Capillary zone electrophoresis to study the hydrolytic degradation of a novel gluconic/glycolic/lactic acid copolymer

Abstract

A typical member of the novel family of hydrolytically degradable aliphatic polyesters resulting from the copolymerisation of (3-(1,2-3,4-tetraoxobutyl-diisopropylidene)-dioxane-2,5-dione) (DIPAGYL) and racemic lactide under powder form was allowed to degrade in phosphate buffer saline at 55°C. Capillary zone electrophoresis was used to monitor the water-soluble derivatives present in the ageing medium. Indirect UV detection using p-anisate as the absorbing anion was described and the conditions to achieve quantitative determination were defined. The method was applied to monitor the fate of a couple of dimeric intermediates, namely lactyllactate and gluconylglycolate and glycolylgluconate. The method can also be used to evaluate the total amount of released compounds, despite the fact that higher water-soluble oligomers could not be detected because of a too short lifetime. Last but not least, it was proved that the copolymer did return to its ultimate building blocks, namely gluconic, glycolic and lactic acids.