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The effect of the sodium salt of succinyl chitosan (SCTS) and the presence of modifying additives (ethanol and glycerin) on the kinetics of the release of a medicinal substance (MS) of dioxidine (DO) from the liquid dosage form is studied. It is found that the addition of ethanol to a liquid dosage form based on succinyl of chitosan is accompanied by a change in the viscosity characteristics of the polymer, which leads to a decrease in the amount of the MS retained by the polymer chain and an increase in the rate of DO released. The introduction of glycerol, on the contrary, leads to a decrease in the MS release rate and the diffusion coefficient, which is accompanied by an increase in the prolonging effect of the polymer on the release of the MS from the liquid dosage form due to the increase in the total viscosity of the system.

The aqueous solutions of chitosan, succinyl chitosan sodium salt, and carboxymethylcellulose sodium salt are studied by the rheological method. An increase in the polymer concentration in solution leads to a sharp increase in viscosity due to formation of the entanglement network, the transition of the polymer solution to the gel-like state, a sharp increase in the relaxation time, and the appearance of elasticity of solutions. These systems are characterized by time anomalies characterized by a hysteresis loop, the area of which depends not only on concentration but also on the rate of increase/decrease of the shear rate. Thixotropy is observed in the intermediate concentration range, where supramolecular structures are formed and the time required for their destruction is comparable to the time of the experiment. This makes it possible to regulate a number of properties of materials formed from solutions. According to DSC studies, the glass transition temperatures and the melting temperatures of films obtained from solutions of different concentrations are different. The tensile stress and the elastic modulus of film polymeric materials pass through a maximum corresponding to the polymer concentration at which the maximum degree of structuring is implemented while maintaining the fluidity.

The article deals with the method of the medical purpose materials creation with the controlled physico-chemical and mechanical deformation properties on the basis of water-soluble derivative of amino polysaccharide chitosan – succinamide chitosan. The essence of the method is the macromolecules aggregation processes regulation in the initial solutions by the injection of organic cosolvents – acetone and ethanol. It has been stated that in a mixed solvent succinamide chitosan molecules are not in the form of the isolated macromolecular balls but as the macromolecules interacting (aggregated) systems. It has been proved that the presence of cosolvents decreases the polymer macromolecule links capability to interact with an enzyme and increases physico-mechanical characteristics of the film materials.

Creating biodegradable polymer compositions is an urgent problem. In this research, the processing parameters and physicomechanical properties of materials based on secondary polypropylene and secondary polyethylene filled with plant-based fillers are studied. It is estimated that the introduction of a filler leads to an increase in the maximal torsion torque; the lowest resistance against filler introduction is observed in the use of secondary polyethylene. Similar regularities are observed during the study of the minimal torsion torque; however, in this case, the lowest resistance is observed for the sample of secondary polypropylene. It is shown that the introduction of 10–15 parts by the mass of the filler leads to an increase in the elastic modulus and an insignificant decrease in the values of rupture stress and elongation upon breaking.

The thixotropic properties of aqueous solutions of the following polysaccharides are studied: chitosan, its water-soluble derivative the sodium salt of chitosan succinamide, and the sodium salt of carboxymethyl cellulose. These polymers have been selected due to their physiological activity and the possibility of using them for biomedical purposes. Studying the effect of the polymer concentration on rheological behavior shows that if a dilute polysaccharide solution is taken for research, then the flow curve does not actually depend on the time of exposure to the shear strain; i.e., the system is thixostable and in equilibrium, in contrast to semidiluted solutions, which clearly demonstrate nonequilibrium and thixotropy. The solutions of the studied polysaccharides behave like thixotropic systems only in the concentration region where supramolecular structures are uniquely formed and the time required for their destruction is comparable with the experiment’s time.

