It is estimated that several hundred tons of film residue is generated annually during the manufacturing process of the soft capsules used in pharmaceutical products. The coating-waste material generally contains few impurities, meaning that it is reasonable to expect that it can be recycled as plastic. However, as the main ingredient, gelatin, lacks the thermal plasticity necessary for manufacturing plastic products, recycling proved difficult.
A research group led by Professor Hiroshi Uyama of the Graduate School of Engineering at Osaka University and a health supplement and pharmaceutical manufacturer API (Gifu City) successfully collaborated to develop high-performance biodegradable plastic using coating-waste material. The coating of soft capsules contains glycerin, which plasticizes gelatin and plays an important role in the properties of the coating. Uyama and his research group focused on this property to create a gelatin-glycerin mixture from the coating-waste material, which they treated with heat to eliminate moisture and thereby thermoplasticized the waste material. Heat deformation enables the application of various molding techniques in manufacturing products.
Furthermore, a high-performance biodegradable plastic prototype was developed by blending thermoplastic gelatin with biodegradable plastics such as polylactic acid. It is expected that the formation of biofilms on plastics containing gelatin further improves biodegradability.
This result is expected to not only contribute to resource circulation and marine litter reduction but also be the first step in responding to social demands for active waste recycling. The research group plans to develop molding technology and manufacture prototypes through industry-academia collaboration.
High-performance biodegradable plastic containing soft capsule-coating waste material.