Journal of Pharmaceutical Analysis

2018, 8(3)

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Abstract:

Overview of the detection methods for equilibrium dissociation constant KD of drug-receptor interaction

Weina Ma, Liu Yang, Langchong He

2018, 8(3): 147-152.

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Abstract:
Drug-receptor interaction plays an important role in a series of biological effects, such as cell pro-liferation, immune response, tumor metastasis, and drug delivery. Therefore, the research on drug-re-ceptor interaction is growing rapidly. The equilibrium dissociation constant (KD) is the basic parameter to evaluate the binding property of the drug-receptor. Thus, a variety of analytical methods have been established to determine the KD values, including radioligand binding assay, surface plasmon resonance method, fluorescence energy resonance transfer method, affinity chromatography, and isothermal ti-tration calorimetry. With the invention and innovation of new technology and analysis method, there is a deep exploration and comprehension about drug-receptor interaction. This review discusses the differ-ent methods of determining the KD values, and analyzes the applicability and the characteristic of each analytical method. Conclusively, the aim is to provide the guidance for researchers to utilize the most appropriate analytical tool to determine the KD values.

Quantification and pharmacokinetic study of tumor-targeting agent MHI148-clorgyline amide in mouse plasma using liquid chromatography-electrospray ionization tandem mass spectrometry

Zhijun Wang, Bogdan Z. Olenyuk, Jean Chen Shih, Jeffrey Wang

2018, 8(3): 153-159.

Abstract(98) PDF(3)

Abstract:
A high-performance liquid chromatography-electrospray ionization tandem mass spectrometric (HPLC-ESI-MS/MS) method was developed for the quantification of MHI148-clorgyline amide (NMI-amide), a novel tumor-targeting monoamine oxidase A inhibitor, in mouse plasma. The method was validated in terms of sensitivity, precision, accuracy, recovery and stability and then applied to a pharmacokinetic study of NMI-amide in mice following intravenous administration. NMI-amide together with the internal standard (IS), MHI-148, was extracted by protein precipitation using acetonitrile. Multiple reaction monitoring was used for quantification of NMI-amide by detecting m/z transition of 491.2–361.9, and 685.3–258.2 for NMI-amide and the IS, respectively. The lower limit of quantification (LLOQ) of the HPLC–MS/MS method for NMI-amide was 0.005 μg/mL and the linear calibration curve was acquired with R2> 0.99 in the concentration range of 0.005–2 μg/mL. The intra- and inter-day precisions of the assay were assessed by percentage of the coefficient of variations, which was within 9.8% at LLOQ and 14.0% for other quality control samples, whereas the mean accuracy ranged from 86.8% to 113.2%. The samples were stable under storage and experimental conditions. This method was successfully applied to a pharmacokinetic study in mice following intravenous administration of 5 mg/kg NMI-amide.

Simultaneous determination of acetaminophen and oxycodone in human plasma by LC–MS/MS and its application to a pharmacokinetic study

Wei Lu, Shunbo Zhao, Meng Gong, Luning Sun, Li Ding

2018, 8(3): 160-167.

Abstract(159) PDF(3)

Abstract:
A simple and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was de-veloped and validated for simultaneous determination of acetaminophen and oxycodone in human plasma. Acetaminophen-d4 and oxycodone-d3 were used as internal standards. The challenge en-countered in the method development that the high plasma concentration level of acetaminophen made the MS response saturated while the desired lower limit of quantification (LLOQ) for oxycodone was hard to reach was well solved. The analytes were extracted by protein precipitation using acetonitrile. The matrix effect of the analytes was avoided by chromatographic separation using a hydrophilic C18 column coupled with gradient elution. Multiple reaction monitoring in positive ion mode was performed on tandem mass spectrometer employing electrospray ion source. The calibration curves were linear over the concentration ranges of 40.0–8000 ng/mL and 0.200–40.0 ng/mL for acetaminophen and oxycodone, respectively. This method, which could contribute to high throughput analysis and better clinical drug monitoring, was successfully applied to a pharmacokinetic study in healthy Chinese volunteers.

Evaluation of physicochemical properties as supporting information on quality control of raw materials and veterinary pharmaceutical formulations

Sara da Silva Anacleto, Marcella Matos Cordeiro Borges, Hanna Leijoto de Oliveira, Andressa Reis Vicente, Eduardo Costa de Figueiredo, Marcone Augusto Leal de Oliveira, Bárbara Juliana Pinheiro Borges, Marcelo Antonio de Oliveira, Warley de Souza Borges, Keyller Bastos Borges

2018, 8(3): 168-175.

