Biomaterial Database

Optical purity determination of threo-methylphenidate hydrochloride using a chiral europium nuclear magnetic resonance (NMR) shift reagent. 1990

G M Hanna, and C A Lau-Cam

Food and Drug Administration, Department of Health and Human Services, New York Regional Laboratory, Brooklyn 11232-1593.

A 1H-NMR spectroscopic method for the determination of the optical purity of threo-methylphenidate hydrochloride is presented. Complexation of the free-base form of the substrate with a chiral Eu(III) shift reagent resulted in two distinct enantiomeric ester methyl proton signals of utility for quantitative work. The accuracy of the method was validated by analyzing six synthetic mixtures of various proportions of (+)- and (-)-threo-methylphenidate. In addition to yielding assay results that were in close agreement with the known weights of each enantiomer in the mixture, and a mean recovery of the (-)-threo-enantiomer of better than 99.0%, the proposed method was capable of accurately measuring as little as 2% of one enantiomer in the presence of the other.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D008674	Metals, Rare Earth	A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition, they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.	Rare Earth Metal,Rare Earth Metals,Earth Metal, Rare,Earth Metals, Rare,Metal, Rare Earth
D008774	Methylphenidate	A central nervous system stimulant used most commonly in the treatment of ATTENTION DEFICIT DISORDER in children and for NARCOLEPSY. Its mechanisms appear to be similar to those of DEXTROAMPHETAMINE. The d-isomer of this drug is referred to as DEXMETHYLPHENIDATE HYDROCHLORIDE.	Centedrin,Concerta,Daytrana,Equasym,Metadate,Methylin,Methylphenidate Hydrochloride,Phenidylate,Ritalin,Ritalin-SR,Ritaline,Tsentedrin,Hydrochloride, Methylphenidate,Ritalin SR
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D005063	Europium	An element of the rare earth family of metals. It has the atomic symbol Eu, atomic number 63, and atomic weight 152. Europium is used in the form of its salts as coatings for cathode ray tubes and in the form of its organic derivatives as shift reagents in NMR spectroscopy.
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer