Proton Magnetic Resonance Spectroscopic Determination of Disulfiram: Collaborative Study

1978 ◽  
Vol 61 (1) ◽  
pp. 55-59
Author(s):  
Eric B Sheinin ◽  
Walter R Benson
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Drug Product ◽  
Spectroscopic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Spectroscopic Determination ◽  
Standard Deviations ◽  
Bulk Drug

Abstract A proton magnetic resonance spectroscopic method for determining disulfiram in the bulk drug product and in the formulated material was collaboratively studied. The method depends on the use of chloroform-d as a solvent and hexamethylcyclotrisiloxane as the internal standard. No interference from tablet excipients was observed. The method is rapid and specific. Eighteen laboratories analyzed duplicate samples of a bulk drug product, a 250 mg tablet composite, and a 500 mg tablet composite. The average per cent results and standard deviations were 99.7±1.4, 100.9±2.0, and 99.9±2.2, respectively.

Proton Magnetic Resonance Spectroscopic Method for Determination of Phenylbutazone and Oxyphenbutazone in Tablets

1988 ◽  
Vol 71 (3) ◽  
pp. 525-527
Author(s):  
Sajid Husain ◽  
M Kifayatullah ◽  
R NAGESWARA RAO
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Spectroscopic Method ◽  
Internal Standard ◽  
Aromatic Proton ◽  
British Pharmacopoeia ◽  
Standard Deviations ◽  
Proton Resonances

Abstract A simple, specific, and rapid 'H nuclear magnetic resonance spectroscopic method for the assay of phenylbutazone and oxyphenbutazone is described. Spectra are recorded in CDC13 containing 1,3- dichloro-5-nitrobenzene as an internal standard. The aromatic proton resonances for the standard, at 57.7 and 8.2, are well separated from those of phenylbutazone and oxyphenbutazone, which are in the region of 56.5-7.3 ppm. Average percent recoveries of phenylbutazone and oxyphenbutazone were 98.9 and 98.6 with standard deviations of 0.6 and 0.7, respectively. Commercial formulations were analyzed and the results obtained by the proposed method closely agreed with those found by the British Pharmacopoeia method

Proton Magnetic Resonance Spectroscopic Determination of Bethanechol Chloride in Tablets

1987 ◽  
Vol 70 (3) ◽  
pp. 557-559
Author(s):  
George M Hanna ◽  
Cesar A Lau-Cam1
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Spectroscopic Method ◽  
Proton Magnetic Resonance Spectrum ◽  
Spectroscopic Determination ◽  
Detailed Interpretation ◽  
Bethanechol Chloride

Abstract A simple and reliable proton magnetic resonance spectroscopic method was developed for the assay of bethanechol chloride in tablets. The proposed method entails a minimum of procedural steps and reagents. The recovery of bethanechol chloride from synthetic formulations was 99.9 ± 0.4% (n = 15), CV = 0.4%. Mean assay values for 25 and 10 mg commercial tablets were 100.5% (n = 8) and 99.7% (» = 7) of declared, respectively. A detailed interpretation of the proton magnetic resonance spectrum is also presented.

Determination of Ephedrine, Pseudoephedrine, and Norephedrine in Mixtures (Bulk and Dosage Forms) by Proton Nuclear Magnetic Resonance Spectroscopy

1995 ◽  
Vol 78 (4) ◽  
pp. 946-953 ◽  
Author(s):  
George M Hanna
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Method ◽  
Internal Standard ◽  
Dosage Forms ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
1H Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

