Microencapsulation of Omeprazole by Lactobacillus acidophilus ATCC 4356 Surface Layer Protein and Evaluation of its Stability in Acidic Condition

The present study introduces a novel method for encapsulation of the acid-labile drug called Omeprazole using Lactobacillus acidophilus (L. acidophilus) ATCC 4356 S-layer protein. Before preparing the Omeprazole suspension, a series of preliminary studies were performed on the Omeprazole powder. For this purpose, some parameters such as melting point, IR spectrum, UV spectrum, and the particle size of Omeprazole powder were investigated. The size reduction process was done in order to achieve an ideal formulation. Ultimately, the resulting powder had an average particle size of 35.516 μm and it was almost uniform. After calculating the amount of S-layer protein required for complete covering of drug particles, the effect of different factors on the drug coating process was investigated with one factor at a time method. Then stability of coated Omeprazole was evaluated in acetate buffer (pH 5). Finally, the maximum coat of drug particles was determined using S- layer protein of Lactobacillus acidophilus ATCC 4356 at 25 °C for 2 h, shaking rate of 100 rpm and ratio of 2:1 for S-layer protein amount/Omeprazole Surface in Tris hydrochloride buffer medium (50 mM, pH 8). The coating of Omeprazole by the S-layer protein decreased the drug decomposition rate up to 2.223.