Inclusion complexes of nifedipine and other 1.4-dihydropyridine derivatives with cyclodextrins. IV. The UV study on photochemical stability of the inclusion complexes of nisoldipine, nimodipine, nitrendipine and nicardipine with beta-cyclodextrin in the solution.
The results of measurements of photochemical stability of the inclusion complexes formed by nimodipine (NM), nisoldipine (NS), nitrendipine (NR) and nicardipine (NC) with beta-cyclodextrin (beta-CD) are reported. The inclusion complexes were obtained in solution. The formation of inclusion complexes in the liquid phase was estimated from a phase solubility diagram. The analysis of solubility curves in the phase diagram permitted calculation of stability constants of the inclusion complexes formed. Photochemical stability of 1.4-dihydropyridine derivatives obeyed the 1 order kinetic equation. The photodegradation of NM, NR and NC was found to be a single stage reaction. The photodegradation of NS occurred in two stages. In the inclusion complexes the photosensitivity of all studied DHP derivatives decreases. The complexation with beta-CD improved their photostability by 5-10 times. The greatest decrease in the photodegradation rate was observed for the most photosensitive compound NS whose photostability increased 100 times when in inclusion complex with beta-CD.
Mielcarek
J
J
Department of Inorganic and Analytical Chemistry, K. Marcinkowski University of Medical Sciences, Poznań, Poland.
D002121:Calcium Channel Blockers / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D004355:Drug Stability; D009529:Nicardipine / Q000737:chemistry*; D009553:Nimodipine / Q000737:chemistry*; D015737:Nisoldipine / Q000737:chemistry*; D009568:Nitrendipine / Q000737:chemistry*; D010777:Photochemistry; D047392:beta-Cyclodextrins
D002121:Calcium Channel Blockers; D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D015737:Nisoldipine; D009553:Nimodipine; D009568:Nitrendipine; D009529:Nicardipine; C031215:betadex