Sample pretreatment and HPLC determination of antiplatelet drug ticagrelor in blood plasma from patients with acute coronary syndromes.

A simple HPLC method was developed for the determination of antiplatelet drug ticagrelor (TCG) in blood. Sample preparation and extraction conditions were investigated and optimized. The preparation of blood plasma was investigated by protein precipitation using perchloric acid, methanol, acetonitrile (ACN), and trifluoroacetic acid. Protein precipitation using ACN was found to be the most suitable. Chromatographic separation of TCG was performed on a C18 column with a mobile phase consisting of ACN and 15 mM ammonium acetate buffered at pH 8.0. The method was applied to determine TCG in blood plasma of patients who had a heart attack. Blood samples were collected 1.5 h after the administration of the initial loading dose of the antiplatelet drug. The average concentration of TCG was found to be 0.97 ± 0.53 µg/ml. The developed method proved to be very selective, without interferences from other endogenous substances and the influences of possible coadministered drugs. The limits of detection and quantification estimated by the signal-to-noise ratio in real samples were 0.24 and 0.4 µg/ml, respectively. The developed method is simple and can be easily applied in clinics and emergency cardiac situations after the initial loading dose of TCG in the first few hours of a heart attack.

Caffeine in Hair Care and Anticellulite Cosmetics: Sample Preparation, Solid-Phase Extraction, and HPLC Determination.

Caffeine is extensively used in cellulite and hair growth cosmetic products. Regulations in the field of cosmetics require manufacturers to list caffeine in the ingredient list on product labels, but its exact content in these products is not declared. On the other hand, daily exposure to caffeine from all sources may approach health reference values. For that reason, it is important to know the exact caffeine content in products for skin and hair care. Cosmetics are often viscous or semisolid products of very complex chemical composition. To analyze caffeine in these complex sample matrices by liquid chromatographic methods, an extraction step is often necessary. This article presents the applicability of the solid-phase extraction (SPE) procedure for the caffeine extraction and high-performance liquid chromatography (HPLC) determination in anticellulite gels, shampoos, and hair balsam. The samples of gels were centrifuged after ammonia addition to precipitate carbomer. In cellulite reduction, gel caffeine content was found to be in the range of 0.7-1.7%, whereas in the hair-care products, it was about 1.0%.