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EN
The aim of the study was to evaluate the effect of methylcellulose and carboxymethylcellulose on the rheological properties of hydrogels applied to skin on chitosan in the presence of the additives propylene glycol and glycerol. Rheological studies showed that the tested gels are non-newtonian systems, and have thixotropic properties. Substrates made of methylcellulose and chitosan are characterised by higher shear values than those obtained with carboxymethylcellulose. The addition of polymers had a positive influence on the dispersion of hydrogels, and the addition of excipients increased firmness, consistency and cohesiveness of the gels. Larger increases were observed with the addition of 10% of glycol propylene and glycerol contents for methylcellulose and of 20% of carboxymethylcellulose.
EN
The aim of the study was to evaluate the effect of Carbopol 934 P and PVP K 90 on the rheological properties of chitosan gels. Hydrogels were prepared with hydrocortisone containing chitosan, Carbopl 934P, PVP, propylene glycol-1,2 or polyethyleneglycol 400 and glycerol. Addition of polymers had positive influence on the dispersion of hydrogels. The studied gels have thixotropic properties, their viscosity increases with the increase of the concentration of polymers. Increase of the content of polyvinylpyrrolidone K 90 and Carbopol 934 P increases the consistence, gels are more firm and cohesive. Gels with 5 % chitosane, 15% polyvinylpyrrolidone K 90 and Carbopol 934 P in the presence of additives have prolonged half release period of hydrocortisone.
EN
In clinical practice, in the treatment of obesity, a plurality of natural high-molecular compounds are used, the activity of which supports weight loss. During the use of dietary supplements containing chitosan, illness sometimes develops and other therapeutic agents are applied as antibiotics The aim of our study was to determine the binding capacity of the antibiotic erythromycin depending on variable physicochemical factors, in the model of the gastrointestinal tract, by chitosans found in slimming dietary supplements Erythromycin adsorption phenomenon was studied by static and dynamic pharmaceutical model (according to the modified method of the Polish Pharmacopoeia) simulating in vitro conditions. The amount of bound drug was used to calculate the average percentage of the adsorbed dose. The results obtained show that erythromycin is adsorbed by chitosans at various pH ranges, and the binding capacity of the environment depends on the pH, viscosity and concentration of the antibiotic, as well as the chitosan and type and additional substances present in the gastrointestinal tract. The average level of the adsorption of erythromycin in the chitosan-nutrients system depends on the pH of the medium. The highest amount of adsorption was noted above pH 7 (chitosan precipitated polymer forming the emulsion-gel system).
EN
The aim of this work was to study the properties of methylcellulose hydrogels with supplements containing chitosan and 1% hydrocortisone. Depending on the composition of the substrate, gels are characterised by a variety of pharmaceutical availabilities. Increasing the concentration of chitosan has an influence on increasing the viscosity, hardness, and cohesiveness of the tested gels.
EN
The aim of the study was to investigate the effect of chitosan on the dissolution of ketoprofen incorporated into this polymer carrier. The study investigated ketoprofen in physical mixtures at the drug to polymer ratios of 1:9, 3:7, and 5:5. The solubility investigation was performed by means of a dynamic method in a dissolution apparatus; the mean amount of dissolved ketoprofen and the drug to polymer quantitative ratio in which the solid dispersion possessed the most beneficial properties improving the drug solubility were calculated. The study revealed a multifold increase (33 times) in ketoprofen solubility in the presence of chitosan, which increased with duration of the study and with increasing percentage of the polymer in formulations. The dissolution rates of ketoprofen in the presence of chitosan at the weight ratio 1:9 increased with the decrease of the molecular weight of the chitosan. The results obtained may help to develop new technologies for ketoprofen preparations with chitosan, with better solubility characteristics, and thus increased bioavailability of the drug.
EN
The aim of the study was to investigate the effect of chitosan on the dissolution of fenofibrate incorporated into this polymer carrier. The study investigated fenofibrate in physical mixtures at the drug to polymer ratio of 1:9, 3:7, and 5:5. The solubility investigation was performed by means of a dynamic method in a dissolution apparatus; mean amount of dissolved fenofibrate and the drug to polymer quantitative ratio in which the solid dispersion possessed the most beneficial properties improving the drug solubility were calculated. The study revealed a multi-fold increase (from 13 to 70 times) in fenofibrate solubility in the presence of chitosan, which increased with duration of the study and with increasing percentage of the polymer in formulations. The dissolution rates of fenofibrate in the presence of chitosan at the weight ratio 1:9 increased with the increment of the molecular weight of the chitosan. The obtained results may help develop new technologies for fenofibrate preparations with chitosan, with better solubility characteristics, and thus increased bioavailability of the drug.