Films obtained from aqueous solutions of chitosan succinamide sodium salt are studied. It is found that the process of water vapor sorption by polymer films proceeds in an anomalous mode and the diffusion coefficients of water and the dioxidine drug in the films depend on the thickness of the samples and the concentration of the polymer in the initial solution. It is assumed that the dependence of the diffusion coefficients on the film preparation conditions is determined by the difference in the supramolecular organization of the films formed under different conditions, as well as by the difference in the surface roughness of the films.

The rheological behavior of the water-soluble chitosan derivative chitosan succinamide in a solvent—modifying additive system (ethanol, ethylene glycol, glycerin, sorbitol) was studied to find the conditions for the formation of highly viscous gels suitable for creating semisolid dosage forms. It was found that in the presence of modifying additives of polyhydric alcohols (glycerol and sorbitol), the complex viscosity of chitosan succinamide solutions increases and earlier formation occurs of the spatial network of macromolecules, whose strength makes it possible to form yield stress systems. It was shown that in the range of chitosan succinamide concentrations in a solution of 7.0–10.0 wt %, the use of polyhydric alcohols glycerol and sorbitol with a concentration of 1.5–4.0 M allows producing systems suitable for use as a polymer base for semisolid dosage forms with rheological characteristics, corresponding to the optimum consistency of hydrophilic ointments in the temperature range from 20–40°C, that is, under conditions that reflect the storage and direct use of semisolid dosage forms.

The article is devoted to the development of new approaches to the creation of modern wound healing highly elastic films with good hemocompatibility based on a water-soluble chitosan derivative – the succinyl of chitosan. These trips are based on the use of plasticizers. It was established that chitosan succinyl, in contrast to chitosan, is capable of exhibiting insignificant forced-elastic deformation, but still not sufficient to use unmodified films based on it as wound healing coatings. The deformation-strength properties of the films were studied on a universal tensile testing machine. The tensile stress (σ) was determined taking into account the cross-sectional area of the sample taken for testing, and expressed in MPa. The elongation at break (ε) was calculated taking into account the initial length of the film sample taken for testing, and expressed as a percentage. The values of elongation at break and tensile stress were calculated as the arithmetic average of five parallel measurements. The hemocompatibility of chitosan-glycerol succinyl systems was evaluated by determining the osmotic resistance of healthy human erythrocytes using a unified method in the modification of L.I. Idelson. It is shown that the introduction of glycerol as a plasticizer in the process of film formation leads to a significant improvement in their physical and mechanical characteristics. An increase in the glycerol content in the film up to 50 wt% is accompanied by a significant increase in tensile elongation. The value of the breaking stress in this case, naturally decreases. But, since the value of the breaking stress in any case remains at the level of the necessary values, the observed drop in strength indicators is not fundamental. The stabilizing effect of the succinyl of chitosan-glycerin systems on cell membranes under physiological conditions is proved, which suggests their high hemocompatibility.

It was investigated the effect of the method of obtaining polymer composites based on the blend of polymers over a wide range of their ratios on the rheological and physical-mechanical properties. The composites were prepared (using pressing or pressure die casting) on the basis of secondary polypropylene (PP) and the following polymers: 1) ultra high molecular polyethylene (UHMPE); 2) ethylene propylene diene monomer (EPDM); 3) secondary low pressure polyethylene (LPPE). Pressing was carried out on an automatic hydraulic press "AutoMH-NE" (Carver, the USA) at 210°C and endurance under pressure of 7000 kgfs within 3 min. Injection molding was performed using a Babyplast automatic molding machine of the horizontal type with an injection volume of up to 15 cm3. In both cases, the compositions also went through a stage of the preliminary mixture at the laboratory station (plastograf) of "PlastographEC" (Brabender, Germany) within 15 min at a load of 200 N. Estimation of rheological properties of the polymer composition melts was performed using a Haake Mars III rheometer. The deformation-strength properties were studied according to the State Standard GOST 11262-80 with a tensile testing machine "Shimadzu AGS-X". Using the data of relative rheometry, it is determined for all the systems studied (blends PP with UHMPE, EPDM, and LPPE) that variation of the maximum torque with composite composition is non-additive. This seems to be due to the occurring phase reversal. The present fact finds its support when performing rheological investigations using absolute rheometry. It is shown that variations in the phase structure of composites occurring in the phase reversal area lead to the corresponding changes in the deformation-strength properties of composites.

