Hermes Pharma has introduced the commercial implementation of hot melt coating (HMC) in its production facility. The implementation of this technology is the result of a research project aimed at developing new pharmaceutical formulations that are stable, effective and user-friendly.

Acetylcysteine (NAC), a thermosensitive mucolytic compound exhibiting an unpleasant sour and metallic taste, was selected as the model active pharmaceutical ingredient (API) for this research project. The dosage form designated was orally disintegrating granules (ODGs), which consist of small granules that are applied directly into the mouth. ODGs do not require any water and are easy to swallow, even for people with difficulties swallowing tablets. As they do not have to be swallowed whole and spend more time in the mouth than conventional tablets, they are more thoroughly tasted, making taste-masking crucially important.

Hermes Pharma deployed HMC to mask the sour and metallic taste of NAC, as well as its sulfuric smell, which are specific to this API. It also achieved a stable, immediate release profile and unaltered polymorphic form of the coating during storage.

HMC was originally developed in the food industry. Among other purposes, it has been used to coat seasoning mixes in convenience food in order to minimize their hygroscopicity and thus volatilization of the flavor during the logistic chain and prior to consumption. Flavor is only released upon heating, but not beforehand, improving taste, smell and quality of ready-made meals. HMC is a solvent-free coating technology that offers very short processing times—depending on the API, coating thickness and scale—and lower costs. The company says it is also more eco-friendly compared to conventional coating methods. HMC involves covering the API solid core with a molten coating material at a carefully controlled temperature. This then solidifies to create a homogenous coating.

HMC is now a proven technology to mask the unpleasant taste and smell, which patients often experience when pharmaceuticals dissolve in the mouth. The technology has been up-scaled from laboratory to production, meeting the strict standards for pharmaceutical production (GMP), and can be transferred to other APIs. The coated API can be blended with excipients and flavors, as well as other APIs for tailor-made products to suit customer requirements and deliver further medical benefits. HMC technology could also be applied to other dosage forms, for example Orally Disintegrating Tablets (ODTs) and Multiple Unit Pellet System (MUPS). Two related patents have been successfully filed.

“We believe that our scientific know-how has led us to prove our technological and production leadership, resulting in being the first company to make HMC commercially available for the pharmaceutical industry,” said Detlev Haack, director research and development, Hermes Pharma. “Our industrial customers will benefit from products that are truly user-friendly and deliver real value to patients and consumers.”