Journal of Pharmaceutical Analysis

Analytical methodologies for determination of methotrexate and its metabolites in pharmaceutical, biological and environmental samples

Forough Karami, Sara Ranjbar, Younes Ghasemi, Manica Negahdaripour

2019, 9(6): 373-391.

Abstract(128) PDF(6)

Abstract:
Methotrexate (MTX) is a folate antagonist drug used for several diseases, such as cancers, various ma-lignancies, rheumatoid arthritis (RA) and inflammatory bowel disease. Due to its structural features, including the presence of two carboxylic acid groups and its low native fluorescence, there are some challenges to develop analytical methods for its determination. MTX is metabolized to 7-hydroxymethotrexate (7-OH-MTX), 2,4-diamino-N10-methylpteroic acid (DAMPA), and the active MTX polyglutamates (MTXPGs) in the liver, intestine, and red blood cells (RBCs), respectively. Additionally, the drug has a narrow therapeutic range; hence, its therapeutic drug monitoring (TDM) is necessary to regulate the pharmacokinetics of the drug and to decrease the risk of toxicity. Due to environmental toxicity of MTX; its sensitive, fast and low cost determination in workplace environments is of great interest. A large number of methodologies including high performance liquid chromatography equipped with UV-visible, fluorescence, or electrochemical detection, liquid chromatography-mass spectroscopy, capillary electrophoresis, UV-visible spectrophotometry, and electrochemical methods have been developed for the quantitation of MTX and its metabolites in pharmaceutical, biological, and environ-mental samples. This paper will attempt to review several published methodologies and the instru-mental conditions, which have been applied to measure MTX and its metabolites within the last decade.

Comparative analysis of twenty-five compounds in different parts of Astragalus membranaceus var. mongholicus and Astragalus membranaceus by UPLC-MS/MS

Yuan Li, Sheng Guo, Yue Zhu, Hui Yan, Da-Wei Qian, Han-Qing Wang, Jian-Qiang Yu, Jin-Ao Duan

2019, 9(6): 392-399.

Abstract(179) PDF(14)

Abstract:
As a traditional Chinese medicine, the root of Astragalus membranaceus var. mongholicus (AMM) or A. membranaceus (AM) has been widely used in China and other Asian countries for thousands of years. Till now, the flavonoids, phenolic acids and saponins are considered as the main active components contributing to their therapeutic effect in these plants. In order to clarify the distribution and contents of these compounds in different organs of these plants, a rapid and sensitive analytical method for simultaneous determination of 25 active compounds including seven types (i.e. dihydroflavones, iso-flavane, isoflavones, flavones, pterocarpans, phenolic acid and saponins) within 10 min was established using ultra-pressure liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Then, the established method was fully validated and successfully applied to the determination of the contents of these analytes in different parts (root, rhizome, stem, leaf and flower) of AMM and AM. The results indicated that the contents of the same type of compounds in two different species plants were significantly different. Moreover, the obvious differences were also found for the distribution and con-tents of different type of compounds in five organs of the same species. The present study could provide necessary information for the rational development and utilization of AMM and AM resource.

FITC labeling of human insulin and transport of FITC-insulin conjugates through MDCK cell monolayer

Darshana Shah, Yuxing Guo, Joseph Ocando, Jun Shao

2019, 9(6): 400-405.

Abstract(112) PDF(1)

Abstract:
Fluorescein isothiocyanate-labeled insulin (FITC-insulin) has been widely used for bioanalytical appli-cations. Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature, there is still a need to develop a cost effective, reliable and quick labeling method for insulin. The purpose of the present work was to develop a quick and affordable method for FITC labeling of human insulin and to determine the effect of different conjugations of FITC to human insulin on its permeability through the MDCK cell monolayer. FITC labeling of insulin gives mono-, di-or tri-conjugates depending on the reaction time and the molar ratio of FITC:insulin. Mono-conjugate with unlabeled insulin, mixture of di-and tri-conjugate, and tri-conjugate with very little amount of di-conjugate were synthesized in less than 4 h. Degree of conjugation had an effect on the permeability of insulin through the MDCK cell monolayer. Mono-conjugate had higher permeability than the unlabeled insulin due to increase in partition coefficient. However, tri-conjugate showed lower permeability than the unlabeled insulin due to the increase in molecular weight.