Досліджено ферментативну деструкцію лі- карських плівкових матеріалів на основі хітозану та анти- біотиків цефалоспоринового ряду. Встановлено, що наявність цефазоліну і цефатоксиму у плівкових зразках зменшує швидкість деструкції хітозану і приводить до потенційно довшого терміну служби захисного плівкового матеріалу на рановій поверхні. Enzymatic destruction of film materials on the basis of chitosan and antibiotics was analyzed. It was established that presence of drugs in a film sample caused a decrease in the rate of destruction of chitosan and led to a potentially longer service life of film material on the wound surface.

Enzymatic degradation of polymer-colloid dispersions of chitosan acetate and chitosan succinamide with silver iodide sols was studied. The enzymatic degradation rate both in solutions and in film samples decreases in the presence of charged particles of the lyophobic sol. This fact is due to the enzyme inhibition by silver ions and to changes in the conformational and supramolecular state of the polymers.

The aim of this work was the investigation of the formation of structures in solutions of individual polymers, as well as their blends with each other in buffer solvents with different values of pH. In this study we used a sample of chitosan (degree of deacetylation ~ 84 %, M = 130,000), which is a polycation when dissolved, and polyvinyl alcohol (r = 1.25 g/cm3, M = 5000). Buffer systems based on acetic acid and sodium acetate with pH = 3.8, 4.25, and 4.75 were used as solvents. Viscosimetry was used to determine the intrinsic viscosity, the degree of structuring, and the Huggins constant. The Kriegbaum method was used to determine the nature of the aggregates formed by the blend of the studied polymers. In the course of the research, it was shown that an increase in the pH of the acetate buffer used as a solvent was accompanied by a compression of the macromolecular coil (a decrease in intrinsic viscosity values), a deterioration in the quality of thesolvent (an increase in Huggins constant values), and an increase in the degree of polymer aggregation in a solution for chitosan polyelectrolyte. At the same time for a solution of polyvinyl alcohol the pH of the buffer practically did not affect the nature of the polymer-solvent interaction. It has been proved that polymer blends are characterized by an increase in aggregation processes and a decrease in the thermodynamic quality of the solvent in comparison with solutions of individual polymers. The size of the “combined” macromolecular coil, characterized by the intrinsic viscosity value for the polymer blend, which can be both above (buffer solvent with pH = 3.80) and below (buffer solvent with pH = 4.25 and 4.75) additivevalues, changed depending on the type of formed polymer-polymer aggregates (homo- or hetero-). It was established that the type of aggregates (homo- or hetero-) formed in solutions of polymer blends was determined not only by the thermodynamic quality of the used solvents, but also by the concentration of the polymers in the initial solutions

