Despite the good therapeutic potential many newly discovered active pharmaceutical ingredients have poor water solubility. The development of drugs with such active ingredients is often stopped very quickly. If we manage to improve their solubility and/or dissolution rate, they become interesting for further development. The aim of this master thesis was to increase the dissolution rate and solubility of carvedilol by its incorporation into hydrophilic polymer nanofibers. Polyethylene oxide and poloxamer 407 were used as key nanofiber matrix formers. Selected lipids (mango, cocoa or macadamia butter) and carvedilol were later also incorporated in nanofibers. The produced nanofibers had uniform thickness, random distribution and smooth surface, without pores in the structure. The incorporation of lipid, the type of lipid and the percentage of the active ingredient in nanofibers did not affect the rate of carvedilol release from nanofibers, as the drug was completely released from all nanofiber formulations in 10 minutes. The solubility of pure carvedilol, it's physical mixture and polymer nanofibers were also investigated. The results revealed that equilibrium solubilities of pure drug, drug in physical mixture and drug in nanofibers are similar. Dissolution of nanofibers revealed a supersaturated solution, which was not physically stable, as carvedilol precipitation was observed in two hours. One of the reasons for the supersaturation might be the presence of amorphous carvedilol in nanofibers. During electrospinning the active ingredient can incorporate into nanofibers in amorphous form, which can be verified by the differential scanning calorimetry. The absence of a sharp endothermic peak at 120 ° C may indicate the absence of the crystalline form of carvedilol in nanofibers, but this cannot be confirmed only based on obtained results, as carvedilol may have dissolved in the melt of polymers during the analysis. Infrared spectroscopy with Fourier transformation was also performed to investigate the presence of interactions between components in nanofibers. There was no visible peak characteristic for the carvedilol in the spectrum of nanofibers at 3300 cm-1. Other peaks characteristic for carvedilol were less pronounced and there were no noticeable shifts of peaks in the spectra compared to the peak positions in the spectra of individual substances. Based on the obtained results we cannot conclude with certainity that carvedilol was incorporated in nanofibers in amorphous form and that there were interactions between the individual components in the nanofiber formulations. However, the results of our study showed that the incorporation of carvedilol into nanofibers increase its solubility and dissolution rate.
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