electron Microscope are chosen for GCMencapsulated bromelain characterization. However, the GCM released bromelain satisfactorily, with at least 74% of the bromelain dissolved within 10 hours while in vitro antiplatelet activity using platelet-rich plasma showed a good inhibition percentage of 71.88%.