Insight into Water Structure at the Surfactant Surfaces and in Microemulsion Confinement.

Interactions with surfactant molecules can significantly alter the structure of interfacial water. We present a comparative study of water-surfactant interactions using two different spectroscopic approaches: water at planar surfactant monolayers by sum frequency generation (SFG) spectroscopy and interfacial water confined in reverse micelles formed by the same surfactants using IR absorption spectroscopy. We report spectral features in the OH-stretching region (3200-3700 cm) that are observed in both IR and SFG spectra, albeit with different relative amplitudes, for ionic surfactant sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT) and nonionic surfactant polyoxyethylene(4)lauryl ether (Brij L-4) reverse micelles in hexane and the corresponding monolayers at the air/water interface.

Imitation of biomembranes on the basis of cholic acid and endogenic thermostable protein complex in biopartitioning micellar chromatography.

The structure of biomembranes was imitated by introducing nonionic surfactant polyoxyethylene (23) dodecylether, cholic acid and endogenic thermostable protein complex (14-65 kDa) into the mobile phase. The influence of concentration of these additives on the retention of the model compounds was studied. The competing interaction of cholic acid and endogenic thermostable protein complex in the lipid bilayer model was revealed on the basis of chromatographic data.

Study of chromatographic characteristics of inorganic analytes in biopartitioning micellar chromatography with ion-pair additives.

The chromatographic behavior of model ions of biomedical and environmental significance was investigated by using nonionic micellar mobile phases modified with ion-pair additives. The influence of concentrations of polyoxyethylene (23) lauryl ether and ornithine hydrochloride in the mobile phase on the retention factors of chromium (III), chromium (VI), iodide and bromide ions was studied. The possible mechanisms of retention of the mentioned ions in biopartitioning micellar chromatography with zwitter ion-pair additives were proposed.

Study of influence of additives of tyloxapol on the chromatographic characteristics of the model compounds: the comparative characterization of micellar mobile phases of tyloxapol and Triton X-100.

The chromatographic behavior of model compounds of biomedical significance (organic acids, amino acids, drugs) was investigated using mobile phases modified with tyloxapol. The influence of factors such as concentration of tyloxapol, content of organic modifier and pH of mobile phase on the retention factor of solutes was studied. The results were compared with the data obtained by elution with mobile phases containing Triton X-100 additives, since units of Triton X-100 are repeated in the structure of tyloxapol.

Imitation of artificial membrane system via mobile phases with Tween-80 and cholic acid in biopartitioning micellar chromatography.

The chromatographic behaviour of compounds of biomedical significance was studied using micellar mobile phases modified with polyoxyethylene (20) sorbitan monooleate (Tween-80). The influence of the surfactant within the 0.75-4% concentration range on the retention factor of model compounds was investigated.

Investigation of artificial biomembrane systems in biopartitioning micellar chromatography by method of mathematical design.

An attempt to create and study an artificial membrane system was realized via biopartitioning micellar liquid chromatography. Towards this end the known formula of membrane permeability (on the basis of Fick's diffusion equation) was modified so that membrane permeability may be estimated in terms of chromatographic characteristics. The two-factoral experiments on the basis of mathematical design of second order were carried out.

Interaction of surface-active drugs in rabbits.

The interaction of chlorpromazine and promethazine in vivo has been investigated. The drugs were administered to the rabbit orally as a single dose (100 mg of each drug) as well as simultaneously with an interval of 15 min. The presence of multiple peaks at the separate administration of promethazine and chlorpromazine on the one hand, and increase of number of peaks, symbathic character of kinetic curves of mentioned drugs and its prolonged appearance in the systemic circulation of the blood by simultaneous administration on the other hand, may be explained by the intensive presystem metabolism and surface-activity ability of these drugs, and by the periodic 'lassitude' of liver for their capture and elimination (either presystem or systemic).

The study of growth inhibitive protein factor by various mode of HPLC and estimation of its binding with drugs.

The protein fraction of the brain of white rat inhibiting the proliferation of homological cells was studied by hydrophobic interaction and reversed-phase liquid chromatography. The hybrid modification of hydrophobic interaction and biopartitional micellar chromatography was also applied for the elution of hydrophobic component of brain protein fraction. It was established that this protein fraction represents a hydrophilic-hydrophobic complex.

Influence of nonionic surfactants on the chromatographic behaviour of proteins in hydrophobic interaction chromatography.

The chromatographic characteristics of proteins in the presence of additives of nonionic surfactants Brij-35 and Tween-80 in the conditions of descending gradient of ammonium sulfate and phenyl-coated polymeric stationary phase were investigated. It was revealed that retention factors of proteins may be regulated by use of mentioned additives. The improvement of resolution is achieved for some hardly separated pairs of proteins, viz.

Interaction of carbamazepine and promethazine in rabbits.

The interaction of carbamazepine and promethazine in rabbits has been investigated. The influence of this interaction on the processes of biotransformation in the liver was revealed. The drugs were administered as single oral doses (100 mg of each drug) as well as simultaneously with an interval of 15 min.

Determination and pharmacokinetic study of ferrocene-A in blood serum of rabbits.

Ferrocene-A (ferrocenyl-1-phenyl-1-dioxy-1,4-butin-2) has significant antitumour and antibacterial properties. This study was designed to estimate main pharmacokinetic parameters of ferrocene-A (FC-A). These parameters are very important from the standpoint to elucidate the mechanism of pharmacological action of ferrocene-A.