Formulation and evaluation and terbutaline sulphate and beclomethasone dipropionate inhalation mixtures in the rotahaler device

We report the use of low rugosity lactose, product of controlled crystallization of this carrier, in the formulation of terbutaline sulphate and beclomethasone dipropionate dry powder inhalers. The deposition patterns obtained with inhalation mixtures consisting of the modified lactose and each of the micronised drugs terbutaline sulphate and beclomethasone dipropionate have been used to assess the effect of the surface smoothing technique on aerosolised drug delivery. The ROTAHALER device and the Twin Impinger BP were used in the assessment. Drug deposited in the throat, stage 1 and stage 2 of the Twin Impinger BP was determined and used to assess the difference between commercial lactose and the modified lactose prepared. The respirable fraction obtained with inhalation mixtures containing the recrystallized lactose samples was higher compared with inhalation mixtures containing regular lactose BP. Keywords: Rotahaler device, terbutaline sulphate, beclomethasone dipropionate, inhalation mixtures, twin impinger BP, respirable fraction