The evaluation of activity and stability of isolated bromelain from pineapple cores (Ananas comosus [L.] Merr) and in vitro penetration test of nanoemulsion topical base

Objective: Oral administration of bromelain as an anti-inflammation therapy still faces several challenges, such as the risk of contact with the gastric fluid and its low absorption rate. Therefore, bromelain isolated from the pineapple core will be formulated as a topical base in a nanoemulsion to increase its stability, activity, and ability to penetrate the skin. Methods: Bromelain was isolated from pineapple core using ammonium sulfate precipitation and dialysis, and then the isolated fraction was loaded into topical nanoemulsion for subsequent evaluation of its characteristics, stability, enzymatic activity, and for in vitro study of penetration using Franz diffusion cell. Results: The highest specific activity of bromelain fractions found in ammonium sulfate concentration is around 20–50%. After being dialyzed, the bromelain fraction showed an increase in specific activity 2.78-fold as compared to crude extract. The characteristics of bromelain nanoemulsion showed a globule size of 21.37±1.8 nm with a polydispersity index (pdI) 0.323±0.049, oil in water (o/w) type, and the type of rheology was plastic flow. The nanoemulsion stability base was observed, and there was no phase separation after centrifugation. Bromelain in nanoemulsion base showed a proteolytic activity of 5.00 U/ml with a protein content of 154.28 mg/l. In vitro penetration studies using Franz diffusion cell for 8 h showed isolated bromelain in nanoemulsion base has a total cumulative number value of 1386.94 μg/cm² with penetrated velocity/flux (J) of 45.93 μg/cm² h. Conclusion: The results showed promise for bromelain loaded into nanoemulsion as a vehicle for topically administered therapeutic enzymes.