Quality control of Semen Ziziphi Spinosae standard decoction based on determination of multi-components using TOF-MS/MS and UPLC-PDA technology

Di Wang, Qing Li, Ran Liu, Huarong Xu, Yidi Yin, Yifan Wang, Huijia Wang, Kaishun Bi

2019, 9(6): 406-413.

Abstract(205) PDF(7)

Abstract:
A sensitive, fast and comprehensive method for the quality assessment of Semen Ziziphi Spinosae (SZS) standard decoction with characterization of its chemical components was developed and validated. UPLC-Q/TOF-MS/MS system was used to identify thirty-six chemical components of SZS standard de-coction which included nucleosides, phenolic acids, alkaloids, and flavonoids. Furthermore, a UPLC-PDA method was validated to simultaneously determine adenosine, protocatechuic acid, magnoflorine, ca-techin, protocatechin, vicenin II, spinosin, kaempferol-3-rutinoside, and 6'''-feruloylspinosin which re-present four species of characteristic compounds. The qualitative method had been validated according to Chinese Pharmacopoeia (2015 edition) in terms of lineary, repeatability, recovery and stability for all analytes, with the results showing good precision, accuracy and stability. In conclusion, the method using UPLC combined with MS and PDA provided a novel way for the standardization and identification of SZS standard decoction, and also offered a basis for qualitative analysis and quality assessment of the pre-parations for SZS standard decoction.

Estimation of boswellic acids in herbal formulations containing Boswellia serrata extract and comprehensive characterization of secondary metabolites using UPLC-Q-Tof-MSe

Kumar Katragunta, Bandi Siva, Niharika Kondepudi, P.R. Rao Vadaparthi, Nadendla Rama Rao, Ashok Kumar Tiwari, Katragadda Suresh Babu

2019, 9(6): 414-422.

Abstract(216) PDF(7)

Abstract:
Boswellia serrata is a widely used herb in Indian systems of medicine and is well known for its potential medicinal properties. A chromatographic method was developed for the analysis and quantification of six boswellic acid marker compounds, i.e., keto boswellic acid (1), 3-O-Acetyl 11-keto β-boswellic acid (2), ɑ-Boswellic acid (3), β-Boswellic acid (4), 3-O-Acetyl-ɑ-boswellic acid (5) and 3-O-Acetyl-β-boswellic acid (6) in commercial herbal products containing B. serrata as an ingredient. Combining UPLC with Q-Tof-MS/MS makes the better identification of secondary metabolites and adulterants in the herbal formulations containing B. serrata in rapid time using fragmentation approach than the traditional approaches. In this study quantification of boswellic acids with UPLC-PDA method was performed as per the pharmacopeia guidelines. Furthermore, minor phytochemical constituents were identified and characterized with the help of LC-Q-Tof-MS/MS fragmentation data and various isoforms of boswellic acids and tirucallic acids in B. serrata oleo-gum-resin extract were identified.

Study on degradation kinetics of epalrestat in aqueous solutions and characterization of its major degradation products under stress degradation conditions by UHPLC-PDA-MS/MS

Hong Sun, Suyan Liu, Xun Gao, Zhili Xiong, Zhonggui He, Longshan Zhao

2019, 9(6): 423-430.

