title: Comparative bioavailability studies of citric acid and malonic acid based aspirin effervescent tablets.
abstract: OBJECTIVE
  The present investigation is aimed at comparing the pharmacokinetic profile (Bioavailability) of aspirin in tablet formulations, which were prepared by using different effervescent excipients such as citric acid and malonic acid.
  
  
  METHODS
  The relative bioavailability and pharmacokinetics of citric acid based aspirin effervescent tablet (Product A) and malonic acid based aspirin effervescent tablet (Product B) formulations were evaluated for an in-vitro dissolution study and in-vivo bioavailability study, in 10 normal healthy rabbits. The study utilized a randomized, crossover design with a one-week washout period between doses. Blood samples were collected at 0, 1, 2, 4, 6, 8, 12 and 24 hours following a 100 mg/kg dose. Plasma samples were assayed by High Performance Liquid Chromatography. T(max), C(max), AUC(0-24), AUC(0- ∞,) MRT, K(a,) and relative bioavailability were estimated using the traditional pharmacokinetic methods and were compared by using the paired t-test.
  
  
  RESULTS
  In the present study, Products A and B showed their T(max), C(max), AUC(0-24), AUC(0- ∞,) MRT, and K(a) values as 2.5 h, 2589 ± 54.79 ng/ml, 9623 ± 112.87 ng.h/ml, 9586 ± 126.22 ng.h/ml, 3.6 ± 0.10 h, and 0.3698 ± 0.003 h (-1) for Product A and 3.0 h, 2054 ± 55.79 ng/ml, 9637 ± 132.87 ng.h/ml, 9870 ± 129.22 ng.h/ml, 4.76 ± 0.10 h, and 0.3812 ± 0.002 h (-1) for Product B, respectively.
  
  
  CONCLUSIONS
  The results of the paired t-test of pharmacokinetics data showed that there was no significant difference between Products A and B. From both the in vitro dissolution studies and in vivo bioavailability studies it was concluded that products A and B had similar bioavailability.
authors.affiliation: Department of Phramaceutical Technology, Noida Institute of Engg. and Technology, Greater Noida, India.
authors.forename: Anju
authors.initials: A
authors.lastname: Gauniya
authors.forename: Sanjita
authors.initials: S
authors.lastname: Das
authors.forename: Subrata
authors.initials: S
authors.lastname: Mallick
authors.forename: S P
authors.initials: SP
authors.lastname: Basu