title: Relative bioavailability of rapidly dispersing, plain, and microencapsuled acetylsalicylic acid tablets after single dose administration.
abstract: Extent and rate of absorption of acetylsalicylic acid (ASA) from rapidly dispersing (Acesal Extra) and plain tablets (Acesal) relative to reference 1 (plain tablets, Aspirin) and from microcapsuled tablets (Micristin) relative to comparable listed tablets (reference 2, Colfarit) were assessed in 2 single-dose (0.5 g ASA), open, randomized, crossover studies with intervals of 14 days between 2 periods. Both studies were performed in 24 male and female healthy volunteers each (age 18-32 years, body weight 48-90 kg, body height 161-190 cm). ASA and its metabolite salicylic acid (SA) were measured with an HPLC method validated for ASA between 0.2 and 20 microg/ml and for SA between 0.4 and 40 microg/ml. The test tablets were considered bioequivalent with reference in extent of absorption if the 90% confidence limits of the AUC0 to infinity ratio were within the range of 0.80-1.25, and in rate of absorption if the confidence limits of the Cmax/AUC0 to infinity ratios were within 0.70-1.43.
  
  
  RESULTS
  Geometric means and 90% confidence limits for the test/reference ratios of the comparisons Acesal vs reference 1, Acesal Extra vs reference 1 and Micristin vs reference 2 were 1.05 (0.97-1.13), 1.13 (1.05-1.22), 1.02 (0.92-1.14) for ASA AUC0 to infinity and 1.02 (0.96-1.07), 1.05 (0.99-1.11), 0.98 (0.91-1.04) for SA AUC0 to infinity, respectively. The results for Cmax/AUC of ASA were 1.16 (1.00-1.34), 1.72 (1.49-1.99), 0.83 (0.73-0.94) and of SA 1.02 (0.98-1.07), 1.07 (1.02-1.12), 0.93 (0.88-0.97).
  
  
  CONCLUSIONS
  Acesal and Micristin were bioequivalent with the respective references in both extent and rate of absorption. Acesal Extra and reference 1 were bioequivalent with regard to extent only. Acesal Extra was absorbed faster.
authors.affiliation: Department of Pharmacology, Ernst Moritz Arndt University, Medical Faculty, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Siegmund
authors.forename: C
authors.initials: C
authors.lastname: Hoffmann
authors.forename: M
authors.initials: M
authors.lastname: Zschiesche
authors.forename: V W
authors.initials: VW
authors.lastname: Steinijans
authors.forename: R
authors.initials: R
authors.lastname: Sauter
authors.forename: W D
authors.initials: WD
authors.lastname: Krüger
authors.forename: F
authors.initials: F
authors.lastname: Diedrich
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001241:Aspirin / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D018592:Cross-Over Studies; D004304:Dosage Forms; D004337:Drug Carriers; D004339:Drug Compounding; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D012016:Reference Values; D013810:Therapeutic Equivalency
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004304:Dosage Forms; D004337:Drug Carriers; D001241:Aspirin