Jt. Mcconville et al., Use of a novel modified TSI for the evaluation of controlled-release aerosol formulations. I, DRUG DEV IN, 26(11), 2000, pp. 1191-1198
When considering the development of potential controlled-release pulmonary
drug delivery systems, there is at present no standard method available for
the assessment of in vitro drug release profiles necessary to understand h
ow the drug might release following deposition in the lungs. For this purpo
se, the twin-stage impinger (TSI), apparatus A of the BP, has been redesign
ed and tested. This modified TSI was found capable of discriminating betwee
n drug release rates from conventional and different dry powder formulation
s consisting of model controlled-release excipients, providing information
related to (a) drug diffusion properties of controlled-release dry powder b
lends with different excipient components and (b) the effect of varying dru
g concentration within a given formulation.