Целью данной работы является изучение реологических характеристик полимерной композиции на основе вторичного полипропилена и наполнителей растительного происхождения.В работе использовали образец вторичного полипропилена, соответствующий первичному полипропилену марки FF/3350, представляющий собой дробленый материал из некондиционных изделий, производимых методом литья под давлением в технологическом производстве ООО «ЗПИ Альтернатива» (Россия, Республика Башкортостан, г.Октябрьский). В качестве наполнителя были рассмотрены материалы, являющиеся отходами производств – лузга гречихи, полова (мякина) пшеницы, рисовая шелуха и древесная мука. Моделирование процесса переработки полимерных материалов осуществляли в расплаве на лабораторной станции (пластограф) «PlastographEC» (Brabender, Германия). Физико-механические свойства полимерных композитов при разрыве определяли на разрывной машине «ShimadzuAGS-X» (Shimadzu, Япония). Реологические измерения проводили на модульном динамическом реометре Haake MarsIII.В ходе исследований было показано, что для всех изученных наполнителей имеет место увеличение вязкости расплава полипропилена при добавлении их в композицию. Показано, что по мере увеличения содержания наполнителя в системе не только увеличиваются их вязкие свойства, о чем свидетельствуют значения комплексной вязкости, но и их упругие характеристики Установлено, что по мере наполнения полимера растительными компонентами, происходит закономерное увеличение модуля накоплений, что характерно для систем, проявляющих упругие свойства. Утверждается, что при использовании рисовой шелухи и древесной муки в качестве наполнителей формируются композиты, характеризующиеся высокими значениями модуля накоплений и соответственно повышенными значениями модуля Юнга. Было доказано, что оптимальным содержанием наполнителя является значение, соответсвующее 10 mass.h. ЛИТЕРАТУРА Айзинсон И.Л. 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The effect of organic cosolvents (ethanol and isopropanol) on the viscosity characteristics of acetic acid aqueous solutions of chitosan is studied. Sorption and deformation–strength properties, as well as resistance to the process of enzymatic degradation of materials obtained from solutions, are determined. It is shown that the introduction of cosolvents into the chitosan–1% acetic acid system is accompanied by a consistent decrease in the intrinsic viscosity of polymers. It is found that, in the presence of cosolvents, at concentrations below the crossover concentration, chitosan molecules exist as systems of interacting (aggregated) macromolecules rather than isolated macromolecular coils. A change in the conformation of chitosan and the type of macromolecular aggregates in acetic acid solutions in the presence of cosolvents leads to a number of consequences: polymer units become less accessible to an enzyme preparation, the rate of enzymatic degradation decreases, and mechanical characteristics of film materials change.

Polymer-colloid dispersions which are products of interaction of macromolecules with inorganic sol are of special interest among polymeric materials of biomedical function. The water-soluble sodium salt of chitosan suссinamide (SChT) having a complex of unique properties, among which is biocompatibility with body tissues, bacteriostaticity, ability to biodegradation, and so on, has been used as a basis for creation of film composite materials for biomedical purpose. Sol of silver iodide (AgI) known for its bactericidal properties has been used as colloidal dispersion. Microbiological studies have shown that films on the basis of polymer-colloidal dispersion SChT-AgI possess the expressed bactericidal action, while individual sol and individual SChT at the chosen concentration are characterized only by a bacteriostatic effect. It is revealed that polymer-colloidal dispersion SChT-AgI promotes an increase in resistance of components of blood to action of hemolytic agents. It is established that addition of AgI leads to an increase in tensile strength and decrease in elongation fracture. It is shown that the obtained films in all cases destruct much more slowly and to a lesser extent than an initial film of SChT when maintaining good water-absorbing ability.

Enzymatic hydrolysis of chitosan-based films supplemented with cephtasidim and cephtriaxone antibiotics on a substrate saturated with water, diluted acetic acid, or Ringer-Locke physiological saline was studied. Supplementation with antibiotics having the chemical structure of low molecular weight salts reduced the rate of enzymatic hydrolysis of chitosan regardless of the medium used. The decrease was related to the suppression of polyelectrolyte swelling of the polycation rather than enzyme inhibition. The addition of antibiotics to chitosan films can apparently be considered an approach to directed reduction of the film enzymatic hydrolysis rates, which may contribute to an increase in film lifetime on the wound surface.

Rheological studies of solutions of amphiphilic copolymers based on hydrophilic polysaccharides chitosan (CT) and chitosan succinamide (CTS) sodium salt with methyl acrylate (MA) synthesized by radical copolymerization have been conducted. It has been found that the hydrophobic interaction of poly(methyl acrylate) blocks in solutions of CT–MA and CTS–MA copolymers leads to an increase in the degree of structuring of macromolecules; this feature leads to the formation of an elastoviscous system without introducing of an additional crosslinking agent.

