The safety and tolerability of alkaloids from Alstonia scholaris leaves in healthy Chinese volunteers: a single-centre, randomized, double-blind, placebo-controlled phase I clinical trial

Context Capsule of alkaloids from the leaf of Alstonia scholaris (L.) R.Br. (Apocynaceae) (CALAS) is a new investigational botanical drug (No. 2011L01436) for bronchitis, post-infectious cough and asthma.Objective To observe the clinical safety and tolerability of CALAS.Materials and methods Subjects were assigned to eight cohorts, and each received randomly CALAS or placebo in one of single ascending dose (SAD) of 8, 40, 120, 240, 360, 480, or...