and Ratna Asmah Susidarti, D. W. K. A. F. “Synthesis of Thiolated Chitosan As Matrix for the Preparation of Metformin Hydrochloride Microparticles”. Research in Pharmacy, vol. 2, no. 1, Oct. 2015, https://updatepublishing.com/journal/index.php/rip/article/view/256.