Short Communication For reprint orders, please contact: reprints@future-science.com Stability and biological testing of taurine-conjugated bile acid antioxidant microcapsules for diabetes treatment Armin Mooranian 1 , Nassim Zamani 1 , Momir Mikov 2 , Svetlana Goloˇ corbin-Kon 3 , Goran Stojanovic 4 , Frank Arfuso 5 & Hani Al-Salami* ,1 1 Biotechnology & Drug Development Research Laboratory, School of Pharmacy & Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, 6102, Australia 2 Department of Pharmacology, Toxicology & Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Novi Sad, 21101, Serbia 3 Department of Pharmacy, University of Novi Sad, Novi Sad, Serbia, 21101 4 Centre for Integrated Microsystems and Components, Laboratory for Microelectronics, Faculty of Technical Sciences, University of Novi Sad, Novi Sad, 21101, Serbia 5 Stem Cell & Cancer Biology Laboratory, School of Pharmacy & Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, 6102, Australia *Author for correspondence: Tel.: +61 8 9266 9816; Fax: +61 8 9266 2769; hani.al-salami@curtin.edu.au Aim: Taurine-conjugated bile acids possess positive formulation-stabilization effects, which are desirable in diabetes treatments. The taurine-conjugated bile acid, taurocholic acid (TCA), has shown promising formulation-stabilizing effects on the delivery of the antioxidant drug, probucol (PB), but success is limited due to its poor release profile. This study aimed to design new PB-TCA formulations using new polymers, and examine antioxidant and antidiabetic effects using β-cells for PB with or without TCA. Materials and methods: Different formulations using alginate-insoluble esters of polymethylacrylate polymers encapsu- lating PB and TCA were developed, microencapsulated and examined for stability and biological activity. Results: TCA addition to new PB matrices improved osmotic and mechanical properties, and this effect was dependent on polymethylacrylate composition and concentration. Conclusion: TCA can optimize the oral delivery of anti-diabetic compounds. First draft submitted: 24 May 2018; Accepted for publication: 16 January 2019; Published online: 6 February 2019 Keywords: diabetes mellitus • eudragit • microencapsulation • oral delivery • probucol • taurocholic acid Conjugation of bile acids is a process in which an amino acid (taurine or glycine) is chemically attached to the carboxylic group moiety, and results in primary, secondary or tertiary bile acids. The conjugation process is part of bile acid metabolism and takes place in the liver by hepatocytes [1]. The conjugated bile acids (CBAs) are secreted from the liver into the gall bladder to form the bile, which flows into the upper part of the intestine to assist with food digestion [2]. Bile is released into the intestine multiple times a day and the CBAs are deconjugated by gut microflora to form deconjugated bile acids that are metabolized and reabsorbed back from the gut into the liver via the systemic circulation. The processes of bile acid production by the liver and flow to the gall bladder, their conjugation, deconjugation, metabolism and reabsorption from the gut are known as the enterohepatic recirculation, and it takes place in cycles, averaging 12-times every day in humans [3]. Bile contents and the bile acid pool have been shown to be significantly altered during development of chronic diseases such as diabetes mellitus (DM) [4,5]. DM has two main types, Type 1 diabetes (T1D) and Type 2 diabetes (T2D). T1D occurs when the immune system destroys our own pancreatic β-cells due to falsely identifying the cells as xenobiotics. On average, T1D affects 10% of the diabetic population, while T2D is the most common type of DM and affects 90% of the diabetic population. T2D has been associated with a disturbed lipid profile and high levels of oxidants and free radicals, inflammation and alteration in gut physiology and bile acid metabolism [6–8]. Although there are more than 100 bile acids in the human body, only a small number have been fully investigated for their applications in medical research and potentials a therapeutics in DM therapy. Examples of CBAs that have Ther. Deliv. (2019) 10(2), 99–106 ISSN 2041-5990 99 10.4155/tde-2018-0034 C  2019 Newlands Press