Egeli Yılmaz, DeryaTırıs, GizemKepekçi Tekkeli, Şerife Evrim2026-06-062026-06-062026Egeli Yılmaz, D., Tırıs, G., & Kepekçi Tekkeli, Ş. E. (2026). A novel HPLC technique for the determination of casticin in pharmaceutical preparations and human plasma. Journal of Research in Pharmacy, 30(3), pp. 826-834. https://doi.org/10.12991/jrespharm.17087652630-6344https://doi.org/10.12991/jrespharm.1708765https://hdl.handle.net/20.500.13055/1508This study introduces a combined HPLC and UV detection technique for the quantification of casticin in capsule and human plasma samples. The chromatographic separation was carried out utilizing a C18 column (150 mm × 4.6 mm × 5 μm) at a temperature of 25 ºC. Isocratic elution with a mobile phase comprising 60:40 v/v (methanol-0.05% formic acid) was employed. Flow rate was adjusted 1 mL/min. The analyte was determined at a wavelength of 258 nm, with a retention time of 14.7±0.01 min. The developed method underwent validation according to ICH criteria, covering specificity, linearity, precision, accuracy, detection and quantitation limits, as well as robustness. The linear range was determined to be 10-60 ng/mL for both capsule and spiked plasma specimens. The suggested technique was performed to the analysis of casticin in spiked human plasma and pharmaceutical preparations, yielding a recovery of 106.04% and demonstrating precision through intra-day and inter-day experiments with the highest relative standard deviation (RSD %) value of 4.94. Consequently, the technique was performed to the quantifying of human plasma specimens from in a patient taking medication containing casticin.eninfo:eu-repo/semantics/openAccessCasticinHigh Performance Liquid ChromatographyValidationHuman PlasmaCapsuleArticle10.12991/jrespharm.1708765303826834Q42-s2.0-105039456606Q3