Habib M J, Asker A F
College of Pharmacy and Pharmacal Sciences, Howard University, Washington, D.C.
J Parenter Sci Technol. 1991 May-Jun;45(3):124-7.
The influence of liposomes on the photostabilization of riboflavin in an aqueous formulation was studied under fluorescent light at various conditions. Liposomal composition, concentration, pH, and ionic strength were varied. The photostability of riboflavin was found to increase in the presence of neutral and negatively-charged liposomes but to decrease in association with positively-charged liposomes. Furthermore, increasing the concentration of dimyristoyl-phosphatidylcholine (DMPC) in the composition of the liposomes resulted in an enhancement in the photostability of riboflavin such that at 5.8mM DMPC concentration a 2.3 fold increase in photostability was observed compared to control buffer solution. The pH of the medium influenced the photostability of riboflavin. However, the ionic strength of solution appeared to demonstrate no significant effect. The photodegradation reactions appeared to follow first-order kinetics in the presence and absence of liposomes.
在不同条件下，于荧光灯下研究了脂质体对水性制剂中核黄素光稳定性的影响。改变了脂质体的组成、浓度、pH值和离子强度。结果发现，在中性和带负电荷的脂质体存在下，核黄素的光稳定性增加，而与带正电荷的脂质体结合时则降低。此外，增加脂质体组成中二肉豆蔻酰磷脂酰胆碱（DMPC）的浓度会导致核黄素光稳定性增强，以至于在DMPC浓度为5.8mM时，与对照缓冲溶液相比，光稳定性提高了2.3倍。介质的pH值影响核黄素的光稳定性。然而，溶液的离子强度似乎没有显著影响。在有和没有脂质体的情况下，光降解反应似乎都遵循一级动力学。
