Liquid Chromatographic Determination of Flucytosine in Capsules

1986 ◽  
Vol 69 (5) ◽  
pp. 825-826
Author(s):  
Donald Shostak ◽  
Clifford Klein

Abstract A liquid chromatographic method has been developed for determination of flucytosine in capsules. Flucytosine and p-aminobenzoic acid, the internal standard, are separated on a C18 reverse phase column using water-methanol-acetic acid mobile phase containing 1-octanesulfonic acid sodium salt. Compounds are detected photometrically at 285 nm. Mean assay results for 250 and 500 mg commercial capsules were 101.5% (n = 5) and 100.2% (n = 5) of declared, respectively. Mean recovery of flucytosine added to commercial capsules was 99.3 %.

1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros

Abstract A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was < 1.5%. The method has been adopted official first action.


1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.


1984 ◽  
Vol 67 (3) ◽  
pp. 497-499
Author(s):  
Stephen C Slahck ◽  
◽  
J B Audino ◽  
O O Bennett ◽  
B D Folsom ◽  
...  

Abstract A liquid chromatographic method for the determination of propoxur in technical and formulated products has been subjected to a collaborative study with 8 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with n-butyrophenone as an internal standard. Collaborators were furnished with samples of technical, 70% wettable powder, 1.5 emulsifiable, and 2% bait. Coefficient of variation values obtained on the 4 samples were 0.34, 0.68, 3.25, and 5.41%, respectively. The method has been adopted official first action.


1982 ◽  
Vol 28 (8) ◽  
pp. 1772-1774 ◽  
Author(s):  
R N Gupta ◽  
P T Smith ◽  
F Eng

Abstract We describe a liquid-chromatographic method involving a new, nonsilica column (XAD-2, Hamilton Co.) for pentobarbital in plasma. Plasma is extracted with chloroform after addition of the internal standard, 5-ethyl-5-p-tolyl-barbituric acid. Acidic drugs are back-extracted into alkali, then chromatographed on the resin-base reversed-phase column. The use of alkaline mobile phase allows enhanced sensitivity and detection of barbiturates at 240 nm. The within-run CV for 10 samples was 1.9%, the between-run CV 1.8%. Ten commonly used barbiturates are separated isocratically in less than 15 min. Other commonly prescribed acidic drugs do not interfere with determination of pentobarbital.


1997 ◽  
Vol 80 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Susan Ting

Abstract A liquid chromatographic method using a reversed- phase C18 column and octanesulfonic acid sodium salt-methanol as the mobile phase was developed for the simultaneous determination of phenobarbi- tal, scopolamine, and hyoscyamine in tablets. The mixture of the 3 drugs was resolved in <8 min. Detector responses were linear for 10 μL injections of the following: scopolamine hydrobromide, 8.25-206.3 μg/mL; hyoscyamine sulfate, 15.01-750.76 μg/mL; and phenobarbital, 250-751 μg/mL. Recoveries from tablets were 100.8% for scopolamine hydrobromide, 100.1% for hyoscyamine sulfate, and 100.3% for phenobarbital. Replicate injections of scopolamine hydrobromide, hyoscyamine sulfate, and phenobarbital gave an overall relative standard deviation of <1.0% (n = 10). The method detected as little as 3.3 ng scopolamine hydrobromide.


1988 ◽  
Vol 71 (1) ◽  
pp. 33-35
Author(s):  
Donald Shostak ◽  
Clifford Klein ◽  
◽  
C Cappon ◽  
N Falcone ◽  
...  

Abstract A liquid chromatographic method for the determination of flucytosine in capsules was collaboratively studied by 7 laboratories. The method uses a C18 reverse phase column, water-methanol-acetic acid mobile phase containing 1-octanesulfonic acid sodium salt, p-aminobenzoic acid as internal standard, and photometric detection at 285 nm. The mean recovery value (±SD) of flucytosine from a synthetic formulation representing capsules was 99.2 ± 1.72% (CV = 1.73%). Composited samples of 250 and 500 mg commercial capsules gave assay values of (mean ± SD) 103.17 ± 2.21 and 99.29 ± 1.29% of declared, respectively. CV values were 2.15 and 1.30%. Reproducibility and repeatability CVs were 2.19 and 1.50%, respectively, for the 250 mg capsules, and 1.34 and 0.63%, respectively, for the 500 mg capsules. The method has been adopted official first action.


1990 ◽  
Vol 73 (6) ◽  
pp. 893-895 ◽  
Author(s):  
Ajay G Patel ◽  
Ramanbhai B Patel ◽  
Mukeshbhai R Patel

Abstract A liquid chromatographic (LC) method has been developed for determination of clobetasone-17-butyrate In ointment using clobetasone propionate as an internal standard. Separation was carried out on a C18 reverse-phase column using water-methanol as a mobile phase. Methylparaben and propylparaben (both sodium salt) used as preservatives did not Interfere with separation. Compounds are detected photometrically at 235 nm. Mean assay results for 0.05% commercial ointments were 100.36% (n = 5). Mean recovery of clobetasone-17-butyrate added to commercial ointment was 99.89%.


1985 ◽  
Vol 68 (3) ◽  
pp. 596-598 ◽  
Author(s):  
Jeffrey A Hurlbut ◽  
Cyril T Nightengale ◽  
Roger G Burkepile

Abstract A liquid chromatographic method was developed for the determination of nicarbazin (4,4'-dinitrocarbanilide.2-hydroxy-4,6-dimethylpyrimidine) in chicken feed. Ground feed was extracted with hot dimethylformamide, filtered, and then cleaned up on an alumina column. The nicarbazin was eluted from the column with ethanol and quantitated using a reverse phase C-18 column, with a methanol-water mobile phase and ultraviolet detection at 344 nm. Recoveries at a typical use level of 100 μg/g feed averaged 98% with a standard deviation of 3%. Samples fortified at levels as low as 0.1 μg/g were analyzed with 92% recovery. The detection limit is 1 ng, and the response is linear between 4 and 1000 ng. Feed additives in combination with nicarbazin do not interfere with recovery.


1982 ◽  
Vol 65 (1) ◽  
pp. 62-65
Author(s):  
Dubravka Matešič

Abstract Supplemental methionine was extracted from a feed sample with O.IM HCI and separated by reverse phase or ion-exchange high pressure liquid chromatography and isocratic elution with KH2PO4 buffer solution as the mobile phase. Methionine was detected at 205 nm. The most reliable results were obtained by using reverse phase chromatography, 0.05M KH2PO4 buffer at pH 2.6 as mobile phase, and tyrosine as internal standard.


1981 ◽  
Vol 64 (3) ◽  
pp. 647-652
Author(s):  
Sandra L Varner ◽  
Charles V Breder

Abstract The determination of residual styrene in polystyrene food packaging polymers by a reverse phase liquid chromatographic method is described. The polymer is dissolved in tetrahydrofuran and then reprecipitated with methanol. The filtered solution is chromatographed by using an aqueous tetrahydrofuran mobile phase, and the styrene is detected and quantitated by ultraviolet at 254 nm. The detection limit for the method is about 0.5 ppm styrene on a solution basis and 20 ppm in the polymer. The average recovery of styrene from spiked polymer (about 50–3700 ppm) is 88%. Apparent residual styrene was determined in several commercial products, including rigid polystyrene cups, flexible plastic containers, and several foam products. The monomer levels ranged from about 60 to 2250 ppm.


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