The rheological properties of aqueous solutions of a sodium salt of carboxymethyl cellulose are studied. The occurrence of a region of unstructured semidilute solutions in which the entanglement network is absent is found. The introduction of both opposite and like-charged micelles of the lyophobic sol into a semidilute polymer solution leads to its structuring due to the appearance of an additional network because of polymer adsorption on the surface of the sol. As a result of the network formation a decrease in the interval between the crossover and the formation concentration of the entanglement network and also an increase in the viscosity of the semidilute solution are observed.

The process of water vapor sorption by medical chitosan films and the release of nonelectrolyte drugs from these films are investigated. It is shown that the nonelectrolyte drugs are unable to modify the chitosan matrix and cannot provide a prolonged drug release. The modification of chitosan–drug films, for example, by isothermal annealing or transition from the salt form of chitosan to the base one, is required to decelerate the release of drugs from the films.

The enzymatic decomposition of film materials based on chitosan with inclusions of cephalosporin antibiotics on a substrate impregnated with Ringer–Locke’s solution was studied. The introduction of antibiotics led to a decrease in the rate of the enzymatic decomposition of chitosan, as in the case of chitosan lysis in the presence of aminoglycoside antibiotics. A possible reason for the decrease in the rate of the enzymatic decomposition of chitosan is suppression of polyelectrolyte swelling in the presence of low-molecular electrolytes including medicinal agents. The introduction of drugs in the chitosan-based film is a potential method for selectively decreasing the rate of enzymatic hydrolysis of chitosan for increasing the service life of the film material on a wound surface.

Запропоновано підхід до одержання пружно-в’язких систем на основі хітозану без зшиваючих агентів, суть якого полягає у формуванні додаткової сітки фізичних зв’язків внаслідок введення низькомолекулярного модифікатора – етанолу або гліцерину. Встановлено, що структуроутворення хітозану в розчині супроводжується формуванням додаткової сітки фізичних зв’язків, вузлами якої є агрегати молекул хітозану, сформовані у змішаному розчин- нику оцтова кислота-вода-гліцерин або оцтова кислота-вода- етанол. Це сприяє скорішому формуванню пружно-в’язкісних властивостей, що приводить до гелеутворення за нижчих концентрацій полімеру у порівнянні з розчином хітозану без додавання спирту. Одержані гелеподібні системи мають задовільну біосуміснсть, і тому можуть використовуватись як полімерні форми лікарських засобів. We propose an approach to the preparation of viscoelastic systems based on chitosan without crosslinking agents. It is the formation of an additional network of physical links by introducing a low molecular weight modifier – ethanol or glycerol. It turns out that gelation of chitosan in the solution is accompanied by the formation of additional meshes of physical links, nodes or aggregates of chitosan macromolecules formed in a mixed solvent of acetic acid-water-glycerol or acetic acid-waterethanol. It promotes an earlier formation of viscoelastic properties, which eventually leads to gelation at lower polymer concentrations than in the case of chitosan solutions without alcohol additives. The resulted gelled systems are characterized by good biocompatibility, and therefore can be used as polymeric forms of drugs.

The reactions of the polysaccharides pectin (Pc) and chitosan (CTS) with antibiotics of cephalosporin and aminoglycoside series were studied. The complexation between the drugs and polymers was found to occur via hydrogen bonding. Dilution of the chitosan polycation increased the probability of occurrence of the negative ions of the cephalosporin antibiotic near the chain and lowered the probability of occurrence of the positive ions of aminoglycoside antibiotics, which affected the amount of adducts. When the pectin polyanion was diluted, the opposite situation was observed.

