Traditional methods to coat solid oral dosage forms mostly use solvents, an approach that suffers from a range of drawbacks including cost, environmental concerns and lengthy processing times. Hot melt coating (HMC) is an innovative and effective alternative that is reliable, cheap and fast, while simultaneously offering an opportunity to better manipulate and control characteristics such as taste, stability and release rate.
Here, we discuss the need for HMC, provide technical details of the process including the excipients involved, explore the relative merits and drawbacks of the technology and touch upon how the process can be scaled up ready for commercial production. In particular, we focus on using HMC to coat user-friendly dosage forms such as orally disintegrating granules (ODGs) and the constituents of traditional dosage forms such as hard gelatine capsules and tablets. In each case, HMC enables the development of medicines with fast or extended release profiles, improved stability and longer product shelf life. In the case of ODGs, palatability and ease of swallowing can be improved resulting in higher compliance.
The article was published in TechnoPharm 4, Nr. 5, pages 258–263, 2014.