EN
Combinations of polymers and biopolymers of biologically active compounds in the last period have been the subject of intensive research. The active substance linked to a polymer often has a modified function and sometimes no action. On the other hand, the use of unsuitable polymers may result in a type of mismatch of drug-polymer. The aim of the study was to examine whether the active substance ketoconazole causes incompatibility with dietary supplements containing chitosan. Antifungal drug adsorption phenomenon was investigated by the static method in the concentration range of the single dose using a pharmaceutical model of the gastrointestinal tract. The test results show that the antifungal agent is adsorbed onto the chitosan in the pH ranges used, and the binding ability of the chitosan depends on the variety, or indirectly from the reaction environment. It was observed that the average sorption, depending on the variety of chitosan, was located in the limit from 94% to 100%. The increase of the size of the adsorption of anti-inflammatory drugs on the polymer with increasing pH from 7.6 to 8.0 can be explained by the swelling properties of chitosan, which grow with increasing pH of the environment in the direction of alkaline pH. Thus, the specific surface area and polymer sorption capacity is increased. Based on the above considerations, it can be concluded that, between the test drug and the polymer, there is antagonistic interaction involving the adsorption of the drug of this group on a polymer which is chitosan.
EN
The effect of chitosan concentration on the properties of dermatological preparations prepared with 2% methylcellulose and 10% polyvinylpyrrolidone was studied. As the levels of chitosan, propylene glycol-1,2 and glycerol increased, the hardness, consistency and cohesiveness of the hydrophilic gels increased, while the dissipation capacity decreased. Gels based on methylcellulose and chitosan, compared to formulations containing polyvinylpyrrolidone, have a higher rate of loss of volatile compounds, higher pH values for 1,2-propylene glycol formulation and higher texture parameters. The tested hydrogels have good rheological properties, allowing extrusion from the tube and spreading on the skin.
EN
BCS class II includes drugs with low solubility and high permeability. Ketoprofen is an example of this class of drugs. The aim of the study was to investigate the effect of chitosan with average molecular weights in various formulations on the dissolution of ketoprofen incorporated into this polymer carrier. The study investigated ketoprofen in solid dispersions using a method of the solvent evaporations at the drug to polymer ratios of 1:9. 3:7, and 5:5. The highest dissolution of fenofibrate, amounting to 98.8%, was observed after 60 minutes from solid dispersions with a drug-polymer weight ratio 1:9 in the presence of chitosan B and was 32-times higher in relation to the amount of added polymer in comparison to the solubility of pure drug. DSC and IR investigations showed that ketoprofen remained in its crystalline state in solid dispersion. There was no change in the chemical structure of the drug after the incorporation of the drug onto the polymer. Chitosan has been proposed as a useful excipient for enhancing the bioavailability of poorly water-soluble compounds.
EN
The aim of the study was to evaluate the effect of changing the concentrations of chitosan on the rheological properties of the obtained formulation. Hydrogels were prepared with 1% hydrocortisone containing 4% sodium carboxymethylcellulose with the addition of chitosan, propylene glycol-1,2 or polyethylene glycol 400 and glycerol or paraffin. The concentration of chitosan and excipients affects the rheological properties of gels and the pharmaceutical availability of hydrocortisone. Increasing the concentration of chitosan have influence on increasing the viscosity, hardness, and cohesiveness of the tested gels.
EN
In clinical practice for the treatment of obesity, several natural macromolecular compounds are used, whose operation is based on supporting weight loss. During the use of dietary supplements containing chitosan, disease sometimes occurs and treatment for this often comprises different therapeutic agents and antibiotics. The aim of our study was to determine the binding capacity of simvastatin to chitosan, which is found in dietary supplements promoting weight loss, depending on variable physicochemical factors in the gastrointestinal tract model. The phenomenon of adsorption of simvastatin was investigated by a static and dynamic pharmaceutical model (according to the Modified method of Polish Pharmacopoeia IX) simulating the conditions in vitro. The amount of bound drug is used to calculate the average percentage of the adsorbed dose. The obtained results showed that simvastatin is adsorbed by chitosan in the used pH ranges, and the binding capacity is dependent on the environmental pH, viscosity, the concentration of the drug, the type of chitosan and additional substances present in the gastrointestinal tract. The average adsorption of simvastatin in the system of chitosan-nutrients, depending on the pH of the medium, was in the range of 27 to 95%. The highest amount of adsorption was noted above pH 7 (chitosan precipitated polymer forming the emulsion-gel system), when the bioavailability of dietary supplement using chitosan was almost zero.
