Search

Liquid chromatography coupled to mass spectrometry already started to surpass the major drawbacks in terms of sensitivity, specificity and cross-reactivity that some analytical methods used in the clinical laboratory exhibit. This hyphenated technique is already preferred for specific applications while finding its own place in the clinical laboratory setting. However, large-scale usage, high-throughput analysis and lack of automation emerge as shortcomings that liquid chromatography coupled to mass spectrometry still has to overrun in order to be used on a larger scale in the clinical laboratory. The aim of this review article is to point out the present-day position of the liquid chromatography coupled to mass spectrometry technique while trying to understand how this analytical method relates to the basic working framework of the clinical laboratory. This paper offers insights about the main regulation and traceability criteria that this coupling method has to align and comply to, automation and standardization issues and finally the critical steps in sample preparation workflows all related to the high-throughput analysis framework. Further steps are to be made toward automation, speed and easy-to-use concept; however, the current technological and quality premises are favorable for chromatographic coupled to mass spectral methods. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a reversed-phase HPLC method for the simultaneous determination of metformin and pioglitazone in pharmaceutical dosage forms and impurities HPLC profiling of two pioglitazone and three metformin impurities, in the presence of their parent compound. The analytical methods were developed following an optimization from different aspects of the methods available in the correspondent monographs of the European Pharmacopoeia 10.1 edition and that of the United States Pharmacopoeia 43. A C18 column stationary phase and an ion pair former were used to improve the retention of hydrophillic analytes and the most suitable detection wavelength was set at 255 nm. The method was tested by quantitative estimation of active substances from a mixture of commercial tablet powder obtained in a 500:15 metformin:pioglitazone mass ratio. The method for separation of impurities proved to be satisfactory in terms of resolution between peaks, but not in terms of separation efficiency for metformin impurities. [ABSTRACT FROM AUTHOR]

A fost validată o metodă simplă şi selectivă de determinare a genisteinei (GNST) din ficat şi rinichi de şobolan în vederea studierii efectului fitoestrogenic al GNST la șobolani Wistar de sex feminin ovariectomizaţi. GNST a fost separată pe o coloană Kromasil 100-RP8, de 150 mm x 4,6 mm, 5 μm prevăzută cu precoloană Kromasil RP 8. Faza mobilă a fost 55:45 (v/v) acid fosforic 15 mmol în apă : metanol la un debit de 1,3 ml/min. Ca standard intern a fost folosită luteolina 20 μg/ml în metanol. Timpul de retenţie al GNST a fost tR = 13,22 min şi tR = 11,60 min pentru standardul intern. Curbele de calibrare pe domeniul 40-400 μg GNST/100g ficat şi 20-200 μg GNST/100g rinichi au prezentat coeficienţi de determinare ˃0,99. Metoda a prezentat o bună precizie şi acurateţe la limita de cuantificare. 10 şobolani albi Wistar de sex feminin, cu vârsta de 8 săptămâni au fost trataţi s.c. cu 10 mg/kg c/zi soluţie GNST timp de 8 săptămâni, în timp ce un lot de 10 animale au folosit ca martor. Valorile obţinute pentru GNST în ficat au fost 192.12 ± 53.46 μg/100g, iar în rinichi 74.51 ± 12.77 μg/100g.

Orodispersible tablets (ODTs) are pharmaceutical formulations used to obtain fast therapeutic effects, usually recommended for geriatric and pediatric patients due to their improved compliance, bioavailability, ease of administration, and good palatability. This study aimed to develop ODTs with cannabidiol (CBD) phytocannabinoid extracted from Cannabis sativa used in the treatment of Lennox–Gastaut and Dravet syndromes. The tablets were obtained using an eccentric tableting machine and 9 mm punches. To develop CBD ODTs, the following parameters were varied: the Poloxamer 407 concentration (0 and 10%), the type of co-processed excipient (Prosolv® ODT G2—PODTG2 and Prosolv® EasyTab sp—PETsp), and the type of superdisintegrant (Croscarmellose—CCS, and Soy Polysaccharides—Emcosoy®—EMCS), resulting in eleven formulations (O1–O11). The following dependent parameters were evaluated: friability, disintegration time, crushing strength, and the CBD dissolution at 1, 3, 5, 10, 15, and 30 min. The dependent parameters were verified according to European Pharmacopoeia (Ph. Eur.) requirements. All the tablets obtained were in accordance with quality requirements in terms of friability (less than 1%), and disintegration time (less than 180 s). The crushing strength was between 19 N and 80 N. Regarding the dissolution test, only four formulations exhibited an amount of CBD released higher than 80% at 30 min. Taking into consideration the results obtained and using the Modde 13.1 software, an optimal formulation was developed (O12), which respected the quality criteria chosen (friability 0.23%, crushing strength of 37 N, a disintegration time of 27 s, and the target amount of CBD released in 30 min of 99.3 ± 6%). [ABSTRACT FROM AUTHOR]

