The in-vitro release of salbutamol, a bronchodilator, was studied after by complexation with perbutanoyl-β-cyclodextrin (TB-β-CyD).

A prolonged maintenance (at least 24 h) of higher and constant salbutamol levels in plasma was obtained after oral administration of the salbutamol complex in dogs; the area under the plasma salbutamol concentration curve up to 24 h post-administration of TB-β-CyD complex was about 5 times that of salbutamol alone. Furthermore, the plasma level of salbutamol glucuronide, a major metabolite of salbutamol, after the administration of TB-β-CyD complex was significantly lower than that after administration of the drug alone, probably because of the suppression of the metabolism of salbutamol in the gastrointestinal tract by TB-β-CyD complexation.

The present results indicate that TB-β-CyD may be a useful carrier for orally administered water-soluble drugs, especially for drugs which are metabolized extensively in the gastrointestinal tract.