Pharmacokinetics and absolute bioavailability of salbutamol in healthy adult volunteers

Abstract

Salbutamol was administered to sixteen healthy male volunteers intravenously and by mouth in liquid, tablet, and capsule form using a Latin-Squares design. Pharmacokinetic parameters from intravenous data were similar to previously reported values obtained with oral administration, with a mean terminal half-life of 3.8 h and a mean clearance of 439 ml X min-1 X 1.73 m-2. Peak plasma concentrations of 10-20 ng X ml-1 were obtained 1-3 h following oral administration. The absolute bioavailability of each of the oral preparations was 44%. While statistically significant differences in lag time and time to peak concentration were noted among the various oral preparations, the drug is rapidly absorbed in all three dosage forms and the observed differences are unlikely to be of clinical significance.

Systemic beta‐adrenoceptor responses to salbutamol given by metered‐ dose inhaler alone and with pear shaped spacer attachment: comparison of electrocardiographic, hypokalaemic and haemodynamic effects.

“…Systemic absorption of inhaled salbutamol may occur following deposition in the lungs and oropharynx, and also from the gut after swallowing. Direct systemic absorption from the buccal mucosa should avoid first-pass metabolism by sulphate conjugation (Walker et al, 1972;Morgan et al, 1986;Goldstein et al, 1987). Kung et al (1987) showed that mouth washing has no effect on systemic ,B-adrenoceptor responses to salbutamol 1 mg given by MDI.…”

Design and Evaluation of an Oral Floating Matrix Tablet of Salbutamol Sulphate

“…A GDDS formulation of the drug may be advantageous over the conventional oral dosage form and inhaler due to its ability to maintain prolonged therapeutic concentrations in systemic circulation [3,4]. Consequently, an attempt was made in the present work to develop a gastroretentive drug delivery system of salbutamol sulphate with a view to increasing the bioavailability of salbutamol sulphate.…”

Influence of route of administration and dosage form in the pharmacokinetics and bioavailability of salbutamol

“…This evolution has two phases: the first one, with a fast decrease of the plasma levels, is followed by a second phase in which the decrease is slower, reaching a value of 0.7 ug/ml after 6 h of administration. Other researchers have also observed this behaviour after intravenous drug administration in humans (18) and rabbits (19). Table I daily and shows equal bioavailability becomes a useful alternative.…”

“…The changes in the salbutamol plasma concentration as a function of time showed only two phases in all the formulations studied. This change in the drug kinetic behaviour depending on the route of administration and the different dosage forms has also been observed in rabbits (19) and in humans (18). This could be due to the fact that the absorption rate of the drug to the systemic circulation has a tendency to equal the return rate of the drug to the tissues throughout which it is distributed (20).…”