Moisture induced solid phase degradation of l-ascorbic acid part 3, structural characterisation of the degradation products

Thermal and mechanical properties of polyurethanes modified with L-ascorbic acid

“…Thermal stability is of particular interest, because of the thermal decomposition kinetics studies, which may lead to improvement in ascorbic acid stability, which is important especially considering the context of pharmaceuticals, food products [18], and recently medical devices, modified with ascorbic acid [23,24]. In the literature are available degradation studies of ascorbic acid, carried out under different conditions, such as in different solvents [30], in steam [31], in food [20], under oxygenated conditions [32] and under inert conditions [33]. To simulate physiological environment or storage conditions, researchers performed studies under invariable temperature and below 100°C.…”

“…References report a number of instrumental methods, such as differential scanning calorimetry, differential thermal analysis, and thermogravimetric analysis, which may be used to determine the study of decomposition kinetics [18] and degradation products of ascorbic acid [31,32,34]. Jingyan et al investigated the thermal behavior of dry and solid ascorbic acid in a wide temperature range from -25 to 800°C.…”

“…Moreover, the degradation of solid AA is believed to follow at the different path than in solution. When 5 % v/w moisture was present in a solid ascorbic acid sample, the discoloration was observed, from white to dark brown [31]. Studies on decomposition kinetics of vitamin C in various food products under different storage and processing conditions revealed that decomposition of AA follows with first-order kinetics [25][26][27][28][29].…”

“…At the third stage, only slow carbonization process was observed. Some publications reports that the decomposition of AA leads to furan derivatives, in which furfural was considered as a main product [31,34].…”

Application of HPLC to assess the compatibility of bisoprolol fumarate with selected excipients in mixtures by isothermal stress testing

“…Degradation of BPL in presence of ASA is may be due to reaction with the degradation products of ASA. ASA undergoes solid state degradation in presence of moisture and forms furoic acid, tetrahydrofuran, furfural, 1-(2-furanyl)-ethanone and 1-(2-furanyl)-1-propanone [21,41], which may react with the BPL based on the study of structurally similar drug atenolol [21]. Degradation of BPL with BHA is may be due to reaction with the phenoxy radicals generated from BHA [42,43].…”