PT  - JOURNAL ARTICLE
AU  - Srinivas, N R
AU  - Quinn, D
AU  - Hubbard, J W
AU  - Midha, K K
TI  - Stereoselective disposition of methylphenidate in children with attention-deficit disorder.
DP  - 1987 Apr 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 300--306
VI  - 241
IP  - 1
4099  - http://jpet.aspetjournals.org/content/241/1/300.short
4100  - http://jpet.aspetjournals.org/content/241/1/300.full
SO  - J Pharmacol Exp Ther1987 Apr 01; 241
AB  - Six boys with attention-deficit disorder were given single doses (5 or 10 mg) of dl-threo-methylphenidate (Ritalin, Ciba-Geigy, Basel, Switzerland). Plasma samples through 8 hr were analyzed by capillary column gas chromatography with electron capture detection. Enantiomers were separated and measured as heptafluorobutyryl-1-prolyl derivatives. The method was sensitive to 0.1 ng of enantiomer per ml of plasma. The plasma levels of d-methylphenidate were at least 5-fold greater than those of the l-enantiomer in the profiles of all six children. Mean areas under the plasma level-time curves were 24.48 +/- 7.62 ng/hr/ml for d-methylphenidate and 3.77 +/- 1.04 ng/hr/ml for l-methylphenidate. There was appreciable intersubject variation in plasma level maxima and times to maximal plasma levels of each enantiomer.