# Investigation into the Influence of the Process Parameters on the Stability of a Poly(Vinyl)-Alcohol-Based Coating System

## TL;DR

This study examines how environmental factors affect the stability of a PVA-based tablet coating used since the 1990s.

## Contribution

The paper introduces a multidisciplinary analysis of how UV light, temperature, and humidity impact PVA-based coatings.

## Key findings

- FTIR and NMR showed changes in the coating's chemical structure under artificial aging.
- Rheology and DMTA revealed how titanium dioxide and aluminum hydroxide influence coating stability.
- The study highlights the role of formulation components in coating performance under stress.

## Abstract

Most tablets put on the market are coated with polymers soluble in water. The Opadry II 85 series from Colorcon Inc., is a family of PVA-based products marketed since the 1990s. Despite numerous publications on the properties of PVA, to date, limited work has been undertaken to determine the physico-chemical parameters (i.e., UV light, high temperature, and relative humidity) that could affect the performance of PVA-based coatings. To this end, we performed artificial ageing processes on samples made of Opadry Orange II or of some selected components of this coating and analysed them by means of a multidisciplinary approach, using, for example, FTIR, NMR, rheology, and DMTA measurements. In this way, we analysed the influence of the critical components of the Opadry Orange II formula, such as titanium dioxide and aluminium hydroxide, on the coating characteristics under ageing conditions.