Abstract The aim of this study was to compare the specific characteristics of the S-enantiomer and the racemate of amlodipine besylate (AB) in order to design a robust and stable formulation of the active S-enantiomer which will guarantee continuous performance of the unichiral version of amlodipine. Preformulation studies showed that the S-enantiomer and the racemate exhibit different crystal morphology, particle size distribution and higroscopicity. The S-enantiomer exhibited significantly lower melting temperature compared to the racemate which was in accordance with its higher water solubility and its increased intrinsic dissolution rate. The thermograms of S-amlodipine besylate indicated that dehydration and melting occur at almost the same time and the dehydration event overlaps with the melting peak. Forced degradation tests conducted on both substances showed high levels of degradation into amlodipine related substance D as well as other impurities. Tablets prepared with S-AB, simulating originator’s formulation, failed in stability tests due to drug incompatibility with calcium hydrogen phosphate. Therefore, a tablet formulation based on excipients which were confirmed compatible with S-AB was developed and optimized using full factorial design to obtain a dissolution profile comparative to the brand product. Stability studies conducted at 40 °C/75% relative humidity (RH) confirmed that appearance, drug content and drug release of the optimized tablet formulation remained within the recommended limits.

Introduction: Several decades of basic science and animal research provided considerable support for significant role of plasma free fatty acids (FFAs) in etiology of Type 2 diabetes mellitus (T2DM). Contradicting data related to signifi cance of elevated FFAs in plasma of patients with Type 2 diabetes prompted us to study concentrations of palmitic acid, stearic acid, and linoleic acid, in patients and healthy controls in an attempt to possibly use them as potential biomarkers in progression of the disease. Since aging is associated withincreased plasma glucose and insulin levels that are consistent with an insulin resistant state, in this study,age differences in the concentration of the above mentioned acids were tested.Methods: Progressive changes in their concentrations were followed through a period 6 months. All subjects included in the study were free of evidence of hepatitis B or C viral infection or active liver and kidney damage. Analysis of glucose and glycated hemoglobin levels were performed on BT PLUS 2000 analyzer using standard IFCC protocols, while concentrations of FFAs were analyzed by gas chromatography.Results: Our data demonstrated signifi cantly higher FFA values in plasma of diabetic patients as compared to healthy controls. There was a trend of correlation of FFAs levels with the blood glucose levels in diabetic patients, which was more prominent in diabetic men than in women.Conclusion: With aging, levels of free fatty acids signifi cantly increased in plasma of diabetic patients, and this effect was also more profound in male than in female diabetics.