Wei Zhang

Genentech, USA

Title: Impact of polymer type, ASD loading and polymer-drug ratio on ASD tablet disintegration and drug release

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Biography

Dr. Zhang received his Ph.D. degree in Pharmaceutical Sciences from the University of Wisconsin-Madison in 2016. Since then, Dr. Zhang has been working in the Small Molecule Pharmaceutical Sciences Department at Genentech Inc. Dr. Zhang’s research interest focuses on development of amorphous solid dispersion formulation to deliver poorly water soluble drugs especially with its application in industrial drug development. Dr. Zhang’s work in this area covers the investigation of amorphous solubility enhancement prediction, amorphous formulation stability evaluation, downstream processing of amorphous solid dispersion tablet etc. From his research work, Dr. Zhang has published 19 research papers and given several presentations at conferences and university.

Abstract

This presentation will cover three major topics for amorphous drug product development – (1) theoretical solubility calculation of amorphous drugs; (2) effect of surfactant on the supersaturation maintenance of amorphous formulation and (3) effect of ASD composition on the disintegration and drug release of ASD tablets. At the early stage of drug development, it is critical to understand how much solubility advantage an amorphous form can provide. The first topic will discuss different methods of calculating amorphous drug solubility and the experimental evaluation of these equations. Based on the evaluation, one calculation equation was recommended. After the determination of solubility advantage, composition screening is the second critical step for amorphous formulation development. The second topic will discuss the ASD composition effect on supersaturation maintenance. While extensive studies have been conducted for the effect of polymers, little study has been done on the effect of surfactants. This topic will discuss a systematic study of the effect of surfactants on the crystallization kinetics including nucleation and crystal growth for supersaturated solution. The effect of surfactant-polymer interaction will be also discussed under this topic. For oral administration, the ultimate deliverable is solid dosage form such as a tablet. Owing to great amount of polymers in the ASD composition, the disintegration and drug release usually become an issue for ASD tablets especially when ASD loading increases. The third topic will discuss how polymer type, ASD loading in tablet and polymer-drug ratio affect the disintegration and drug release of ASD tablets. To summarize, the overall goal of this presentation is to provide one of the industrial perspectives for the design and formulation of amorphous drug products based on fundamental understanding of amorphous materials.