7.1. Early developments

Microencapsulation is not a new technology. Pioneered by research conducted as far back as the 1930s by the National Cash Register Co. (Dayton, Ohio). Microencapsulation was first commercially applied in 1954 to a product that as revolutionised business forms industry- wide: carbonless copy paper. Another organisation involved in the early research on microencapsulation was the Southwest Research Institute (San Antonio, Texas), which developed a mechanical process to encapsulate liquids or solids using a coating that is solid at room temperature. The National Research Corp. (Boston, Mass.) also conducted extensive research on microencapsulation. In the 1940s, the company had obtained patents on the technology of coating substances with metals in a vacuum-based process. This work served as a springboard for microencapsulation research which began in 1955 on coating abrasive particles with a wetting agent to aid in holding them with adhesives. In the 1950, Dale E. Wurster, then a professor of pharmacy at the University of Wisconsin, devised a process for coating and granulating pharmaceutical tablets and pills. The process, an air suspension technique, involved spraying a coating onto particles that are suspended on a column of air. The principle behind this process is presently applied in many commercially operated fluid bed dryer systems and air suspension systems utilised for micro encapsulation of diverse food ingredients.