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TLC—Densitometric Determination of Sulfasalazine and Its Possible Impurities in Pharmaceutical Preparations

Kwiecień A., Piątek K., Żmudzki P., Krzek J.

Acta Chromatographica

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2015

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Vol. 27, no. 4

623--635

EN

A simple, selective, and sensitive thin-layer chromatographic—densitometric method has been developed for the determination of sulfasalazine besides its possible impurities in pharmaceutical preparations. The mobile phase was composed of ethyl acetate—methanol—ammonia 25% 10:7:3 (υ/υ/υ), and the stationary phase was aluminum plates precoated with silica gel 60 F254 that enabled to obtain well resolved peaks of sulfasalazine and its impurities. The developed chromatograms were analyzed densitometrically at λ = 360 nm. RF values and ultraviolet (UV) spectra were used to identify the compounds. The developed method is highly sensitive (limit of detection [LOD] = 17.11 ng spot−1, limit of quantitation [LOQ] = 51.84 ng spot−1), precise (relative standard deviation [RSD] = 1.43%–4.28%), and accurate (RSD = 1.64%–4.27%). The linearity of the method was checked within the range 20–120 ng spot−1. The method was successfully applied for the determination of sulfasalazine in pharmaceutical preparations besides its impurities. The structures of impurities present in the standard substance and in pharmaceutical preparations were established by ultra-performance liquid chromatography—tandem mass spectrometry (UPLC—MS/MS) technique.

2

Simultaneous identification and quantitative determination of azithromycin, clarithromycin, roxithromycin, spiramycin and troleandomycin by thin-layer chromatography and densitometry

Kwiecień A., Krzek J., Gądek M.

Acta Chromatographica

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2014

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Vol. 26, no. 4

657--670

EN

The purpose of this work was to develop a TLC-densitometric method for simultaneous identification and quantitative determination of azithromycin, clarithromycin, roxithromycin, spiramycin, and troleandomycin. The method was developed on TLC aluminium plates precoated with silica gel F254 using solvent system izopropanol:n-hexane:ammonia 25% (8:12:3, v/v/v), which gives compact spots for azithromycin (RF = 0.65), clarithromycin (RF = 0.54), roxithromycin (RF = 0.49), spiramycin (RF = 0.22), and troleandomycin (RF = 0.36). Densitometric analysis was carried out at 478 nm after spraying with (1:4, v/v) sulphuric acid:ethanol and heating at 100°C for 5 min. The linear regression analysis data for the calibration plots showed good linear relationship with correlation coefficient higher than 0.99. The method is distinguished by high sensitivity, with limit of detection (LOD) from 0.34 μg/spot for troleandomycin to 0.67 μg/spot for clarithromycin and limit of quantification (LOQ) from 1.02 μg/spot for troleandomycin to 2.04 μg/spot for clarithromycin and a wide linearity range from 2 to 12 μg/spot for spiramycin and 2–15 μg/spot for other antibiotics. The precision of the determination was good; relative standard deviation (RSD) varied in the range from 1.49% to 4.14%.

3

Determination of fluoxetine in the presence of photodegradation products appearing during UVA irradiation in a solid phase by chromatographic-densitometric method, kinetics and identification of photoproducts

Maślanka A., Hubicka U., Krzek J., Walczak M., Izworski G.

Acta Chromatographica

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2013

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Vol. 25, no. 3

465--481

EN

An effect of ultraviolet A (UVA) radiation on fluoxetine stability in solid phase with and without the presence of selected metal ions was studied using the chromatographic-densitometric method. Silica gel TLC F254 plates were used as the stationary phase and chloroform-methanol-ammonia 25% (45:4.5:0.5, v/v/v) as the mobile phase. The chromatograms were recorded densitometrically at a wavelength of λ = 260 nm.Both the concentration and kind of an ion have an effect on the photodegradation process. Kinetic studies demonstrated that fluoxetine photodegradation is the fastest in the presence of Cu(II) ions, decreases in the presence of Fe(III) and Fe(II) ions, and is the lowest in the presence of Al(III) ions. Under conditions established without the presence of metal ions, fluoxetine maintains photostability.The liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) method was applied for the identification of decomposition products noting the presence of 3-phenyl-3-hydroxypropylamine and 4-trifluoromethylphenol.

4

Identification and determination of compounds belonging to the group of OUN pharmaceutical agents by thin-layer chromatography with densitometric detection in biological material

Maślanka A., Krzek J., Żuromska B, Stolarczyk M.

