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Determination of Paracetamol content in selected drugs using ATR-FTIR spectrometry
Waczulíková, Kristína ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis deals with determination of paracetamol content in selected drugs by ATR-FTIR spectrometry and aims to design and optimize determination of paracetamol in dosage forms by a direct measurement of the sample, called ‘dry way’. Tablets of three drugs containing paracetamol have been studied. Wavelength ranges were determined from the measured FTIR spectra as regions where the absorptions of fillers (microcrystal cellulose, starch and magnesium stearate) were minimal. Absorption bands of paracetamol were selected at the wavenumbers of 1 503 cm-1 and 1 224 cm-1 in order to construct a calibration curve. The contents of paracetamol in the drug tablets were calculated using calibration curves obtained by the method of simple regression analysis. The lowest deviation from the amount of 500 mg paracetamol per tablet as reported by the manufacturer was from the calibration curve for paracetamol with microcrystalline cellulose. The determined amounts of paracetamol per tablet in the selected drugs lied within range 493.5–505.5 mg. These results point to the conclusion that the ATR-FTIR spectrometry method can be used for the quantitative determination of paracetamol in drugs using direct measurement, as deviations from the reference value of 500 mg did not exceed 1.5 % for cellulose and 3.85 % for magnesium stearate and therefore are within acceptable limits for the exploratory study.
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Program-controlled freeze drying for the preparation of the drug-delivery system based on polysaccharide and hydrophobic molecules
Dufková, Michaela ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
The lyophilization process favors the hydrophobic effect between the individual dextran chains. This hydrophobic effect allows hydrophobic drugs to settle and remain within the biopolymer. Due to hydrophobic effect, dextran can serve as a carrier for the distribution of hydrophobic drugs. The goal of this thesis was to prepare a carrier system based on native dextran using program-controlled freeze-drying. Hydrophobic drugs were modeled using the fluorescent probes pyrene and prodane. The effectiveness of promoting the hydrophobic effect was studied using infrared spectrometry, fluorescence spectrometry and scanning electron microscopy. Using ATR-FTIR spectrometry, a shift of the absorption band of thevalence vibration of the C–O bond in OH groups in alcohol was observed. Using fluorescence spectrometry, the emission polarity index was calculated for pyrene from the 1st and 3rd maximum fluorescence intensity, and for prodan, a shift of the maximum fluorescence intensity to lower wavelengths was observed. SEM images showed that during the lyophilization process, the dextran structure formed a dense network of fibers, indicating the presence of many sites with a higher content of hydrophobic domains. Positive results were obtained with these methods, which proved the positive effect of lyophilization on the formation of a hydrophobic effect between individual polysaccharide chains. The results may contribute to the development of carrier systems for hydrophobic drugs.
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Determination of Paracetamol content in selected drugs using ATR-FTIR spectrometry
Waczulíková, Kristína ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis deals with determination of paracetamol content in selected drugs by ATR-FTIR spectrometry and aims to design and optimize determination of paracetamol in dosage forms by a direct measurement of the sample, called ‘dry way’. Tablets of three drugs containing paracetamol have been studied. Wavelength ranges were determined from the measured FTIR spectra as regions where the absorptions of fillers (microcrystal cellulose, starch and magnesium stearate) were minimal. Absorption bands of paracetamol were selected at the wavenumbers of 1 503 cm-1 and 1 224 cm-1 in order to construct a calibration curve. The contents of paracetamol in the drug tablets were calculated using calibration curves obtained by the method of simple regression analysis. The lowest deviation from the amount of 500 mg paracetamol per tablet as reported by the manufacturer was from the calibration curve for paracetamol with microcrystalline cellulose. The determined amounts of paracetamol per tablet in the selected drugs lied within range 493.5–505.5 mg. These results point to the conclusion that the ATR-FTIR spectrometry method can be used for the quantitative determination of paracetamol in drugs using direct measurement, as deviations from the reference value of 500 mg did not exceed 1.5 % for cellulose and 3.85 % for magnesium stearate and therefore are within acceptable limits for the exploratory study.
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