Abstract A simple, specific, and accurate 1H nuclear magnetic resonance (NMR) spectroscopic method has been developed for quantitative determination of the Ephedra alkaloids (−)-ephedrine, (+)-pseudoephedrine, and (±)-norephedrine, either singly or in mixtures with each other. Determination of individual alkaloids was carried out in D2O solution, with acetamide as internal standard. Although calculations were based on integrals for the C–CH3 protons, those for the N–CH3 and –CH–O– protons may also be useful, depending on the compound. Determination of diastereomeric cross-contamination of ephedrine and pseudoephedrine—or of the concentrations of these alkaloids in the presence or absence of (±)-norephedrine—was feasible by using the integrals for the –CH–O– protons after addition of a trace of DCI. Mean recoveries for ephedrine and pseudoephedrine from their respective synthetic mixtures with the internal standard (acet- amide) were ≥99.9 ± 0.6% (n = 10) and 99.6 ± 0.8% (n = 10) of the amount added. Recovery for pseudoephedrine from diastereomeric mixtures with ephedrine was >99.4 ± 0.7% (n = 10) of the amount added, with as little as 1.92% still being measurable. Mean recovery of (±)-norephedrine from mixtures with ephedrine and pseudoephedrine was >99.7 ± 2.5% (n = 4) of the amount added, with about 1% still being measurable. Application of the proposed NMR spectroscopic method to commercial dosage forms, including ephedrine sulfate injections and pseudoephedrine hydrochloride tablets, yielded assay results ranging from 97.8 to 100.2% (mean, 99.2%) and from 98.7 to 100.5% (mean, 99.7%) of declared, respectively.

Gas-Liquid Chromatographic Determination of Nicotine Contained on Cambridge Filter Pads: Collaborative Study

1979 ◽  
Vol 62 (2) ◽  
pp. 229-236 ◽  
Author(s):  
John R Wagner ◽  
Neil A Thaggard
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Helium Flow ◽  
Injection Port ◽  
Paired Samples ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract Nicotine was extracted from Cambridge filter pads with 10 mL 2-propanol containing 1 mg anethole/mL as the internal standard. Five standards ranging from 0.25 to 1.25 mg nicotine/ mL were injected into a 6 ft × 1/8 in. column packed with 2% KOH and 10% Carbowax 20M on 45—60 mesh diatomaceous earth to standardize the procedure. The injection port and detector were operated at 200—250°C, the column was operated at 165°C, and the helium flow was adjusted to ca 40 mL/min. Data were taken with systems giving resolutions of 1 count/mv-sec. Results from 16 laboratories gave standard deviations ranging from 0.02 to 0.06 mg nicotine/mL. Suggested improvements were incorporated into a second study, and 13 laboratories analyzed 5 paired samples; standard deviations ranged from 0.02 to 0.03 mg nicotine/mL. The method has been adopted as official first action.

scholarly journals Determination of Retinyl Palmitate (Vitamin A) in Fortified Fluid Milk by Liquid Chromatography: Collaborative Study

2003 ◽  
Vol 86 (2) ◽  
pp. 375-385 ◽  
Author(s):  
Douglas A Hite ◽  
L Angelo ◽  
S Bhandari ◽  
S Bhattacharyya ◽  
E Bonnin ◽  
...  
Keyword(s):  
Vitamin A ◽  
Milk Fat ◽  
Collaborative Study ◽  
Skim Milk ◽  
Internal Standard ◽  
Retinyl Palmitate ◽  
Test Portion ◽  
Standard Deviations ◽  
Fluid Milk

Abstract A liquid chromatographic (LC) method was developed for fast and simple measurement of retinyl palmitate (vitamin A) in fortified milk. Retinyl acetate internal standard was added to a test portion of milk followed by extraction into hexane. The hexane extract was analyzed by LC using a normal-phase silica gel column equilibrated with mobile phase (conditioned hexane–isopropanol, 99.85 + 0.15, v/v) about 1 h before injections. The retinyl palmitate concentration was calculated by using a relative response factor determined with calibration standards. In the collaborative study, 11 laboratories analyzed 13 pairs of fluid milk materials in blind duplicate. Twelve of the materials were composed of skim milk (<0.5% fat), 1% fat milk, 2% fat milk, and 1% fat chocolate milk. Each material was fortified at 3 concentrations of retinyl palmitate of approximately 581 μg/L (1000 IU/qt), 1163 μg/L (2000 IU/qt), and 2236 μg/L (4000 IU/qt). The 13th material, unfortified skim milk, served as a matrix blank. Repeatability standard deviations (RSDr) without outliers ranged from 1.5 to 5.7% and reproducibility standard deviations (RSDR) without outliers ranged from 5.0 to 22.7%. cis-Isomers co-eluted with the predominant trans-retinyl palmitate isomer and were included in the results reported by all the collaborative laboratories. Endogenous long-chain esters from milk fat were also measured with the retinyl palmitate additive. The Study Director recommends that this method for determination of retinyl palmitate in fluid milk by LC be adopted First Action.

