Applicability of a New Modified Calcium Starch as Release Retarding Polymer: A Comparative Study

This chapter evaluate the drug release retarding efficiency of a newly modified starch named calcium starch, in comparison to known polymers namely hydroxy propyl methyl cellulose (HPMC), sodium carboxy methyl cellulose (sodium CMC), ethyl cellulose and olibanum gum. Controlled-release dosage forms have made significant progress in terms of clinical efficacy and patient compliance. Drug release from the systems should be at a desired rate, predictable and reproducible. Polymers, which are used as release retarding materials in the design of controlled-release dosage forms play a vital role in controlling the delivery of drug from these dosage forms. Gliclazide (30 mg) matrix tablets were created using calcium starch and the other polymers at a polymer content of 5%, and the tablets underwent testing. All of the calcium starch- and other polymer-based matrix tablets slowly released gliclazide over a period of 12 to 24 hours. The release mechanism for each of the prepared matrix tablets was found to follow non-fickian diffusion. The release of Gliclazide from the matrix tablets made with hydroxy propyl methyl cellulose, ethyl cellulose, sodium CMC, and olibanum gum was relatively quick, and it was finished in 12hrs. But matrix tablets prepared with calcium starch, gliclazide release was slow and spread over 24 hours. The drug release was relatively rapid in the case of sodium CMC, olibanum gum, ethyl cellulose and HPMC (98%- 99%) and the release was completed within 8 – 12 hours with these tablets. In contrast, calcium starch caused the gliclazide release to be gradual and spaced out over 24 hours.