Bioavailability of two new formulations of paracetamol, compared with three marketed formulations, in healthy volunteers

Methods Find Exp Clin Pharmacol. 2003 Sep;25(7):531-5. doi: 10.1358/mf.2003.25.7.778092.


The aim of this study was to compare the main pharmacokinetic characteristics of two new paracetamol formulations, powder sachet and tablet, with that of three commercially available paracetamol formulations: two conventional solid tablets and one effervescent tablet. Twelve healthy volunteers participated in an open, single dose (paracetamol 1,000 mg), randomized, five-way, crossover study. Formulations studied included: formulation A: 2 x 500 mg paracetamol tablets (Laboratorios Belmac S.A.); formulation B: 1 x 1,000 mg paracetamol powder sachets (Laboratorios Belmac, S.A.); formulation C: 2 x 500 mg paracetamol film-coated tablets (Panadol, SmithKline Beecham); formulation D: 2 x 500 mg paracetamol tablets (Tylenol, McNeil); and formulation E: 1 x 1,000 mg effervescent paracetamol tablets (Efferalgan, UPSA). The primary variables were area under the plasma concentration time curve extrapolated to infinity (AUC(0-infinity)), maximum plasma concentration (Cmax), and time to maximum plasma concentration (tmax). Mean AUC(0-infinity) ranged from 52.6 (B) to 56.3 microg x h/ml (D); mean Cmax varied between 17.98 (C) and 20.73 microg/ml (E); mean tmax ranged from 0.40 (E) to 0.88 h (C); and median t(1/2) varied between 2.65 (C) and 2.81 h (A). Formulations A, B and E showed significantly shorter tmax than formulation C. The tmax and Cmax values found for formulations A and B were very similar to that found for E, an effervescent tablet formulation. In conclusion, the two new formulations of paracetamol tested in this study were absorbed rapidly after a single oral dose in healthy volunteers, similar to an effervescent paracetamol formulation and significantly faster than two ordinary commercialized paracetamol tablets.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / administration & dosage*
  • Acetaminophen / blood
  • Acetaminophen / pharmacokinetics*
  • Administration, Oral
  • Adult
  • Analgesics, Non-Narcotic / administration & dosage*
  • Analgesics, Non-Narcotic / blood
  • Analgesics, Non-Narcotic / pharmacokinetics*
  • Area Under Curve
  • Biological Availability
  • Cross-Over Studies
  • Female
  • Half-Life
  • Humans
  • Male
  • Powders
  • Tablets


  • Analgesics, Non-Narcotic
  • Powders
  • Tablets
  • Acetaminophen