Capillary electrophoresis as a screening tool for alpha amylase inhibitors in plant extracts

Capillary electrophoresis [CE] method was developed for screening plant extract for potential alpha amylase [AA] inhibitory activity. The method was validated against a well established UV method. Overall, the proposed method was shown able to detect plants with significant alpha amylase inhibitory activity but not those with rather clinically insignificant activities. Fifty plant species were screened using both the proposed CE method and the UV method and seven plant species were found to possess significant AA inhibitory activities. Two plant species were proved to have alpha amylase inhibitory activity for the first time

Acarbose binding to human serum albumin studied by affinity capillary electrophoresis

The equilibrium interaction between acarbose and albumin was studied using affinity capillary electrophoresis. The migration time of albumin was shown to increase as a result of increasing concentration of acarbose within the sample. Peak area of albumin was decreasing as a result of acarbose binding. The progressive decrease in peak area associated with increasing acarbose concentration was employed to obtain Scatchard plot and consequently the binding constant. The estimated binding constant was 6.7 x 10[-4] M[-1]. The rather unexpected increase in migration time of albumin as a result of acarbose binding was explained in terms of potential change in the three dimensional structure of albumin. Such structural changes might facilitate the binding of other compounds such as digoxin. Therefore, these findings might explain the frequently reported decrease in free digoxin concentration when given concomitantly with acarbose

Investigation of drug polymer interaction: evaluation and characterization of diclofenac-chitosan co-precipitate

Investigating the interaction between Diclofenac and Chitosan and its effect on the dissolution in water and in Phosphate buffer system was the objective of this study. Complex formation was attempted between diclofenac and chitosan utilizing optimal condition for their simultaneous ionization in solution form. A co-precipitate was obtained upon mixing the drug and polymer solutions and the co-precipitate was characterized for drug content, differential scanning calorimetiy [DSC], X-ray diffraction and infrared spectroscopy [FTIR] analysis in comparison to diclofenac sodium, diclofenac free acid and their physical mixtures with chitosan. The overall evidence of these comparisons indicated that a physical co-precipitation of chitosan and diclofenac acid was formed with no electrostatic complexation. Having diclofenac acid as a reference for comparison was the key for this conclusion, and comparing the results of the precipitate to only those of diclofenac sodium would have led to false conclusions. The no complexation between the drug and polymer could not be explained based on lack of ionization of either molecule and was explained based on the instability of the complex