OBJECTIVE:Implementation of the control method to validate previously obtained calibration functions according to GOST R ISO 11095-2007 using Reference Materials (RM): standard RMs - aqueous solutions of ethanol, produced and certified by the organization, and internal RMs - aqueous solutions of ethanol in different concentrations, developed by the user for internal use. MATERIAL AND METHODS:We applied the control method in accordance with the National Standard of the Russian Federation GOST R ISO 11095-2007 using the standard and internal RMs - aqueous ethanol solutions in different concentrations. Measurements were performed for two subranges of ethanol concentrations on standard and internal RMs in accordance with the certified method. RESULTS AND CONCLUSION:Control charts based on experimental data confirmed that the system was in a controlled state, and the calibration function required no updates on Day 7. No studied values fell outside the upper and lower control limits on the control charts. The uncertainty of the transformed values was assessed during the calibration function validation.

OBJECTIVE:To assess the adequacy of linear function of calibration according to GOST R ISO 11095-2007 for ethanol mass concentration measurement using internal reference materials (RMs).MATERIAL AND METHODS:An experiment on calibration in accordance with the GOST R ISO 11095-2007 National standard of the RF was carried out using internal RMs, namely aqueous solutions of ethanol at different concentrations. Measurements were performed for two subbands of ethanol concentrations at RMs: 0.15-1.05 and 1.0-7.0 mg/ml - according to the certified methodology.RESULTS:The graphs of the calibration's functions based on experimental data are consistent with the assumption of the calibration function's linearity, as well as the assumption of the standard deviation's constance of residues is equitable for two subbands of RMs.CONCLUSION:Proven linear models in the calibration experiment may be recommended for use in the ethanol mass concentration measurement.

Grafted copolymers of chitosan–vinylpyrrolidone, water-soluble at a pH of 6.8–7.5, were obtained. A technique has been developed for obtaining an aggregatively stable system of platinum nanoparticles in copolymer solutions with an average size of 4 nm. The thermophysical and structural characteristics of the powdered composition of a platinum nanoparticle-copolymer are investigated. An in vitro comparison of the antitumor activity of solutions of the developed composition and cisplatin at the same platinum concentration was performed. It was found that with respect to the culture of HeLa Kyoto and A431 cancer cells, the composition is five and two times less effective than cisplatin, respectively. Along with this, the biocompatibility of the composition is 17 times higher than that of cisplatin, which allows its use at elevated concentrations and the development of an antitumor agent with platinum nanoparticles commensurate in effectiveness with cisplatin.

Block copolymers based on fish collagen and chitosan were obtained by ultrasonic irradiation of a blend of homopolymers. The molecular weight of the block copolymer was 310 kDa. The tensile strength of the block copolymer film increases by more than 200

Alcohol extracts from the herb of Glycyrrhiza glabra L. were studied by HPLC on a Supelco Analytical C18 chromatographic column (4.6 mm × 15 cm, particle size 5 μm) eluted with a mobile phase of 0.1

Gas transport and physico-mechanical properties of synthesized films based on modified starch and chitosan have been studied. The values of the permeability coefficients of pure gases included in the air for films based on modified chitosan and a copolymer based on modified starch and chitosan at a temperature of 23°C were determined. The oxygen permeability coefficient of the synthesized copolymer was compared with other polymers. A copolymer based on modified starch and chitosan was found to have medium oxygen barrier properties. The biodegradability of the samples under the action of the micromycete Aspergillus niger was studied by analyzing the degradation products by chromatography-mass spectrometry. The total biodegradation time of the samples was 4 weeks. These films are promising for use as packaging material.

Abstract The structure, tensile strength and thermo-physical properties of chitosan films reinforced by TiO2 nanoparticles and obtained from aqueous solutions of various acids - hydrochloric acid, acetic acid, and lactic acid - were investigated. The TiO2 nanoparticles concentration was from 0.5 to 10 wt.% relative to the chitosan weight. The tensile strengths of all chitosan films prepared from aqueous solutions of acetic acid and hydrochloric acid containing TiO2 nanoparticles were greater than 80 MPa, while this characteristic for initial chitosan was approximately 35 MPa. The highest tensile strength was 127 MPa with an elongation of 13% was found for samples with TiO2 concentration 0.5 wt.% and obtained using acetic acid. These effects can be attributed to changes in the film structure when TiO2 small amount was added to it which was confirmed by IR-spectroscopy, X-ray diffraction analysis, scanning electron microscopy and atomic force microscopy. A glass transition temperature increasing of the samples were determined in the TiO2 presence. Moreover, the films exhibited antibacterial activity against Staphylococcus aureus and were able to biodegrade.