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Abstract:
This study aimed to show that the physicochemical proprieties obtained by Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and scanning electronic microscopy (SEM) can be useful tools for evaluating the quality of active pharmaceutical ingredients (APIs) and pharmaceutical products. In addition, a simple, sensitive, and efficient method employing HPLC-DAD was developed for simulta-neous determination of lidocaine (LID), ciprofloxacin (CFX) and enrofloxacin (EFX) in raw materials and in veterinary pharmaceutical formulations. Compounds were separated using a Gemini C18 (250 mm × 4.6 mm, 5 μm) Phenomenex ? column, at a temperature of 25 °C, with a mobile phase containing 10 mM of phosphoric acid (pH 3.29): acetonitrile (85.7:14.3, v/v) and a flow rate of 1.5 mL/min. Physicochemical characterization by TG, FTIR, and SEM of raw materials of LID, CFX, and EFX provided information useful for the evaluation, differentiation, and qualification of raw materials. Finally, the HPLC method was proved to be useful for evaluation of raw material and finished products, besides satisfying the need for an analytical method that allows simultaneous determination of EFX, CFX, and LID, which can also be extended to other matrices and applications.

Identification of three kinds of Plumeria flowers by DNA barcoding and HPLC specific chromatogram

Leilei Zhao, Xiaoxue Yu, Jie Shen, Xinjun Xu

2018, 8(3): 176-180.

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Abstract:
DNA barcoding and HPLC specific chromatogram were used to identify three kinds of Plumeria flowers respectively. DNAs extracted from the three Plumeria species were amplified by PCR with universal primers, and the psbA-trnH region was selected. All the amplified products were sequenced and the results were analyzed by MEGA 5.0. Chemometric methods including principal components analysis and hierarchical clustering analysis were conducted on the SAS 9.0 software to demonstrate the variability among samples. In conclusion, the psbA-trnH of all samples were successfully amplified from total DNA and sequenced. These three varieties of Plumeria can be differentiated by the psbA-trnH region and clustered into three groups respectively through building neighbor joining tree, which conformed to their germplasm origins. However, it was hard to distinguish them by HPLC specific chromatograms combined with chemometrics analysis. These indicated that DNA barcoding was a promising and reliable tool for the identification of three kinds of Plumeria flowers compared to HPLC specific chromatogram generally used. It could be treated as a powerful complementary method for traditional authentication, especially for those varieties which are difficult to be identified by conventional chromatography.

Enhancing the dissolution of phenylbutazone using Syloid? based mesoporous silicas for oral equine applications

Laura J. Waters, John P. Hanrahan, Joseph M. Tobin, Catherine V. Finch, Gareth M.B. Parkes, Shamsuddeen A. Ahmad, Faraj Mohammad, Maria Saleem

2018, 8(3): 181-186.

Abstract(76) PDF(1)

Abstract:
Three mesoporous silica excipients (Syloid? silicas AL-1 FP, XDP 3050 and XDP 3150) were formulated with a model drug known for its poor aqueous solubility, namely phenylbutazone, in an attempt to enhance the extent and rate of drug dissolution. Although other forms of mesoporous silica have been investigated in previous studies, the effect of inclusion with these specific Syloid? silica based excipients and more interestingly, with phenylbutazone, is unknown. This work reports a significant enhancement for both the extent and rate of drug release for all three forms of Syloid? silica at a 1:1 drug:silica ratio over a period of 30 min. An explanation for this increase was determined to be conversion to the amorphous form and an enhanced drug loading ability within the pores. Differences between the release profiles of the three silicas were concluded to be a consequence of the physicochemical differences between the three forms. Overall, this study confirms that Syloid? silica based excipients can be used to enhance dissolution, and potentially therefore bioavailability, for compounds with poor aqueous solubility such as phenylbutazone. In addition, it has been confirmed that drug release can be carefully tailored based on the choice of Syloid? silica and desired release profile.

Enrichment and immobilization of macromolecular analytes on a porous membrane utilizing permeation drag

Pedram Madadkar, Rahul Sadavarte, Raja Ghosh

2018, 8(3): 187-193.

