Jan Meler

THE INFLUENCE OF A DENTAL FORMULATION PREPARED WITH CHITOSAN ON THE PHARMACEUTICAL AVAILABILITY OF CLOTRIMAZOLE

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. .

THE ADSORPTION OF SIMVASTATIN ON CHITOSANS IN AN IN VITRO PHARMACEUTICAL MODEL

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.

THE INFLUENCE OF SUBSTRATE COMPOSITION ON THE PHYSICOCHEMICAL PROPERTIES OF HYDROGELS WITH CHITOSAN

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.

PHYSICOCHEMICAL CHARACTERIZATION AND DISSOLUTION STUDIES OF SOLID DISPERSIONS OF CLOTRIMAZOLE WITH CHITOSAN

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.