The effect of water-soluble polymer—chitosan succinamide—on surface activity of such commonly used surfactants as anionic sodium dodecylsulfate and nonionic TWEEN-80 is investigated. It is shown that the combined use of sodium dodecylsulfate and TWEEN-80 with chitosan succinamide increases the surface activity of the investigated surfactants. It is found that the association of chitosan succinamide with sodium dodecylsulfate or TWEEN-80 begins at concentrations an order of magnitude lower than the critical micelle concentration of studied surfactants. The fact of reduction in the dynamic viscosity of the solution of chitosan succinamide in the presence of both ionic and nonionic surfactants, apparently owing to the formation of polymer-colloid complexes, is revealed. The obtained systems have a stabilizing effect on the membrane of red blood cells in stringent hypotonic conditions, which may indicate a decrease in the adverse effect of surfactants on the skin.

The effect of preparation conditions for positively and negatively charged silver iodide sols on the particle size and number concentration has been determined. It has been found that the preparation of a mixture of precursors with a concentration of 0.01 mol/L at a KI to AgNO3 volume ratio of 10: 7 or 7: 10 leads to the formation of a large number of small particles (on the order of 50–60 nm) corresponding to the range of true colloidal systems with a maximum interfacial area. The presence of a polymer stabilizer–chitosan–leads to a significant improvement of the stability of the sol particles, which makes it possible to use the resulting polymer-colloidal dispersions containing nanoparticles of silver iodide sols to design hybrid materials for biomedical applications.

The enzymatic destruction of chitosan in an acetic acid solution in the presence of sodium chloride and sulfate was considered. It was shown that the addition of these low-molecular electrolytes is accompanied by a tightening of the macromolecular coil, as indicated by a decrease in the α constant in the Mark–Kuhn–Houwink equation and the intrinsic viscosity of chitosan. As a consequence, the chitosan units become less accessible for interaction with the enzyme, and the kinetic parameters of the process (Michaelis constant K M and the maximum rate of enzymatic destruction V max) change accordingly. This suggests that the resistance of this polymer to the enzyme action can be enhanced by introducing low-molecular electrolyte salts in the solution or film coating to suppress the polyelectrolyte swelling of chitosan.

Film systems based on chitosan with different molecular weights (334 000 and 113000 Da) and amikacin, an aminoglycoside series antibiotic, are studied. The Ritger–Peppas, Hixson–Crowell, and Hopfenberg equations for describing the kinetics of drug release are tested. It is demonstrated that the release of amikacin from chitosan acetate films under conditions of concurrent diffusion and dissolution (hydrolysis) of the polymer matrix are more closely described by the Hopfenberg equation. It has been established that the isothermal annealing of the film causes a decrease in the kinetic constants characterizing the rate of drug release from the polymer matrix.

Some ways of estimating the values of the intrinsic viscosity of chitosan were analyzed. It was shown that the method of Irzhak and Baranov for estimating the current value of the intrinsic viscosity allows to adequately estimates the conformational state of the macromolecular coil and its degree of swelling. Проаналізовані деякі способи оцінки значення характеристичної в'язкості хітозану. Показано, що метод Іржака і Баранова для оцінки поточного значення характеристичної в'язкості дає можливість адекватно оцінювати конформаційний стан клубка макромолекул і його ступінь набухання.

The resistance of film coatings based on chitosan and aminoglycoside antibiotics, such as amikacin sulfate, to hyaluronidase enzyme preparation is considered. Despite the use of a solid film sample in enzymatic hydrolysis, the regularities of the process are similar to those observed in the hydrolysis of chitosan in solution at low concentrations of substrate. The addition of the drug leads to a reduction of the rate of enzymatic hydrolysis of chitosan and provides the potentially longer service life of protective film materials on the wound surface.

The kinetics of controlled release of medicinal substances from chitosan films has been investigated. Correlation between values of diffusion coefficients and the sedate indicator characterizing diffusion of medicinal substance from a film and shares of medicinal substance connected with a polymeric chain has been established. With the increase in amount of the entered medicinal substance the rate of release of medicines decreases. Досліджено кінетику контрольованого вивільнення лікарських речовин з хітозанових плівок. Встановлено взаємозв‘язок між значеннями коефіцієнту дифузії, показником, що характеризує режим дифузії, та часткою лікарської речовини, зв‘язаної з полімерною матрицею. Показано, що зі збільшенням кількості лікарської речовини швидкість їх вивільнення зменшується.