Abstract(79) PDF(6)

Abstract:
Drug stability is closely related to drug safety and needs to be considered in the process of drug production, package and storage. To investigate the stability of epalrestat, a carboxylic acid derivative, a reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed in this study and applied to analyzing the degradation kinetics of epalrestat in aqueous solutions in various conditions, such as dif-ferent pH, temperatures, ionic strengths, oxidation and irradiation. The calibration curve was A=1.6 × 105C–1.3 × 103 (r=0.999) with the liner range of 0.5–24 μg/mL, the intra-day and inter-day precision was less than 2.0%, as was the repeatibility. The average accuracy for different concentrations was more than 98.5%, indicating that perfect recoveries were achieved. Degradation kinetic parameters such as degradation rate constants (k), activation energy (Ea) and shelf life (t0.9) under different conditions were calculated and discussed. The results indicated that the degradation behavior of epalrestat was pH-dependent and the stability of epalrestat decreased with the rised irradiation and ionic strength;however, it was more stable in neutral and alkaline conditions as well as lower temperatures. The results showed that the degradation kinetics of epalrestat followed first-order reaction kinetics. Furthermore, the degradation products of epalrestat under stress conditions were identified by UHPLC-PDA-MS/MS, with seven degradation products being detected and four of them being tentatively identified.

Quantitative analysis of 3-isopropylamino-1,2-propanediol as a degradation product of metoprolol in pharmaceutical dosage forms by HILIC-CAD

Qun Xu, Shane Tan

2019, 9(6): 431-436.

Abstract(91) PDF(8)

Abstract:
Aryloxypropanolamine is an essential structural scaffold for a variety of β-adrenergic receptor antago-nists such as metoprolol. Molecules with such a structural motif tend to degrade into α, β-hydroxypropanolamine impurities via a radical-initiated oxidation pathway. These impurities are typically polar and nonchromophoric, and are thus often overlooked using traditional reversed phase chromatography and UV detection. In this work, stress testing of metoprolol confirmed the generation of 3-isopropylamino-1,2-propanediol as a degradation product, which is a specified impurity of metoprolol in the European Pharmacopoeia (impurity N). To ensure the safety and quality of metoprolol drug products, hydrophilic interaction chromatography (HILIC) methods using Halo Penta HILIC column (150 mm×4.6 mm, 5 μm) coupled with charged aerosol detection (CAD) were developed and optimized for the separation and quantitation of metoprolol impurity N in metoprolol drug products including metoprolol tartrate injection, metoprolol tartrate tablets, and metoprolol succinate extended-release tablets. These HILIC-CAD methods were validated per USP validation guidelines with respect to speci-ficity, linearity, accuracy, and precision, and have been successfully applied to determine impurity N in metoprolol drug products.

Nuclear magnetic resonance based structure of the protoberberine alkaloid coralyne and its self-association by spectroscopy techniques

Kumar Padmapriya, Ritu Barthwal

2019, 9(6): 437-448.

Abstract(93) PDF(2)

Abstract:
Coralyne is an important alkaloid due to its anti-cancer and other medicinal properties. It targets DNA in cells and acts as human topoisomerase-I poison, telomerase inhibitor and nucleic acid intercalator. It has high tendency to undergo self-association, which is a matter of concern for therapeutic applications. The understanding of its interaction with DNA requires precise knowledge of chemical shifts in Nuclear Magnetic Resonance (NMR) spectra besides self-association. The present study is the first report of a complete assignment of all 1H/13C resonances in NMR spectra of coralyne in DMSO-d6 using one dimensional 1H/13C and two dimensional NMR experiments. The chemical shift of all proton and several 13C resonances have also been obtained in D2O and ethanol-d6. The same has been calculated using Density Functional Theory (DFT). NMR spectra of coralyne show upfield shift of 0.6-1.2 ppm in aromatic ring protons suggesting stacking interactions. Apart from 11 intra molecular NOE cross peaks in 2D 1H-1H ROESY spectra, 3 short distance NOE correlations, H6-10OCH3, H5-10OCH3 and H12-16CH3, give direct independent evidence of the formation of a stacked dimer. The absorbance, fluorescence, circular dichroism and fluorescence lifetime experiments conducted in the present investigations corroborate results obtained by NMR.

Instructions to Authors Journal of Pharmaceutical Analysis

2019, 9(6): 449-450.

Abstract(84) PDF(3)

Abstract:

2019 Vol. 9, No. 6