Dissolution study of bromelain resulting from partial purification of pineapple stem (Ananas comosus [L.] Merr) encapsulated in chitosan-guar gum and its activity as an antiplatelet

This research aims to maintain the antiplatelet activity of bromelain as a result of isolation from degradation in the stomach environment by encapsulating it in chitosan-guar gum hydrogel matrix cross-linked with glutaraldehyde to ensure the targeted drug release in the intestine environment. Bromelain enzyme isolation from pineapple stem was done through several steps which were extraction, fractionation with ammonium sulphate, and dialysis. The specific activity of each fractions showed an increase, from crude enzyme (43.73 U/mg), fractionation with ammonium sulfate (369.01 U/mg), and dialysis (437.89 U/mg). Bromelain enzyme resulting from dialysis was then encapsulated in hydrogel matrix by post-loading to be tested for in vitro dissolution in artificial stomach and intestine environments. The hydrogel used was chitosan-guar gum with 3% (v/v) concentration of glutaraldehyde, with the swelling ratio of 75.83% and 68.39% in pH 1.2 and 7.4 respectively. The isolated bromelain concentration varied in each encapsulation process which were 20 mg/L, 40 mg/L, and 60 mg/L respectively so that an optimum encapsulation efficiency of 97.32% was obtained at 20 mg/L. Dissolution test results showed the maximum release of bromelain was relatively high in artificial intestine environment (73.53%) compared to stomach environment (19.11%) with a maximum proteolitic activity of 0.43 U/mL and 0.18 U/mL in artificial intestine and stomach environment respectively. Dissolution results were then inserted into zeroth-order, first-order, Higuchi equation, and Korsmeyer-Peppas equation mathematical models to determine the drug dissolution mechanism by Fickian diffusion. Antiplatelet test showed a good inhibition percentage towards dialysis enzyme (46.60%) and dissolution solution (41.31%).