Acta Chromatographica

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2011

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Vol. 23, no. 2

247--266

EN

The chromatographic-densitometric method was developed for the simultaneous determination of various pharmaceutical agents, such as haloperidol, fluxetine, promazine, doxepin, clonazepam, alprazolam, and risperidone in biological material. Two mobile phases, A (acetone-diethylamine-cyclohexane (2.5:2.5:20, υ/υ/υ)) and B (trichloromethane-acetone-25% NH3 (25:25:0.5, υ/υ/υ)), were used for the separation of the above-mentioned compounds. Silica gel-covered F254 TLC plates were used as stationary phases. Densitometric recording was carried out at 254 nm wavelength. Well-developed peaks, easy to quantify, and quality analysis were obtained after achieving the separation of compounds in the developed conditions. It was demonstrated that the presence of a matrix (plasma or urine) did not affect the shape of the peaks and their localization on the chromatograms.

5

Evaluation of a CGC-FID method for qualitative and quantitative analysis of azole antifungal drugs

Ekiert R. J., Krzek J., Czekaj J. S., Hubicka U.

Acta Chromatographica

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2009

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Vol. 21, no. 2

273--282

EN

This paper presents a new method for identification and quantitative analysis of six azole antifungal drugs — bifonazole, clotrimazole, econazole, fluconazole, ketoconazole, and miconazole — by capillary gas chromatography (CGC) combined with flame ionization detection (FID). The chromatographic separation conditions were established and the method was validated for precision (RSD = 1.49–3.55%), recovery (98.6–101.2%), and linearity within the range under investigation (∼1.0–33.3 ng). The results obtained show the newly developed procedure is suitable for qualitative and quantitative pharmaceutical analysis of the six azoles.

6

Qualitative and quantitative analysis of hesperidin in tablets by thin layer chromatography with densitometric UV detection

Janeczko Z., Hubicka U., Podolak I., Krzek J.

Chemia Analityczna

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2004

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Vol. 49, No. 3

309-316

EN

Conditions for detection of hesperidin in pharmaceutical formulations, such as Hesperydynin tablets, have been established. Chromatographic separation was performed on 60 F254 silica gel TLC plates with a chloroform-methanol-water (23+12+2, v/v/v) mobile phase. The spots were analysed by UV densitometry at [lambda] ≈ 286 nm. Under the established experimental conditions repeatable and accurate results were obtained. The method proposed is sensitive. It provides detection limit of 20 ng and satisfactory recovery in the range: 99.91%-100.74% for the declared content 100 mg. Linearity was maintained in the broad range from 4 to 44 žg mL-1.

PL

Opracowano warunki identyfikacji hesperydyny w preparatach farmaceutycznych na przykładzie tabletek Hesperydynin. Rozdział chromatograficzny przeprowadzono na pfytkach TLC pokrytych żelem krzemionkowym 60 F(254), z fazą ruchomą o składzie chloroform -metanol woda (23+12+2 v/v/v). Zastosowano detekcję densytometryczną UV przy długości fali Lambda = 286 nm. W zastosowanych warunkach uzyskano dokładne i powtarzalne wyniki oznaczeń. Czułość metody jest wysoka, granica wykrywalności wynosi 20 ng. Odzysk hesperydyny z próbki o deklarowanej zawartości związku 100 mg wahał się w granicach 99.91%-100.74%. Stwierdzono szeroki zakres Siniowości: od 4 do 44 ug mL(-1).

7

Spectrophotometric determination of gentamycin sulfate(VI), dexamethasone and methyl and propyl 4-hydroxybenzoates in pharmaceuticals

Krzek J., Stolarczyk M., Rzeszutko W.

Chemia Analityczna

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2002

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Vol. 47, No. 2

299-309

EN

A quick, simple and accurate method for determination of four constituents in complex pharmaceuticals is presented. For spectroscopic determination ofgentamycin sulfate(VI), the ninhydrin reaction was used, thus enabling measurements at three wavelengths Lambda(316(, Lambda(401) and Lambda(567). The results of high repeatability and accuracy were obtained. It has been found that in some cases the use of derivative absorption spectra leads to more accurate results as compared to those of zero-order spectrophotometry. The recovery for individual constituents was sufficiently high and ranged from 98.8% to 101.2%.

