Sensitivity of Different In Vitro Performance Tests and Their In Vivo Relevance for Calcipotriol/Betamethasone Ointment

Purpose We compared results of in vitro performance testing with results of therapeutic equivalence study for calcipotriol/betamethasone ointment, to evaluate their sensitivity and in vivo relevance. Methods Different in vitro methods were used to evaluate drug release and permeation from the test and reference ointment. Moreover, 444 psoriasis patients were randomized in the therapeutic equivalence study and the parameters of efficacy and safety were compared with in vitro results. Results In vitro release and permeation rate of calcipotriol and betamethasone from the test formulation was higher than from the reference product for all methods used ( p ≤ 0.05 for calcipotriol and p