In vitro-In vivo Relationship and Bioequivalence Prediction for Modified-Release Capsules Based on a PBPK Absorption Model.

A physiologically based pharmacokinetic (PBPK) absorption model was developed in GastroPlus™ based on data on intravenous, immediate-release (IR), and modified-release (MR) drug products. The predictability of the model was evaluated by comparing predicted and observed plasma concentration profiles; average prediction errors (PE) were below 10%. IVIVR was developed using mechanistic deconvolution for a MR drug product to evaluate the in vivo effect of a proposed change in dissolution specification. The predictability of the IVIVR was evaluated and PE were below 10%; however, external validation was not possible due to the lack of data. The developed PBPK absorption model and IVIVR were used to predict plasma concentration profiles and pharmacokinetic (PK) parameters for a hypothetical formulation with 0% of drug dissolved in 2 h in in vitro dissolution test. Both methods predicted the insignificant effect of a change in in vitro dissolution profile on in vivo product performance. The bioequivalence of a hypothetical formulation to the test product was evaluated using virtual clinical trial. The performed analysis supported the proposed change in dissolution specification. A validated PBPK absorption model was proposed as an adequate alternative to IVIVC, when IVIVC could not have been developed according to the guidelines.

Efficacy of Calcipotriol-Betamethasone Ointment in Patients with Mild to Moderate Plaque Psoriasis: Subgroup Analyses.

BACKGROUND: Several factors have been shown to affect psoriasis pathogenesis, clinical presentation and treatment response. OBJECTIVES: The aim of this study was to investigate the potential relationship between patients' baseline characteristics and the efficacy of calcipotriol-betamethasone ointment in patients with mild to moderate plaque psoriasis and to evaluate whether the efficacy is consistent across subgroups. METHOD: Using data from the therapeutic equivalence study on patients with plaque psoriasis, post hoc analyses were performed to evaluate the impact of baseline demographic and disease characteristics, habits and comorbidities on the response to treatment with calcipotriol-betamethasone ointment. RESULTS: Body mass index (BMI) and obesity were each independently associated (univariate analysis, p < 0.05) with reduction in modified Psoriasis Area and Severity Index (mPASI) and PASI75 (≥75% improvement in mPASI from baseline). Increased body weight is more common in patients with late-onset psoriasis. There was a significant trend for lower response rates with increasing BMI (p = 0.007) and obesity (p = 0.003). The odds of achieving PASI75 is 2.3 times lower for obese compared to normal-weight subjects.If patients with obesity or hypertension were treated with calcipotriol-betamethasone, they were still more likely to achieve PASI75 after 4-week treatment compared to vehicle (p < 0.001). CONCLUSION: Increased BMI and obesity present risk factors for reduced treatment effectiveness. Importantly, the efficacy of calcipotriol-betamethasone ointment was consistent in all subgroups.