Application of ^-Nuclear Magnetic Resonance Spectroscopic Method for Quinidine to Simultaneous Determination of Quinidine and Dihydroquinidine in Quinidine Sulfate Tablets

1988 ◽  
Vol 71 (6) ◽  
pp. 1118-1121
Author(s):  
George M Hanna ◽  
Cesar A Lau-Cam
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Method ◽  
Internal Standard ◽  
Deuterated Chloroform ◽  
Structural Differences ◽  
Commercial Source ◽  
Quinidine Sulfate ◽  
Nuclear Magnetic

Abstract Based on the structural differences between quinidine and dihydroquinidine, a 'H-nuclear magnetic resonance spectroscopic method previously reported for quinidine drug substance was modified and shown to be applicable to the quantitative determination of both compounds in quinidine sulfate tablets. Deuterated chloroform was used as the solvent and hexamethylcyclotrisiloxane served as an internal standard. The average recovery and standard deviation of quinidine sulfate (calculated as the sum of quinidine sulfate plus dihydroquinidine sulfate) from synthetic formulations was 98.94 ± 0.43% (n = 10). Five lots of 200 mg tablets of quinidine sulfate from one commercial source were found to contain from 92.9 to 95.8% quinidine sulfate, and from 1.1 to 7.0% dihydroquinidine sulfate

Gas-Liquid Chromatographic Quantitation of Pheneyclidine.HCl in Powders: Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 560-563
Author(s):  
Charles C Clark
Keyword(s):  
Aqueous Solution ◽  
Collaborative Study ◽  
Internal Standard ◽  
Water Soluble ◽  
Standard Deviations ◽  
Hcl Concentration ◽  
Liquid Chromatographic

Abstract Six laboratories collaboratively studied a method for the quantitative gas-liquid chromatographic (GLC) determination of pheneyclidine. HCl in powders. The pheneyclidine.HCl and other water-soluble compounds are dissolved in dilute HC1. A portion of the aqueous solution is made weakly basic with K2HPO4, and the organic-soluble compounds are extracted in CHCI3 for the GLC determination of the pheneyclidine.HCl. Eicosane (n-C20) is incorporated in the extracting CHC13 as an internal standard. The samples collaboratively studied included samples of known pheneyclidine. HCl concentration and one sample of unknown purity. Recoveries ranged from 92.1 to 104% and per cent standard deviations from 1.05 to 3.39. The method was adopted as official first action.

Liquid Chromatographic Determination and Identification Tests for Dexamethasone in Bulk Drugs and Elixirs: Collaborative Study

1987 ◽  
Vol 70 (6) ◽  
pp. 967-973
Author(s):  
Elaine A Bunch
Keyword(s):  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Dosage Level ◽  
Chromatographic Determination ◽  
Photometric Detection ◽  
Coefficients Of Variation ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract A normal phase liquid chromatographic method for the determination of dexamethasone in bulk drugs and elixirs was collaboratively studied by 6 laboratories. The method uses a silica column, water-modified acetic acid-methanol-methylene chloride mobile phase, cortisone internal standard, and photometric detection at 254 nm. Collaborators were supplied blind duplicate samples of 3 bulk drugs, 2 commercial elixirs, and 1 authentic elixir. Dexamethasone elixir dosage level is 0.5 mg/5 tnL. Mean recovery of dexamethasone from the authentic elixir formulated to contain 0.471 mg/5 mL was 94.5%. (Authentic elixirs were found to stabilize about 6% below the theoretical concentration.) Mean recovery for the bulk drugs was between 97.1 and 100.1%. Mean coefficients of variation for bulk drug and elixir samples were less than 0.8% and 3.6%, respectively. Identification tests for dexamethasone by thin-layer chromatography, infrared spectroscopy, and relative LC retention times, as well as the gas chromatographic determination of alcohol in the elixirs were also collaboratively studied. Mean recovery of alcohol from the synthetic elixir was 98.6%. The mean coefficient of variation for alcohol for all samples analyzed was less than 1.4%. The LC method for dexamethasone in drug substance and elixirs, the identification tests, and the GC method for alcohol in dexamethasone elixirs have been adopted official first action.

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