Comparative physicochemical and pharmacokinetic profiles of inhaled beclomethasone dipropionate and budesonide.

The physicochemical and pharmacokinetic characteristics of BDP and budesonide are somewhat different, but the overall result is that both are well suited for use as inhaled corticosteroids. Both BDP and budesonide are metabolized primarily by the liver, with one of the metabolites of BDP, 17-BMP, having greater receptor affinity than either the parent compound or budesonide, which has no active metabolites. BDP has a lower water solubility than either 17-BMP or budesonide, which have similar water solubilities. Budesonide has lower oral bioavailability than BDP; however, it is generally reported to have a longer plasma half-life than either BDP or 17-BMP. The physicochemical and pharmacokinetic profiles of inhaled BDP and budesonide provide both compounds with a favourable ratio of topical to systemic effects and support their well-established role in the treatment of asthma. The device used to deliver an inhaled corticosteroid influences the lung deposition of the drug and selection of the device should be made with an understanding of the particular advantages and disadvantages of the device for each individual patient.