The aim of this paper was to formulate the composition of a bioadhesive film obtained based on acyclovir incorporated into natural bioadhesive polymers (chitosan and guar gum) in different quantitative ratios. To this end, the author developed a technology for preparing films containing various quantitative ratios of chitosan to guar gum: 1:0.25; 1:0.50; 1:0.75; 1:1; and 1.2:0.50. The formulations were used to prepare mucoadhesive films containing 2% acyclovir. The dressings were tested with respect to their physicochemical properties and subjected to dissolution testing. A comparative analysis of Fourier-transform infrared (FT-IR) spectra of pure polymers, acyclovir, and films containing polymers in different quantitative ratios was conducted. The quantitative ratio of chitosan to guar gum significantly impacted the mechanical properties of films: texture, elasticity, tensile strength, swelling, and blur time of the testes carriers. The 1:1 formulation showed the highest mechanical strength and flexibility. The dressing containing 1.2% chitosan and 0.5% guar gum had the longest blur time. An increase in the chitosan content in the formulation significantly affected the drug dissolution parameters, which makes it possible to achieve the desired effect of extended-release time. The FT-IR spectra excluded the formation of drug-polymer interactions. Changes in the quantitative ratios of chitosan and guar game in the carrier’s composition may impact the mechanical properties of the drug formulation and changes in the parameters of active substance release.
Drugs used in chemotherapy give undesirable side effects, e.g., cardiotoxicity, leucopenia, hair loss and others. Covalent binding of a drug with a carrier may change its biodistribution, elimination and/or rate of transformation in the organism. The aim of this work was to synthesize conjugates of anticancer drug - raltitrexed (RTX) with lysozyme, bovine serum albumin (BSA), and dextran T40 and to investigate their cytotoxicity and influence on the cell cycle in comparison with the free drug. Before conjugation RTX was transformed into anhydride by treatment with dicyclohexylcarbodiimide in dimethylformamide. Activated RTX was added into aqueous solution of carriers at different pH (from 8.5 to 10.5) for 3 to 15 min. The reaction was stopped by reducing the pH to 7.0. Maximum yield of the reaction was obtained at pH 10 for BSA as well as for dextran. The highest level of substitution was obtained after 5 min of the reaction. In in vitro experiments on three cell lines: SW707, LoVo and A549, all conjugates tested had up to a few hundred times higher IC50 than the free drug. Interestingly, it was noticed that the conjugates based on dextran and albumin were more cytotoxic than the free drug in the highest concentrations tested (1000 and 10000 ng/ml). The influence of RTX and the conjugates on SW707 cell cycle was studied. RTX blocked the cell cycle mostly in the G0-G1 and S phase and increased the percentage of apoptotic cells. Cells in the G2-M phase were not observed. The conjugates blocked the cell cycle in the S phase and decreased the percentage of cells in the G0-G1 phase.
Nanotechnology is a field that is gaining more and more importance in the modern world. It uses a particle size of between a few dozen to a few hundred nanometers, or 10-9 meters. It is noted that the use of nanospheres (balls with a diameter of from several to several hundred nm) as carriers of drugs gives an opportunity for their controlled and sustained release. (1,2) Nanospheres as a potential drug carrier for sustained release may enhance the effectiveness of antibiotics. In order to examine the effects of antibiotics with nanospheres an attempt was made to deposit on them three drugs differing in chemical structure. These were chloramphenicol, gentamicin and ceftazidime. The aim of this study was to determine the degree of adsorption of the drug on the surface of nanospheres and to examine the process of desorption from the surface of silica nanoparticles. The results of the study indicate that in the case of chloramphenicol it is essentially a process of chemisorption, and for gentamicin and ceftazidime both physical and chemical adsorption, without there being any clearly defined relationship between this two processes. The purpose of the nanospheres as drug carriers is to obtain controlled and prolonged exposure to the drug. The amount of adsorbed substance depends primarily on its structure. Ceftazidime, as the compound with the highest number of double bonds, and a large number of groups to form hydrogen bonds (carbonyl groups, amino groups), adsorbed to the greatest extent.
This study evaluated hydrogels containing Celugel, 3% hop cone extract obtained from Humulus lupulus L. using supercritical carbon dioxide extraction substrate, and 1% and 2% chitosan for dermatological application to treat inflammatory skin conditions. The presence of chitosan significantly affected the rheological properties of the formulations, including their dynamic viscosity, hardness, consistency, cohesiveness, and blurring time. The formulations containing 2% chitosan showed the best application possibilities. The formulations were evaluated for dissolution of cohumulone, which is an analogue of humulone contained in hop cone extract. The concentration of chitosan in the formulations had a significant effect on the dissolution testing parameters of the active ingredient: as the chitosan concentration increased, the desired effect of prolonged release time of the active ingredient was achieved while maintaining the membrane-forming properties of Celugel.
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