Erratum: Mangas-Sanjuán, V.; et al. Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence. 2019, , 503.

The authors wish to make the following corrections to this paper [...

Statistical Methods for Quality Equivalence of Topical Products. 0.5 mg/g Betamethasone Ointment as a Case-Study.

This study examines the statistical implications, and their possible implementation, of the "Draft guideline on quality and equivalence of topical products" issued by the European Medicines Agency in 2018, with particular focus on the section devoted to quality equivalence of physical properties. A new confidence interval to conduct the quality equivalence test and a way to cope with the multiplicity of quality parameters are presented and discussed. As an example, the results and the statistical analysis of a study on betamethasone 0.

Relationship between rheological properties, in vitro release and in vivo equivalency of topical formulations of diclofenac.

Determination of bioequivalence remains a challenge in generic topical drug development. To support pharmacokinetic studies, strategies to demonstrate microstructure sameness of the products being compared include in vitro evaluations, such as the comparison of rheological properties, droplet size and in vitro release rates. Nevertheless, defining the appropriate acceptance range to consider equivalence between test and reference formulation is complex.

Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence.

Demonstration of similar microstructure is essential for demonstrating the equivalence of generic topical products since the microstructure of semisolids may affect the drug release. The objective of this study was to compare the microstructure-defining physical parameters of different batches of a reference ointment containing calcipotriol and betamethasone (Daivobet 50 µg/0.5 mg/g) in order to define the acceptance range that allows concluding equivalence between these batches.