Kaho Kwok

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Counterfeit medicines have become a serious global problem. Consequently, analytical and pharmaceutical scientists have been active in developing and applying new methodologies to detect and analyze counterfeit medicines. Vibrational spectroscopy combined with chemometric methods is becoming a popular choice in this area of research. In this study, Raman(More)
Previous studies have shown that deliquescent organic compounds frequently exhibit chemical instability when stored in environmental conditions above their deliquescence relative humidity (RH). The goal of the current study was to investigate the effect of atmospheric moisture on the long-term chemical stability of crystalline sucrose-citric acid mixtures(More)
Identifying pharmaceutical ingredients is a routine procedure required during industrial manufacturing. Here we show that a recently developed Raman compressive detection strategy can be employed to classify various widely used pharmaceutical materials using a hybrid supervised/unsupervised strategy in which only two ingredients are used for training and(More)
To investigate the heating-induced dehydration and melting behavior of the trihydrate phase of the calcium salt of atorvastatin. Multivariate curve resolution (MCR) was used to decompose a variable-temperature synchrotron X-ray powder diffraction (VT-XRPD) data matrix into diffraction patterns and concentration profiles of pure drug phases. By means of the(More)
The combination of ultrasonic nebulization with membrane desolvation (USN-MD) is utilized to determine active pharmaceutical ingredients (API) by heteroatom inductively coupled mass spectroscopy (ICP-MS) detection. Ultrasonic nebulization provides efficient sampling while use of the membrane desolvator acts to reduce solvent-based interferences. This(More)
Atomic spectrometry, specifically inductively coupled plasma atomic emission spectrometry (ICP-AES) and mass spectrometry (ICP-MS) show promise for heteroatom-based detection of pharmaceutical compounds. The combination of ultrasonic nebulization (USN) with membrane desolvation (MD) greatly enhances detection limits with these approaches. Because(More)
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