ABSTRACT
Asthma is a public health problem for developed countries. It attacks all age groups but often starts in childhood. Theophylline ethanoate of piperazine in a suppository form is one of the treatments of asthmatic children. The pharmacokinetics of theophylline were evaluated in 24 healthy male subjects after administration of theophylline ethanoate of piperazine suppositories (PR) (Minophylline 500 mg. Alexandria Co.) and single injection intravenous (IV) of theophylline ethanoate of piperazine (Minophylline ampoules 500 mg Alexandria Co.). The theophylline serum levels were determined by an ELISA method. Peak theophylline plasma concentration, Cmax, (mean +/- S.D) was 21.5 +/- 2.10 microg/mL & 14 +/- 0.90 microg/mL; AUC(0-t), values were 80.9 and 67. 4 microg x ml x hr for the reference IV preparation and suppositories, respectively. The median peak time, Tmax, was 0.5 hr for theophylline rectal administration. The above mentioned results demonstrate the possibilities of using theophylline (Minophylline Suppositories--500 mg Alexandria Co.) in asthmatic children in rural and desert areas away from health care personnel.
Subject(s)
Theophylline/analogs & derivatives , Administration, Rectal , Adult , Asthma/drug therapy , Biological Availability , Child , Cross-Over Studies , Enzyme-Linked Immunosorbent Assay , Humans , Injections, Intravenous , Male , Suppositories , Theophylline/administration & dosage , Theophylline/pharmacokineticsABSTRACT
An isocratic and simple high-performance liquid chromatographic method was developed for the direct resolution of the clenbuterol enantiomers. The method involved the use of a urea type chiral stationary phase (CSP) made of (S)-indoline-2-carboxylic acid and (R)-1-(alpha-napthyl) ethylamine known as the Chirex 3022 column. The stereochemical separation factor (alpha) obtained was 1.27 and the stereochemical resolution factor (Rs) was 4.2 when using a mobile phase composed of hexane:1,2-dichloroethane:ethanol/trifluoroacetic acid (80:10:10 by vol) at 23 degrees C. The (+)-R enantiomer eluted first, with a capacity factor (k'2) of 2.67 followed by (-)-S enantiomer with a capacity factor (k'1) of 3.38. As standard linear calibration curve was constructed over the range of 10 nmol/mL to 250 nmol/mL with a correlation coefficient of 0.999. The method is specific and sensitive with a lower limit of quantitation of 0.1 nmol. Data demonstrating recovery and precision of the assay are presented and the method has been used to monitor and identify quantitatively the profile of the enantiomers of clenbuterol in biological fluids.