Biodegradable starch-based composite material with bactericidal properties was obtained in this work. The material is promising as environmentally safe food packaging. Native potato starch was modified by graft polymerization of vinyl acetate. The synthesis was carried out in the presence of ammonium persulfate in the alkaline medium under a temperature change mode from 70 to 80 °C. The grafting efficiency was 82

Biodegradable polymer composite materials (PCM) based on modified starch and chitosan were obtained. Starch was modified by graft polymerization with acrylamide, chitosan with enanthaldehyde with the formation of Schiff bases, which ensured the combination of polysaccharides in an aqueous solution in the pH range of 3.5–5.8. The physicochemical and structural properties, as well as the biocompatibility and biodegradability of PCM were studied. The films based on modified polysaccharides are characterized by increased strength characteristics compared to the parent components. With the weight ratio of the starch/acrylamide grafted copolymer and chitosan being equal, the ultimate tensile strength of the composite films was 65 MPa at a strain of 11

Platinum nanoparticles were obtained chemically in acetic acid solutions of chitosan from the precursor H2PtCl6 using sodium borohydride as a reducing agent with simultaneous UV irradiation. The compositions were studied by SAXS, TEM, dynamic light scattering, FTIR-spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and atomic force microscopy. Nanoparticles are characterized by a narrowly dispersed size distribution while the effect of the conformation of chitosan macromolecules on their characteristics is manifested. The SAXS method showed that in a chitosan solution with a semi-flexible coil conformation of macromolecules, 96.8 % of the formed nanoparticles are characterized by an average radius of 1.4 nm. According to the TEM results, platinum nanoparticles are characterized by a crystal structure and a particle diameter of about 1.3-5.0 nm. A different picture is observed for platinum nanoparticles formed in chitosan with the rigid rod conformation of macromolecules - only 91 % of platinum nanoparticles had an average radius of 1.4 nm. The TEM method showed these nanoparticles turned out to be about 1 nm in size, and they did not crystallize, but remained amorphous. The introduction of platinum nanoparticles into the polysaccharide matrix significantly shifts the glass transition temperature of chitosan toward lower values by 20 and 10 degrees C respectively, and increases the tensile strength of the composites by 35 MPa.

A native potato starch was modififi ed with vinyl acetate by graft polymerization in alkaline medium with pH 10 in the mode of temperature change from 70 to 80°C for 4 hours. The initiator of the process was ammonium persulfate (NH4)2S2O8. The conversion of vinyl acetate was 91,5%. The chemical structure of graft copolymer (Starch:Vinyl acetate) was confifi rmed by IR-spectroscopy. Composite materials of modififi ed starch and triethyl citrate with tensile strength of 24 MPa were obtained. Under natural environmental conditions, materials undergo biodegradation of 96% in 28 days.

The bioavailability of the tablet dosage form of pharmaceutical substance RU-891, i.e., 9-(3,4-dihydroxyphenacyl)-2,3-dihydroimidazo[1,2- a ]benzimidazole hydrobromide, was investigated. The main pharmacokinetic parameters were determined. The relative bioavailability index was estimated at 93.98%. No evidence of drug accumulation from an RU-891 270-mg tablet dosage form was detected in rabbits upon threefold administration at a dose of 23 mg/kg.

Optically transparent organic-inorganic terpolymers containing nanostructured poly (titanium oxide) (PTO or (≡TiO)n) in polymeric matrixes of poly (hydroxiethylmethacrylate) (pHEMA) and its copolymers with acrylonitrile (AN), 2-ethylhexyleacrylate, buthylmethacrylate, vinylbuthyl ether and exhibiting UV-induced reversible surface hydrophilization had been subjected by climatic tests in the Q-SUN Xe-2 light weathering chamber, which simulates the exposure of the material under ambient conditions for 20 months of its operation. Adhesion, physical-mechanical and thermal-physical properties of PTO-containing materials had studied before and after climatic testing. The materials retain the capacity for the one-electron transition Ti4+ + e‾ ⇆ Ti3+ under UV-irradiation after environmental testing, resulting in both photochromic properties and reversible surface hydrophilization. The photocatalytic activity of materials in stearic acid decomposition at terpolymer's surface of composition [(≡TiO)n]: [HEMA]: [AN] = 1:5:1 had proven.