Clopidogrel is a chiral compound, (+)-(S)-enantiomer has antiplatelet activity, while (-)-(R)-clopidogrel is considered an impurity of the active substance. The development of HPLC methods for optical purity analysis involves the use of expensive chiral columns and the methodologies could be different in the two well recognized compendia, European (Ph.Eur.) and United Stated (USP) Pharmacopoeias. The aim of this study was to optimise the chiral chromatographic assay of clopidogrel and its impurities from tablets taking into consideration the official pharmacopoeia provision by testing the influence of the variation of different chromatographic parameters on the relative retention times of clopidogrel and official impurities in order to achive the separation performance parameters described in USP43. HPLC-UV enantioseparation of clopidogrel was performed on a column with ovomucoid as a stationary phase chiral selector and phosphate - acetonitrile mixtures as mobile phase. The official relative retention of clopidogrel and its A and C impurities could not be achieved in this study, neither by applying a classical optimization methodology nor by using the experimental design methodology which raises the issue of reviewing the pharmacopoeia provisions. A comparative discussion between the two different approaches regarding chiral separation of clopidogrel in Ph.Eur. and USP is provided. [ABSTRACT FROM AUTHOR]

Cannabidiol (CBD) is one of the most studied alkaloids found in Cannabis species. Also, its occurrence in Cannabis plants is higher in most of cases compared with the addictive compound named tetrahydrocannabinol (THC). This study aimed to evaluate CBD concentrations and stability in different commercial products and reconstituted oil. An UHPLC method previously published was applied. Three CBD oils and two powders marketed online together with a reconstituted oil were analyzed. The oils presented concentrations lower than stated on the label. The content of reconstituted CBD oils prepared similarly to the commercial oils decrease linearly with small differences based on the storage conditions. Thus, the CBD oil kept at temperatures of 5±0.3°C tends to decompose slightly slower compared with the oil kept at room temperature. A stabilizer may be needed to slow the decomposition process. Future studies for reconstituted formulation may be needed to establish if the type of oil used is influencing the decomposition process. [ABSTRACT FROM AUTHOR]

A new high-throughput, inexpensive and selective LC-MS method for determining fenbendazole, albendazole and albendazole sulfoxide from human and ovine plasma was developed and validated in accordance with current guidelines in bioanalysis. Analytes (fenbendazole, albendazole, albendazole sulfoxide) and internal standard (fluconazole) were separated on a Gemini NX-C18 analytical column in reversed phase chromatography in gradient elution using mobile phase composed of acetonitrile and aquenous 0.2% formic acid with a flow rate of 0.6 mL/min. After positive electrospray ionization analytes were detected in the mass spectrometer in selected reaction monitoring mode, monitoring fragment ion m/z 268.05 from m/z 300.08 for fenbendazole, ion m/z 234.07 from m/z 266.09 for albendazole, ion m/z 240.04 from m/z 282.09 for albendazole sulfoxide and ion m/z 220.06 from m/z 307.60 for fluconazole. Sample preparation was performed using protein precipitation. Validation of the analytical method was performed with respect to selectivity, stability, linearity (r>0.9901), precision (RSD<12.9%) and accuracy (bias<12.7%) over the concentration ranges of 5-250 ng/mL for each analyte (lower limit of quantification was 5 ng/mL for all analytes). The analytical method is simple, versatile and suitable for bioanalysis of these azole anthelmintic drugs from human and ovine samples, and applicable in pharmacokinetic studies involving fenbendazole and albendazole. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)