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Enrichment and immobilization of analytes by chemical bonding or physical adsorption is typically the first step in many commonly used analytical techniques. In this paper, we discuss a permeation drag based technique as an alternative approach for carrying out location-specific immobilization of macro-molecular analytes. Fluorescein isothiocyanate (FITC) labeled macromolecules and their complexes were enriched near the surface of ultrafiltration membranes and detected by direct visual observation and fluorescence imaging. The level of macromolecule enrichment at the immobilization sites could be controlled by manipulating the filtration rate and thereby the magnitude of permeation drag. Higher enrichment as indicated by higher fluorescence intensity was observed at higher filtration rates. Also, larger macromolecules were more easily enriched. The feasibility of using this technique for detecting immunocomplexes was demonstrated by carrying out experiments with FITC labeled bovine serum al-bumin (FITC-BSA) and its corresponding antibody. This permeation drag based enrichment technique could potentially be developed further to suit a range of analytical applications involving more sophis-ticated detection methods.

Physics, chemistry, and Hirshfeld surface analyses of gamma-irradiated thalidomide to evaluate behavior under sterilization doses

Valner A.F.S.N. Mussel, Max P. Ferreira, Maria B.F. Marques, Maria I. Yoshida, Mariana R. Almeida, Bernardo L. Rodrigues, Wagner N. Mussel

2018, 8(3): 194-201.

Abstract(46) PDF(0)

Abstract:
Thalidomide was indicated as a sedative and antiemetic and prescribed for pregnant women. Its tragic teratogenic effects culminated in withdrawal from the market. Since the discovery of its anti-angiogenic and anti-inflammatory actions, thalidomide has been used in the treatment of leprosy and multiple myeloma, which justify studies of its stability. We investigated the effects of irradiation of thalidomide up to 100 kGy (fourfold the usual sterilizing dose for pharmaceutics). The β polymorph of thalidomide was obtained in an isothermal experiment at 270 °C. All samples underwent gamma irradiation for specific times. At different doses, decomposition of the pharmaceutical was not observed up to 100 kGy. The observed effect was angle turning between the phthalimide and glutarimide rings modulated by repulsion towards the carbonyl group, leading to a stable energetic configuration, as measured by the equilibrium in the torsion angle after irra-diation. The thalidomide molecule has a center of symmetry, so a full turn starting from 57.3° will lead to an identical molecule. Further irradiation will start the process again. Samples irradiated at 30 and 100 kGy have more compact unit cells and a lower volume, which leads to an increase in the intermolecular hydrogen interaction within the unit cel , resulting in higher thermal stability for polymorph α.

Sensitive and rapid determination of amantadine without derivatization in human plasma by LC–MS/MS for a bioequivalence study

Abhaysingh Bhadoriya, Shivprakash Rathnam, Bhavesh Dasandi, Dharmesh Parmar, Mallika Sanyal, Pranav S. Shrivastav

2018, 8(3): 202-207.

Abstract(106) PDF(1)

Abstract:
A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for reliable estimation of amantadine (AMD), an antiviral drug in human plasma. The analyte and internal standard (IS), amantadine-d6 (AMD-d6), were extracted from 200 μL plasma by solid phase extraction on Phenomenex Strata-X-C 33 μ cartridges. Chromatography was performed on Synergi? Hydro-RP C18 (150 mm × 4.6 mm, 4 μm) analytical column using a mixture of acetonitrile and 10 mM ammonium formate, pH 3.0 (80:20, v/v) as the mobile phase. Detection and quantitation was done by multiple reaction monitoring in the positive ionization mode for AMD (m/z 152.1 → 135.1) and IS (m/z 158.0 → 141.1) on a triple quadrupole mass spectrometer. The assay was linear in the concentration range of 0.50–500 ng/mL with correlation coefficient (r2) ≥ 0.9969. The limit of detection of the method was 0.18 ng/mL. The intra-batch and inter-batch precisions were ≤ 5.42% and the accuracy varied from 98.47% to 105.72%. The extraction recovery of amantadine was precise and quantitative in the range of 97.89%–100.28%. IS-normalized matrix factors for amantadine varied from 0.981 to 1.012. The stability of AMD in whole blood and plasma was evaluated under different conditions. The developed method was successfully applied for a bioequivalence study with 100 mg of AMD in 32 healthy volunteers. The re-producibility of the assay was determined by reanalysis of 134 subject samples.

2018 Vol. 8, No. 3