To increase the surface hydrophobicity of organic-inorganic copolymers containing nanostructured polytanoxide, they were modifified with flfluorine-containing monomers which were introduced into the composition of the monomer mixture, followed by polymerization-polycondensation. The flfluorinated monomers used were 2,2,3,3,4,4,5,5-octaflfluoropentylacrylate, 1,1,1,3,3,3-hex aflfluoroisopropylacrylate, 2,2,3,3-tetraflfluoropropylmethacrylate. The surfaces of the synthesized terpolymers were examined by X-ray flfluorescence analysis and atomic force microscopy. The inflfluence of the nature of the third monomer on the content of titanium and flfluorine atoms in the surface layer and in the chips of the samples as well as on the topography of their surface was determined. The difference in the elemental composition affects the initial hydrophobicity of the samples surface and their ability to hydrophilize the surface under UV exposure. Terpolymers with 1,1,1,3,3,3-hexaflfluoroisopropylacrylate links exhibit the highest wetting angle - 102° - in the absence of UV exposure. However, the "hydrophobicity-hydrophilicity" switching mode is most clearly seen in the terpolymers with 2,2,3,3,4,4,5,5-octaflfluoropentylacrylate links when the wetting angle can be reversibly changed from 86° to 10°.

A biologically active composition of chitosan-selenium nanoparticles has been developed. Selenium nanoparticles are characterized by a clear bimodal size distribution: 2–3 and ~37 nm. The main active centers of complexation with nanoparticles are the amino and hydroxyl groups of chitosan. In experiments on culturing fibroblasts of the hTERT BJ-5ta cell line on sample films, high biocompatibility of the composition was shown. It was shown that the composition of chitosan-selenium nanoparticles has a corrective effect on the oxidative processes of the body, reducing the activity of free-radical oxidation in the blood of animals. This opens up prospects for the use of this complex in the composition of antioxidant and adaptogenic drugs.

A method to obtain a multilayer insulin-containing composition in a nanostructured form consisting of layers: gold-chitosan-insulin-chitosan nanoparticles was developed. The size of the fully formed multicomponent system was 178 nm.The outer layer of chitosan protects insulin from the damaging effects of low pH-medium and proteolytic enzymes of the gastrointestinal tract when the composition is taken orally. Chitosan simultaneously performs a transport function to deliver insulin into the bloodstream. In experiments on experimental animals with artificially induced type 1 diabetes, it was found that the effectiveness and duration of hypoglycemic action of the composition depends on the amount of insulin in the dose. The composition containing 50 IU of insulin per dose provides a rapid decrease glucose level in the blood and maintains it at the level of the intact group for 3 h. After 6 h the efficacy of the composition is comparable to that of insulin injection. A fundamentally important indicator of the effectiveness of the composition is a constant content of glycated hemoglobin in the blood within 10 days.

The aim of the study is the investigation of the pharmacokinetic properties of the RU-1205 compound, with previously identified kappa-agonistic and analgesic effects, at a single oral administration, as well as comparison of the relationship between its pharmacokinetic and analgesic properties. Materials and methods. Pharmacokinetic parameters of RU-1205 after the oral administration at the dose of 50 mg/kg were investigated using the method of High Performance Liquid Chromatography with determination of the concentration of the compound according to the previously constructed calibration schedule. The indices of the area under the pharmacokinetic curve, clearance, half-life, residence time of the drug molecule in the body, a total (apparent) volume of distribution, as well as the indicator of absolute bioavailability, were calculated. The tissue distribution and excretion of RU-1205 were studied. Potential metabolites of RU-1205 were predicted using the PALLAS 3.00 program. The study of the analgesic activity was carried out on a model of central somatogenic pain with electricalstimulation, with the dynamics assessment of the voltage amplitude of the corresponding reaction of the "tail-flick" reflex. Results. The compound under study is rapidly adsorbed from the gastrointestinal tract, reaching a maximum concentration by the end of the first hour of the study, and is determined in plasma within 12 hours. Its half-life is 17.7 hours. The absolute oral bioavailability is 37.3%. It was found out that the compound is withdrawn within 3-4 days. The main route of excretion is extrarenal. Biotransformation of a substance probably proceeds mainly with the formation of oxidized forms of the initial molecule by reactions of the first phase of metabolic transformation. The analgesic effect is long-lasting: it starts after 15 minutes and lasts for 12 hours with flattening of the curve by the 8th hour. Conclusion. When administered orally, the test substance undergoes a long process of elimination, has the greatest tropism for the elimination organs and undergoes active biotransformation processes in the body of animals. As a result of it, active metabolic products with an analgesic activity are, possibly, formed.

A quantitative determination method for drug substance RU-31, a derivative of a methoxyphenylimidazo - [1,2-α]benzimidazole possessing antimigraine activity, in biological samples was developed. This method has selectivity and high sensitivity sufficient to allow its use for pharmacokinetic studies of RU-31. The sensitivity of the method (detection limit) for RU-31 is 100 ng/mL; limit of quantitation, 500 ng/mL. The average measurement error is ≤15%.