Quantitative Determination of Chlorpromazine. HC1 in Tablets, Spansules, Injectables, and Bulk Chemical by Nuclear Magnetic Resonance Spectroscopy

Abstract A nuclear magnetic resonance (NMR) procedure is described for the quantitative analysis of chlorpromazine. HC1 in bulk chemical as well as in final dosage forms—tablets, spansules, and injectables. The method is based on measurement of a characteristic signal of chlorpromazine relative to an internal standard. Three different internal standards are specified: Cyclohexane was selected because of the convenience and rapidity with which samples could be prepared for assay. Piperonal was used to verify the method and to show that precision and accuracy were not affected by the volatility of the cyclohexane. Tetramethylammonium bromide was used as an internal standard for Thorazine injectable. No interferences were found from stearates and other tablet excipients. The NMR procedure provides a simple, direct, and specific assay with a precision of ± 1–2%.

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

Journal of AOAC International ◽

10.1093/jaoac/78.4.946 ◽

1995 ◽

Vol 78 (4) ◽

pp. 946-953 ◽

Cited By ~ 11

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.

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Quantitative Analysis of Flavonoids in Glycyrrhiza uralensis Fisch by 1H-qNMR

Journal of Analytical Methods in Chemistry ◽

10.1155/2021/6655572 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Ping Yu ◽

Qian Li ◽

Yanmei Feng ◽

Yuying Chen ◽

Sinan Ma ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Pulse Sequence ◽

Quantitative Characteristic ◽

Internal Standard ◽

Proton Nuclear Magnetic Resonance ◽

Experimental Result ◽

Resonance Spectroscopy ◽

Nuclear Magnetic

Objective. To establish a method for simultaneous determination of liquiritin, liquiritigenin, and isoliquiritinin glycyrrhizin using hydrogen nuclear magnetic resonance quantitative technology (1H-qNMR). Methodology. Deuterated dimethyl sulfoxide was used as the solvent, and dichloromethane was used as the internal standard. The probe temperature was 298.0 K, the pulse sequence was Zg30, the number of scans was 16, and relaxation delay (D1) was 10 s. Quantitative characteristic signal peaks were δ 4.891∼4.878 ppm, δ 8.187∼8.172 ppm, and δ 6.790∼6.776 ppm for liquiritin, isoliquiritin, and liquiritigenin, respectively. Results. The experimental result showed that the content of flavonoids in Licorice, from Chifeng, Inner Mongolia, was the highest. Conclusion. In this study, a new method for determination of three flavonoids in Licorice using 1H-qNMR was established. This experimental method has the advantages of accuracy, efficiency, and economy. It lays a foundation for the study on the determination of flavonoids content in licorice by proton nuclear magnetic resonance spectroscopy.

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