title: Bioequivalence and Pharmacokinetic Evaluation Study of Acetaminophen vs. Acetaminophen Plus Caffeine Tablets in Healthy Mexican Volunteers.
abstract: OBJECTIVE
  The aim of this clinical trial was to establish the bioequivalence of two tablets containing acetaminophen 650 mg (reference) and acetaminophen 650 mg plus caffeine 65 mg (test), administered orally, in fasting conditions in healthy Mexican volunteers.
  
  
  METHODS
  Blood samples were taken from 21 male and five female individuals, during a 24-h period, to characterize the pharmacokinetic profile of acetaminophen. Plasma samples were quantified by ultra-performance liquid chromatography, tandem mass spectrometry. Pharmacokinetic metrics (maximum plasma concentration, area under the curve from time zero to the last sampling time, and area under the curve from time zero to infinity) were used to determine the 90 % confidence interval of the test/reference coefficient.
  
  
  RESULTS
  The geometric mean values for maximum plasma concentration obtained for the reference and test products were 9.46 ± 34.21 and 9.72 ± 32.38 µg/mL, respectively, whereas for the area under the curve from time zero to the last sampling time the values obtained were 34.93 ± 32.58 and 35.89 ± 31.03 µg h/mL for the reference and test formulations, respectively. The 90 % confidence intervals were within the acceptance range (80-125 %).
  
  
  CONCLUSIONS
  The test product was bioequivalent to the reference product. A faster absorption was seen in the test formulation in the Mexican population.
authors.affiliation: Clínica de Enfermedades Crónicas y de Procedimientos Especiales, Fray Bernardino de Sahagún #101, Fraccionamiento Mirador del Punhuato, Morelia, Michoacán, Mexico. nora.nunez@cecype.com.
authors.forename: Nora Angélica Núñez
authors.initials: NA
authors.lastname: Guzmán
authors.affiliation: Clínica de Enfermedades Crónicas y de Procedimientos Especiales, Fray Bernardino de Sahagún #101, Fraccionamiento Mirador del Punhuato, Morelia, Michoacán, Mexico.
authors.forename: Daniel Ruiz
authors.initials: DR
authors.lastname: Molina
authors.affiliation: Clínica de Enfermedades Crónicas y de Procedimientos Especiales, Fray Bernardino de Sahagún #101, Fraccionamiento Mirador del Punhuato, Morelia, Michoacán, Mexico.
authors.forename: Benigno Figueroa
authors.initials: BF
authors.lastname: Núñez
authors.affiliation: Clínica de Enfermedades Crónicas y de Procedimientos Especiales, Fray Bernardino de Sahagún #101, Fraccionamiento Mirador del Punhuato, Morelia, Michoacán, Mexico.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Soto-Sosa
authors.affiliation: Clínica de Enfermedades Crónicas y de Procedimientos Especiales, Fray Bernardino de Sahagún #101, Fraccionamiento Mirador del Punhuato, Morelia, Michoacán, Mexico.
authors.forename: Jorge Eduardo Herrera
authors.initials: JE
authors.lastname: Abarca
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D002110:Caffeine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D013607:Tablets / Q000008:administration & dosage / Q000493:pharmacokinetics; D053719:Tandem Mass Spectrometry; D013810:Therapeutic Equivalency; D055815:Young Adult
chemical_list: D013607:Tablets; D000082:Acetaminophen; D002110:Caffeine