Internal Standard an Important Analyte Use in Drug Analysis by Liquid Chromatography Mass Spectrometry- An Article

Internal standard is an external compound which is mixed with targeted analytical solution and matrix as a constant concentration and use for preparing calibration standard curve by using ratio of analyte area and internal standard area with analyte concentration and internal standard concentration. This calibration curve used for quantification of unknown concentration of anlayte of interest. This article provide necessary information about internal standard like its selection procedure, characterization, types and response factor , to all analyst who are connected with drug analysis. This article is more important and I think first article which focuses a clear idea about internal standard use in drug analysis.

Using Latent Dirichlet Allocation and Text Mining Techniques for Understanding Medical Literature

Over the past few years, numerous studies and research articles have been published in the medical literature review domain. The topics covered by these researches included medical information retrieval, disease statistics, drug analysis, and many other fields and application domains. In this paper, we employ various text mining and data analysis techniques in an attempt to discover trending topics and topic concordance in the healthcare literature and data mining field. This analysis focuses on healthcare literature and bibliometric data and word association rules applied to 1945 research articles that had been published between the years 2006 and 2019. Our aim in this context is to assist saving time and effort required for manually summarizing large-scale amounts of information in such a broad and multi-disciplinary domain. To carry out this task, we employ topic modeling techniques through the utilization of Latent Dirichlet Allocation (LDA), in addition to various document and word embedding and clustering approaches. Findings reveal that since 2010 the interest in the healthcare big data analysis has increased significantly, as demonstrated by the five most commonly used topics in this domain.

Chiral FexCuySe nanoparticles as peroxidase mimics for colorimetric detection of 3, 4-dihydroxy-phenylalanine enantiomers

L-3,4-dihydroxy-phenylalanine (L-dopa) is the most widely used drug in Parkinson's disease treatment. However, development of cost-effective and high-throughput sensors to accurate enantioselective discrimination of L-dopa and D-dopa remains challenging to date. Herein, on the basis of the peroxidase-mimic activity of chiral FexCuySe nanoparticles, we demonstrated a novel colorimetric sensor for determination of chiral dopa. The surface chiral ligand, L/D-histidine (L/D-His), endowed the nanozymes with enantioselectivity in catalyzing the oxidation of dopa enantiomers. According to the values of kcat/Km, the efficiency of L-His modified nanoparticle (L-FexCuySe NPs) towards L-dopa was 1.56 times higher than that of D-dopa. While, D-His can facilely reverse the preference of the nanozyme to D-dopa. On the basis of high catalytic activity and enantioselectivity of L-FexCuySe NPs in oxidation of L-dopa, the L-FexCuySe NPs based system can be utilized for detection of L-dopa. The linear ranges for L-dopa determination were 5 µM to 0.125 mM and 0.125 mM to 1 mM with a detection limit of 1.02 µM. Critically, the developed sensor has been successfully applied in the quality control of clinical used L-dopa tablets. Our work sheds light on developing simple and sensitive chiral nanomaterials-based sensors for drug analysis.

SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF PHENYLEPHRINE HYDROCHLORIDE AND NAPHAZOLINE HYDROCHLORIDE IN EYE DROPS BY CHEMOMETRIC TECHNIQUES AND ARTIFICIAL NEURAL NETWORK

Three multivariate calibration-prediction techniques, partial least squares (PLS), principal component regression (PCR) and artifi cial neural networks (ANN), have been applied without separation in the spectrophotometric multi-component analysis of phenylephrine hydrochloride and naphazoline hydrochloride. A set of 25 synthetic mixtures of phenylephrine hydrochloride and naphazoline hydrochloride has been evaluated to determine the predictability of PLS, PCR and ANN. The absorbance data matrix was obtained by measuring zero-order absorbances between 230-300 nm at intervals of 3 nm. The suitability of the models was determined on the basis of root mean square error (RMSE), root mean squared cross validation error (RMSECV) and root mean squared prediction error (RMSEP) values of calibration and validation data. The results showed a very good correlation between true values and the predicted concentration values. Therefore, the methods developed can be used for routine drug analysis without chemical pre-treatment.

Bio-Analytical Stability Studies of Nadolol Material

The best practices of Bio-analytical stability studies on drug samples are very crucial and essential for the drugs development process as it specify the acceptancy, purity, efficacy, prediction of strength and quality of the drugs. The main objective of this stability studies on Nadolol the proposed approach of chromatographic separation was administered in isocratic way by using asymmetric C18 column of 40:60 percent of acetonitrile and 0.1% OPA at a flow rate of 1 ml/min is a quantitative measure for drug analysis in biological matrix for more reliable, selective, reproducible and sensitive. This stability study constituents several methods like Bench-Top, Auto-sampler, Freeze-Thaw, Dry-extract, Wet-extract, Short-term, long-Term stability studies at various intervals gave the complete stability information about these drugs. The results of these stability studies are accepted based on ICH guidelines represents this drug has a good stability under the present experimental conditions.

Practical aspect of dimer adduct formation in small-molecule drug analysis with LC-MS/MS

Aim: Since the MS/MS based detection of small-molecule drugs with poor or even no ion fragmentation is a challenge in bioanalysis, alternative MS/MS detection strategies were in focus of this study and applied in the field of forensic toxicology. Material & methods: Analyte quantification with liquid chromatography-tandem mass spectrometry of problematic drugs was studied by the application of dimer adduct formation and valproic acid (VPA) was used as a model drug. VPA adduct ions could be identified during infusion experiments and the VPA dimer adduct ion was optimized for the detection. Conclusion: Dimer adduct ion formation can be used as an effective way of VPA quantification in human serum. Further, the parallel detection of dimer adduct ions with other adduct ion types can be stated as advantage in LC-MS/MS analysis of problematic drugs.