A team of researchers including Talib Hussain, Khizar Abbas and Zeshan Javaid from Hajvery University, Lahore, Pakistan and other universities have worked on the design of various solid matrix formulations of Gliclazide from mixtures of Glyceryl monostearate (GMS) and Stearic Acid (SA) in different ratios of drug to polymer and polymer to polymer, by hot melt method. Gliclazide is used for the treatment of non-insulin dependent diabetes mellitus (NIDDM). In this study, they used GMS and SA to control the release profile of the drug.
Sustained release compositions for medication are used for the uniform release of drug over an extended period of time in a day. They are gaining fame due to their controlled delivery rates and use for chronic diseases or for drugs with narrow therapeutic indices. One of the sustained release drug delivery systems include matrix system in which drug is homogenously distributed throughout a solid polymer.
Researchers have found that by increasing the amount of rate retarding polymer (GMS) in the matrix system, drug release rate decreased. On the other hand, by increasing the amount of SA in the matrix, increased the drug release rate. They have also found that the zero order kinetic model best supported the release data of many solid formulations as many of them followed Higuchi or zero order kinetics. Drug release, from the matrices, follows both the diffusion as well as erosion process. They showed that the polymers and drug have no interaction, with the use of Fourier Transform Infrared spectroscopy, while the drug and the polymer both were in amorphous state in the matrix.
Talib Hussain, Tariq Saeed, Ahmed M. Mumtaz, Muhammad Jamshaid, Muhammad N. Aamir, Khizar Abbas, Zeshan Javaid & Azeema Awais, (2011). Development of Gliclazide Matrix Tablets from Pure and Blended Mixture of Glyceryl Monostearate and Stearic Acid. Latin American Journal of Pharmacy, 30 (8): 1475-80