This was a single-center, randomized, double-blind, cross-over, placebo-controlled study. Following screening, each eligible subject was randomized to a dosing sequence. Study subjects received a total of 5 single doses, each separated by a 3- to 14-day washout period. Doses A, B, C, and D were administered in a double-blind fashion, in sequences generated by a 4-period Latin square design. The 4 dosing sequences were: ABCD, BDAC, CADB, and DCBA. Dose E was administered in an open-label fashion as the final dose in each dosing sequence for all subjects.
Subjects reported to the clinic the evening prior to each dose. Protocol assessments were carried out until 24 hours postdose. Pulmonary function testing (via spirometry) was captured at specified timepoints at baseline as well as before and after dosing. Other efficacy and safety outcomes were assessed according to protocol. Blood sampling was performed for assessment of trospium concentrations at specified timepoints.