Synthesis and Preliminary Characterization of Polyurethane Matrices Used as a Drug Carrier for Bromelain

Bromelain, a natural substance sourced from pineapples, was found effective in various colds, in preventing heart attack and respectively in excess weight. On the other hand, it is well-known that pineapples juice increases the gastric acidity and respectively the people with hemophilia, internal bleeding must also be very careful in consuming this fruit. The objectives of this study were to obtain and to characterize a drug delivery system used for the transmembrane transfer of bromelain. The samples based on polyurethane matrices with and respectively without bromelain were synthesized and characterized by measurements of pH, encapsulation efficacy, cumulative drug release in a degradative media and in simulated gastric acid, electron microscopy and by modern techniques such as Zetasizer, cytotoxicity assay, and various non-invasive skin irritation assessment. The results indicate the obtaining of polyurethane matrices with mean sizes between 322-342 nm and neutral pH, that have a medium stability against the clusters formation tendency and a medium drug release rate. The non-irritative potential and the results on their cytotoxicity are important evidences that can be used for the further clinical trials of the polyurethane carriers.