RESUMEN
A rapid and accurate spectrofluorimetric method for the determination of pomalidomide was developed and validated based on the measurement of its native fluorescence without the need for any derivatization and separation for the first time. The fluorescence intensity of the drug in acetonitrile solution allowed precise detection at 460 nm after excitation at 296 nm. The calibration curve was linear in the concentration range 31.0-500.0 ng/ml. Limit of detection and limit of quantification were found to be 8.04 and 24.36 ng/ml, respectively. Sensitive results allowed the drug to be detected with good recovery (75.46-109.72%) in human plasma and urine using the developed method. The proposed method was validated in terms of linearity, sensitivity, precision, accuracy, recovery, and stability parameters. Pomalidomide was subjected to degradation under various stress conditions (hydrolytic, oxidative and thermal) to demonstrate that the method was stable, indicating and identifying possible degradation products. In addition, the drug was exposed to electrochemical degradation using the chronoamperometry technique for the first time. Characterization of pomalidomide degradation products obtained because of oxidative degradation and electrochemical degradation was carried out using attenuated total reflection Fourier transform infrared spectroscopy, mass spectrometry and high performance liquid chromatography - mass spectrometry methods and possible structures were proposed.
Asunto(s)
Talidomida/análogos & derivados , Técnicas Electroquímicas , Humanos , Oxidación-Reducción , Espectrometría de Fluorescencia , Talidomida/sangre , Talidomida/metabolismo , Talidomida/orinaRESUMEN
Bizarre-appearing gingival recessions that do not correspond to any known gingival disease or oral manifestation of any known systemic disease are called factitial (self-induced) gingival disease. Psychological factors are very important in their etiology. Generally, the lesions occur during the time the child is experiencing stress associated with the frustration of his or her dependency needs. Four cases of self-induced gingival recessions involving children aged 4 to 6 years are presented and investigated from the pedodontic, periodontologic, and psychiatric viewpoints.