The characteristics of interactions of pharmaceuticals and their active ingredients with lipid membranes

Abstract

A comparative study of the effects of the active pharmaceutical ingredients of amixin, aspirin, metronidazole, phenibut, and fenspiride, as well as corresponding pharmaceuticals on lipid membranes was carried out. Lipid membranes of L-α-dipalmitoylphosphatidylcholine and native carp spermatozoa were used as models. A decrease in the melting temperature of L-α-dipalmitoylphosphatidylcholine membranes in the presence of all active ingredients and pharmaceuticals was found using differential scanning calorimetry. The only exception was the group of phenibut, where a splitting of the melting peak was observed. It was found that in the pharmaceuticals studied the active pharmaceutical ingredients exhibit a determinative membranotropic effect, whereas excipients play a modulating role. Changes in the parameters of water νОН bands in the L-α-dipalmitoylphosphatidylcholine membranes containing active pharmaceutical ingredients were quantitatively characterized by Fourier transform infrared spectroscopy. According to these parameters, the effect of the phenibut group differed in these parameters from that of the other ingredients. The changes of νОН bands caused by excipients were elucidated. An increase in the permeability of carp sperm cell membranes to water was observed in vitro for pharmaceuticals that induced a decrease in the phase transition temperature of a model membrane (amixin) and lipid lateral phase separation (phenibut).