Approach of obtaining molded composites on the basis of the mixtures of powders of nano-dispersed polyethylene, cellulose and ultra-dispersed carbonic materials has been developed. Тhese materials possess the assigned sorption properties and the physic-mechanical characteristics. Тhey are suitable for the usage in the process of cleaning and separation of gas mixtures.

It is found that there is substantial difference in the intrinsic viscosities of solutions of chitosan before and after its reprecipitation from acetic acid solutions. It is shown that this fact is not related to destructive processes, but is caused by the tendency toward a change in the supramolecular structure of chitosan during its dissolution in a thermodynamically good solvent.

Rheological properties of chitosan solutions have been studied. The region of nonstructured semidilute solutions free of fluctuation networks has been revealed. The addition of oppositely charged micelles of a lyophobic sol to a semidilute polymer solution results in structurization of the solution owing to the appearance of an additional network formed by the polyelectrolyte complex between the polymer and the colloid particles. As a result, the interval between the crossover concentration and the concentration of the fluctuation-network formation decreases, whereas the viscosity of the semidilute solution grows.

The effect of antibiotics of the aminoglycoside and cephalosporin series on the properties of chitosan films formed from acetic acid solutions is studied. It is shown that the introduction of the indicated substances substantially affects the conformational state of chitosan acetate and its supramolecular structure. The modification of chitosan by drug substances, accompanied by loss in solubility of chitosan films in water, leads to a decrease in the rate of desorption of antibiotics from the polymer matrix.

Self-organization of a water-soluble chitosan derivative, chitosan succinamide sodium salt, in the presence of colloidal particles of silver iodide sol was studied. The polymer–colloid disperse system formed is essentially a polymer–inorganic nanocomposite in which chitosan succinamide macromolecules act as a stabilizer of inorganic nanoparticles. The reaction of the system components leads to the formation of a network of intermolecular contacts whose nodes are colloidal particles of silver iodide sol, on which the polymer chains are specifically adsorbed. The chitosan succinamide–silver iodide sol ultradisperse systems exert a stabilizing effect on erythrocyte membranes.

To examine the influence exerted on the degree of hydrogenation and hydrogenolysis by the content of olefin (diolefin) and polycyclic aromatic hydrocarbons at different fractional compositions of distillate mixtures, joint hydropurification of vacuum gasoil with benzine and light and heavy coking gasoils was performed. The study was carried out in a laboratory installation under a hydrogen pressure of 5.0 MPa, temperature of 375°C, volumetric flow rate of raw materials of 1 h−1, and H2/raw material ratio of 1000/1. The effect of the composition of raw materials and process conditions on the chemical composition and quality parameters of the resulting products was demonstrated. It was shown that a pronounced competition between olefin and polycyclic aromatic hydrocarbons in hydrogenation reactions is observed for mixtures of heavy vacuum gasoil and light coking gasoil, in contrast to mixtures of straight-run diesel fraction and light coking gasoil.

The kinetics of the enzymatic hydrolysis of chitosan film samples under the action of the enzyme hyaluronidase was studied. It was found that, although a monolithic film sample was subjected to hydrolysis, the enzymolysis of chitosan in this case obeyed the same laws as the enzymatic hydrolysis of chitosan in solution at small substrate concentrations.

The transport properties of films based on chitosan and a drug have been studied, and sorption and diffusion characteristics of the films have been examined. The calculated diffusion coefficients and the abnormal kinetic curves of amikacin release have been discussed. An analysis of the obtained data showed that the process of drug transport from chitosan films deviated from the classical Fick’s laws due to structural changes in the polymer matrix induced by its chemical modification because of interaction with the drug.