Characterization and in vivo pharmacokinetic studies of polymer coated granules composed of chitosan microparticles containing didanosine

• Grant number: 06/06018-5
• Support Opportunities: Regular Research Grants
• Start date: January 01, 2007
• End date: December 31, 2008
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Maria Helena Andrade Santana
• Grantee: Maria Helena Andrade Santana
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

This research project involves the development of a new pharmaceutical formulation of the drug didanosine (ddI), which is used for the treatment of AIDS. In this new pharmaceutical formulation, didanosine is incorporated in polymeric chitosan microparticles. These microparticles are used of the preparation of granules, adequate for oral administration of the drug, through the use of a fluidized bed reactor. The advantagens of this new pharmaceutical formulation include: 1. It ensures the stability of didanosine in the gastrointestinal tract. 2. It promotes the adhesion of the microparticles to the intestinal membrane, which enhances the absorption and controlled release of the incorporated didanosine. 3. It is easy to handle and to swallow compared to the conventional form of the drug, especially for smaller children and the elderly. In previous studies, our group has successfully optimized the incorporation of didanosine in microparticles, tested various excipients for the formation of the granules, and performed and in vitro and ex vivo (inverted intestine) tests to analyze the mucoadhesive properties of the granules and release of ddI. This project includes the study and analysis two new aspects of the preparation process and final formulation of the drug, which include: 1. The production of the granules with the use of a Wurster type of fluidized bed reactor, and subsequent gastric resistant coating. 2. The pharmacokinetic plasmatic profiles of the produced granules in rats after oral administration. Statistical experimental design models from the program Statistica® will be used to study and evaluate the produced granules, in order to obtain the desired caracteristics.The gastric resistant coating of didanosine will be formed with the polymeric suspension of Kollicoat®, which will help prevent the deacetylation and drug degradation due to the gastric pH conditions. Pharmacokinetic plasmatic profiles in rats will be analyzed through no-compartimental and compartimental models using Excel 2002 (Microsoft) and Scientist v. 2.01 (MicroMath). The expected results are of great importance for the development of new processes and products for the benefit of human health. (AU)