Sustainable Shell Formulations as Alternative to the Conventional Soft Gelatin Capsules in Pharmaceutical and Nutraceutical Applications. A Review.

Abstract Gelatin is the traditional gelling agent used to produce softgels. In recent years, different products have progressively emerged on the market based on other alternative polymers such as starch, carrageenan and pectin. Its use, alone or in combination with other gelling agents, conditions the softgel production and modifies the properties of shell cover material, and therefore, the softgel capsules. In addition, the use of new alternative materials such as alginate, pullulan, cellulose and its derivates, PVA, chitosan, gellan gum and agar have been explored and are becoming more important. Their market inclusion has not only led to improvements in terms of compatibility, manufacture, stability, drug release control, cost and sustainability; but also, has enabled to extend the softgel portfolio offering to the consumers friendlier products with vegetal origin. This review provides an updated overview on the alternative options to traditional gelatin shell cover for pharmaceutical and nutraceutical products. Additionally, it evaluates the impact of this change on the shell material behavior over the production and stability of these pharmaceutical forms. This will help to select the best gelling agent, alone or in combination, depending on the defined specification during the design and development phase of the softgel product.