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 calledOmeprazole using Lactobacillus acidophilus (L. acidophilus) ATCC 4356 S-layer protein. Beforepreparing the Omeprazole suspension, a series of preliminary studies were performed on theOmeprazole 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 reductionprocess was done in order to achieve an ideal formulation. Ultimately, the resulting powder hadan average particle size of 35.516 μm and it was almost uniform. After calculating the amountof S-layer protein required for complete covering of drug particles, the effect of different factorson the drug coating process was investigated with one factor at a time method. Then stability ofcoated Omeprazole was evaluated in acetate buffer (pH 5). Finally, the maximum coat of drugparticles was determined using S- layer protein of Lactobacillus acidophilus ATCC 4356 at 25 °Cfor 2 h, shaking rate of 100 rpm and ratio of 2:1 for S-layer protein amount/Omeprazole Surfacein Tris hydrochloride buffer medium (50 mM, pH 8). The coating of Omeprazole by the S-layerprotein decreased the drug decomposition rate up to 2.223.