EN
The aim of the present study was to increase the solubility of ibuprofen. Among the methods to increase the solubility selected solid dispersions of the drug with the polymer. Chitosan was used as the polymer. Solid dispersion obtained. Ibuprofen was incorporated into the chitosan type 652 with molar masse chitosan Mη = 429 kDa. Solid dispersions were prepared by using different ratios of ibuprofen and chitosan (1:9. 3:7 and 5:5). Formulations were tested dissolution rate of the ibuprofen. The highest dissolution of ibuprofen, amounting to 12.59%, was observed after 60 minutes from solid dispersion prepared by the evaporation method and 12.18% from physical mixtures with drug-polymer weight ratio 1:9 in the presence chitosan. The solubility of the drug improved more than 60-fold. XRPD analysis indicates the presence of the ibuprofen in amorphous form in the solid dispersion obtained by the modified solvent evaporation.
EN
During the pharmacological therapy of specific diseases, drugs are used which, with other preparations or foods, can create connections, in many cases changing or even blocking their action. On the other hand, the use of unsuitable polymers as excipients may result in drug-polymer incompatibilities. Interactions consisting mainly of the occurrence of the adsorption phenomenon and on the formation of complex bonds that reduce the effect of the drugs are of particular importance. The aim of the study was to investigate whether the active substance atorvastatin is incompatible with dietary supplements containing chitosan. The phenomenon of the adsorption of the drug was examined using a static model of a pharmaceutical gastrointestinal tract, in the concentration range generally ingested in a single dose. Measurement results of the amount of bound drug were used to determine the average percentage of adsorbed drug dose. The results of the study prove that the anticholinesterase drug is adsorbed on chitosan in the pH ranges used, and that the binding capacity depends on the chitosan variety, which indirectly affects the reaction of the environment. It was observed that the average size of sorption depending on the chitosan variety ranged from 38% to 86%. The fact that the lowest value of adsorption was at pH 6.4 can be explained by the chemical properties of chitosan, which shows a charge only at pH >6.7. Under such conditions, the phenomenon of electrostatic adsorption may occur in relation to the healing substances of weak acids. At a pH above 7.6, corresponding to the intestinal fluid-filled intestine, the mean sorption for the highest dose of chitosan was from 38–86%. The increase in the adsorbed amount of anticholinesterase drugs on the polymer along with the increase in pH from 7.6 to 8.0 can be explained by the chitosan swelling properties, which increase with an increase in the pH. As a result, the specific surface area of the polymer and its sorption capacity increase. Based on the above considerations, it can be concluded that there is an antagonistic interaction between the drug and the polymer studied, which involves the adsorption of a drug from this group on the polymer (chitosan) and a decrease in its bioavailability
EN
The present work involves the development of a dental gel composition obtained on the basis of clotrimazole incorporated into chitosan in order to improve drug solubility. Solid dispersions were prepared by using two methods: grinding and kneading. The solid dispersion varied the ratio of chitosan to drug to increase the volume of the drug; the ratios were 5:5, 3:7, 2:8, 1:9. The mixtures were subjected to the dissolution rate of clotrimazole. The presence of chitosan improved the drug solubility; a better solubility from the solid dispersion prepared by the grinding method was obtained from the ratio of drug to polymer of 1+9. The rate of dissolution of clotrimazole was improved 17 times compared to the pure drug. Fourier transform infrared spectroscopy (both infrared and X-ray diffraction) revealed no new chemical structure of the tested connections and concluded that there was no interaction between the drug and the polymer in the test diffractions. Solid dispersions with the best parameters were used to prepare hydrogels, and the pharmaceutical availability of clotrimazole was analysed. The best properties were characterized by a hydrogel that was composed of the ratio of the amount of drug to polymer 5:5. The study demonstrated the availability of a pharmaceutical drug release at a therapeutic concentration in the first hour of the study. The use of the appropriate balance between clotrimazole and chitosan and the development of the hydrogel composition may affect the improvement of the drug solubility and may create the possibility of obtaining sustained or controlled release of the drug substance.
EN
The aim of the present study was to increase the solubility of clotrimazole. Among the methods to increase the solubility selected solid dispersions of the drug with the polymer. Chitosan was used as the polymer. Clotrimazole was incorporated into the chitosan type 652 with molar masse chitosan Mη = 429 kDa. Solid dispersions were prepared by using different ratios of clotrimazole and chitosan (1:9, 3:7, 5:5, 7:3, 9:1). Formulations were tested dissolution rate of the drug. The highest dissolution of clotrimazole, amounting to 47.95%, was observed after 60 minutes from solid dispersion prepared by grinding method and 42.84% from physical mixtures with drug-polymer weight ratio 1:9 in the presence chitosan. The solubility of the drug improved more than 37-fold. XRPD analysis indicates the presence of the clotrimazole in crystalline form in the solid dispersion obtained by kneading method.
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