full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and PharmacyVol. 5 (2) 1084-1097 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1084Integrity and Bioactivity of Insulin Loaded PLGA NanoparticlesPrepared by a Novel Aquesou Method and its Comparison toEmulsion Solvent Evaporation MethodMahmoud M. Ibrahim, 1,2 Omaima A.Sammour, 3 Mohamed Hammad, 2Nagia A. Megrab 2 , Xiaoling Li 1 and Bhaskara Jasti 1*1Thomas J. Long School of Pharmacy and Health Sci, University of the Pacific, Stockton, CA, USA2Dept. of Pharmaceutics, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt3Dept. of Drug Technology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt*For Correspondence -bjasti@pacific.eduAbstractPoly lactic-coglycolic acid polymernanoparticles of insulin were prepared by a novelaqueous based mixed micelle (MM) method andtraditional emulsion solvent evaporation methodthat use organic solvents. The particle size andentrapment efficiency and insulin release fromthe nanoparticles were determined. The integrityof the entrapped insulin, bioactivity andimmunogenicity were investigated using MALDIMS, cell viability assay, and ELISA tests. Thepharmacodynamic activity of the entrapped insulinin nanoparticles was compared with itssubcutaneous administration in diabetic rats. Thenanoparticles released 50% of insulin immediatelyat pH 7.4, followed by slow release of theremaining entrapped insulin. At pH 1.2, completerelease of insulin occurred within 5 minutes. At apH closer to PI of insulin, the burst releasedecreased to 8%. The molecular mass, cellviability and Elisa test showed that insulin retainedits integrity and activity. The blood glucose levelsin rats showed sustained reduction following theadministration of insulin loaded nanoparticlessuggesting that insulin activity in nanoparticlesprepared by MM and ESE methods has remainedintact.Keywords: Bioactivity, Immunogenicity, Insulinintegrity, Mixed micelle, NanoparticlesIntroductionRecently, considerable progress has beenmade in developing biodegradable nanoparticlesas effective vehicles for the delivery of proteinsand peptides (1). These polymer drug deliverysystems offer many advantages as they can carryand deliver the drug to a target site, have the abilityto deliver proteins, peptides and genes, increasethe therapeutic benefits and minimize the sideeffects of the drug (2,3). Also, they can controlthe release of a pharmacologically activecomponent at the therapeutically optimal rate anddose regimen and help to increase the stability ofdrugs and proteins (4,5). The PLGA polymers,being biocompatible, have been used as controlledrelease delivery systems for parenteral andimplantable applications (6). A successful PLGAnanoparticulate system should have a high drugloading capacity as it allows a small quantity ofthe carrier during a single administration. Insulinis the most effective drug in the treatment ofadvanced-stage diabetes. Despite the significantadvancement in the field of pharmaceuticalresearch, development of a proper insulin deliverysystem remained a challenge (7). The biologicalhalf life of peptides is short and need frequentand multiple administrations. Their transportacross biological barriers is also poor, due to poordiffusivity and lower partition coefficients. In thisIntegrity and Bioactivity of Insulin Loaded PLGA