Gelatin is a protein material produced by hydrolysis of collagen from animal bones and connective tissues. Gelatin has served as an encapsulating material, a coating for pills, an emulsifying agent, a coating for photographic materials, a bacterial culture medium, a component of printers' rollers and hectograph plates, an ingredient of popular desserts, and for many other widely varied uses.
One common use for gelatin is in the manufacture of soft gel capsules for the delivery of active ingredients. Although gelatin is generally strong and tough, its extensibility and flexibility are generally low. In addition, since gelatin is derived from animal sources, there are often inconsistencies in product quality from batch to batch. The physical and chemical properties of gelatin are a function of the source of the collagen, method of manufacturing, conditions during extraction and concentration, thermal history, pH and the chemical nature of impurities and additives. Moreover, during storage, gelatin often undergoes a crosslinking reaction which in turn changes the dissolution character and the drug bio-availability characteristics. This shortens the useful life of the gelatin. Thus, mechanical failures of gelatin soft gel capsules are often encountered. Additionally, the use of animal derived materials, such as gelatin, has come under regulatory review due to concerns regarding the transmission of animal based illness.
Accordingly, new materials are desired which can function as replacements for gelatin, particularly gelatin based films useful for manufacturing soft gel capsules and the like.