Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidati...Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidative （OXI） degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra （D4） which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one （DD-RD） by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method （DD-DR1） at 243.2 nm, while method D is the mean centering of ratio spectra （MCR） at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression （PCR） and partial least-squares （PLS）, respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.展开更多
Comprehensive analytical methodologies are exceedingly needed in order to evaluate product quality and raw material specifications especially for botanical preparations. Advances in teaming up statistical (PCA, CA &am...Comprehensive analytical methodologies are exceedingly needed in order to evaluate product quality and raw material specifications especially for botanical preparations. Advances in teaming up statistical (PCA, CA & pattern recognition techniques) and spectroscopic (UV, IR, MS & NMR) methods of analysis have generated a substantial impact on how to use spectroscopic instruments as intelligent modules capable of identifying and classifying the composition of a variety of natural products. Cymbopogon proximus, a traditionally used medicinal herb claimed to be an effective remedy for renal spasms, lacks appropriate evaluation procedures. UV assisted-PCA and PLS analysis were exercised herein to maximize the usefulness and applicability of some previously established analytical specifications for herbal materials (e.g. solvent extractive values). Hierarchical cluster analysis was also attempted to categorize and associate the generated solvent-extracts. In addition, DE-TLC and GC were used to examine the different plant fractions in a qualitative and quantitative manner.展开更多
文摘Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidative （OXI） degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra （D4） which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one （DD-RD） by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method （DD-DR1） at 243.2 nm, while method D is the mean centering of ratio spectra （MCR） at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression （PCR） and partial least-squares （PLS）, respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.
文摘Comprehensive analytical methodologies are exceedingly needed in order to evaluate product quality and raw material specifications especially for botanical preparations. Advances in teaming up statistical (PCA, CA & pattern recognition techniques) and spectroscopic (UV, IR, MS & NMR) methods of analysis have generated a substantial impact on how to use spectroscopic instruments as intelligent modules capable of identifying and classifying the composition of a variety of natural products. Cymbopogon proximus, a traditionally used medicinal herb claimed to be an effective remedy for renal spasms, lacks appropriate evaluation procedures. UV assisted-PCA and PLS analysis were exercised herein to maximize the usefulness and applicability of some previously established analytical specifications for herbal materials (e.g. solvent extractive values). Hierarchical cluster analysis was also attempted to categorize and associate the generated solvent-extracts. In addition, DE-TLC and GC were used to examine the different plant fractions in a qualitative and quantitative manner.