PL

Opisano prostą, szybką i dokładną metodę, spektrofoto netrycznego oznaczania czterech składników w lekach złożonych. Do oznaczeń spektrotbtometrycznych siarczanu(YI) gen-tamycyny wykorzystano reakcję z ninhydryną, uzyskując możliwość wykonania pomiarów przy trzech długościach fal Lambda(316) Lambda 401 i Lambda(567). Otrzymane wyniki cechuje powtarzalność i wysoka precyzja oznaczeń. Stwierdzonojednocześnie, że w niektórych przypadkach wykorzystanie absorpcyjnych widm pochodnych daje pozytywne rezultaty w zakresie dokładności metody, gdzie obserwowano znaczącą redukcję błędów w porównaniu do pomiarów spektrofotometrii zerowego rzędu. Odzysk poszczególnych składników w opracowanych warunkach oznaczania jest wystarczająco wysoki i wynosi od 98.8% do101 .2%.

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Densitometric determination of impurities in pharmaceuticals. Part V. Determination of folic acid and 2,4-diaminopteridine-6-carboxylic acid in methotrexate

Krzek J., Kwiecień A.

Chemia Analityczna

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2000

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Vol. 45, No. 4

551-559

EN

A chromatographic and densitometric method has been developed for the identification and quantitative determination of folic acid and 2,4-diaminopteridine-6-carboxylic acid occurring as impurities in methotrexate. Two mobile phases were used for the separation: glacial acetic acid-dimethylsulfoxide-propanol-2-ammonia 25% (2:8:25:5 v/v) and dimethylsulfoxide-propanol-2-ammonia 25% (7:30:8 v/v) and ready to use HPTLC plates as stationary phase. Detection was carried out directly on plates together with quantitative densitometric measurements in UV at X = 273 nm and fluorimetric at A, = 366 nm. The newly developed method appears to be useful for the direct determination of folic acid and 2,4-diaminopteridine-6-carboxylic acid. Statistical analysis has proved that this method is accurate and repeatable.

PL

Opracowano chromatograficzno -densytometryczną metodę identyfikacji i oznaczania kwasu foliowego i kwasu 2,4-diaminopterydyno-6-karboksylowego występujących jako zanieczyszczenia w preparacie methotreksat. Do rozdziału stosowano dwie fazy ruchome: kwas octowy lodowaty-dimetylosulfotlenek-propanol-2-amoniak 25% (2:8:25:5 v/v) i dimetylosulfotlenek-propanol-2-amoniak 25% (7:30:8 v/v) oraz gotowe płytki HPTLC jako fazę stacjonarną. Detekcję prowadzono bezpośrednio na płytkach, dokonując jednocześnie ilościowych pomiarów densytometrycznych w UV przy X = 273 nm i fluorymetrycznych przy X, = 366 nm. Stwierdzono, że opracowana metoda jest przydatna do oznaczeń bezpośrednich kwasu foliowego i kwasu 2,4-diaminoptery-dyno-6-karboksylowego, jest dokładna i powtarzalna o czym świadczy statystyczna ocena wyników.

9

Spectrophotometric and chromatographic-densitomeytric determination of propoxur in the collars for animals

Krzek J., Stolarczyk M., Maślanka A.

Chemia Analityczna

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1999

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Vol. 44, No. 1

55-60

EN

A spectrophotometric and chromatography-densitometric method has been developed for determination of propoxur (2-isopropoxyphenyl methylcarbamate) in the coIlars for animals. Conditions for the propoxur extraction into various solvents have been deter-mined, and the superiority of methanol and carbon tertrachloride for propoxur determi-nation has been stated. Analysis of real samples proved that these two developed methods can be used for qualitative and a quantitive determination of propoxur in the coIlars for animals, because consistent results were obtained for each of them.

PL

Opracowano spektrofotometryczną oraz chromatograficzno-densytometryczną metodę oznaczania propoksuru (2-isopropoxyphenyl methylcarbamate) w obrożach dla zwierząt. Ustalono warunki ekstrakcji propoksuru do różnych rozpuszczalników stwierdza- jąc, że metanol oraz czterochlorek węgla są najbardziej przydatne do oznaczeń. Wyniki analiz próbek rzeczywistych pozwalają stwierdzić, że opracowane metody mogą być wykorzystane do analitycznej oceny zawartości i tożsamości propoksuru w obrożach dla zwierząt, bowiem w obu przypadkach uzyskano zgodność wyników.