Compared to gelatin, plant-based alternatives such as seaweed-derived carrageenan or modified starches are more stable at higher temperatures, provide excellent product flexibility, and requires minimum capital investment
Since decades the pharma industry has implemented traditional capsule technology using animal-based gelatin. With the novel innovations, many pharma manufacturers and brand owners are now planning for a plant-based alternative to gelatine.
Various dietary supplements are manufactured as Soft capsules which are easy to swallow, help mask unpleasant odors and tastes, and provide quick delivery of active ingredients. They also enable the consumption of a wide variety of product differentiation, from essential fatty acids to vitamins and minerals, to botanical supplements and probiotics.
Manufacturers looking for a vegan-friendly solution to soft capsule shells have several options, ranging from a variety of seaweed-based alternatives to modified starch. Manufacturers are now looking towards incorporating vegetarian solutions into their own formulations.
Animal-based gelatin, the most traditional soft-capsule shell material, is typically sourced from bovine, porcine, or piscine skin and/or bone, and is available in a variety of gel strengths. It forms a relatively low-viscosity gel that is molten at around 60°C with an acidic pH. Gelatin capsules are thermally sealed and, when wet, have a very high seal strength. However, under warm conditions (~30°C), the capsules can become tacky and fuse together; if left in excessively hot conditions (i.e. 40°C or greater), the capsules can melt completely within a few hours. The gelatin shell can also undergo interactions and crosslinking with the fill material, leading to discoloration or brittleness.
Plant-based soft capsules made with modified starch or seaweed-derived carrageenan, provide consumers with robust and stable soft capsules that satisfy vegetarian, vegan, non-GMO, Kosher and Halal diets.
Seaweed-derived Carrageenan
Carrageenan, a naturally occurring polysaccharide extracted from red seaweed with a high molecular weight (200k-800k Da), provides an excellent vegetarian alternative for soft capsule shells. When manufacturing carrageenan soft capsules, a relatively high-viscosity gel is formed at around 85°C with a neutral pH. The wet seals of these capsules are initially weaker than gelatin capsules; however, after drying, they become strong and thermally stable at elevated temperatures without fusing or melting.
There are a variety of carrageenan types, and each one uniquely impacts capsule shell properties. The two most common types for soft-shell capsules are Kappa and Iota. Kappa carrageenan forms strong and rigid gels, while Iota carrageenan forms rather soft, weak gels. A combination of the two, Kappa 2, has become a popular solution for improving soft capsule shell properties, as it yields superior soft capsule qualities and encapsulation efficiency.
Carrageenan has a long track record as a safe ingredient in food, dietary supplements and pharmaceutical products. However, it’s sometimes erroneously confused with poligeenan, which is an unnatural, low molecular weight (<20k Da) polysaccharide that cannot be produced biologically in the human body. Poligeenan is synthesised in the laboratory by subjecting carrageenan to extremely acidic conditions (0.9-1.3) at elevated temperatures (>80°C) for several hours. It is not authorized for use in any food application.
Modified Starch
Another gelatin-alternative for vegetarian soft capsules is modified starch. Like carrageenan, starch is a naturally occurring polysaccharide extracted from plants such as corn, pea or tapioca. To form soft capsules of acceptable quality, starch is typically mixed with a certain amount of another gelation aid such as carrageenan, forming a high-viscosity gel that is molten (~90°C). However, the wet seals of those starch soft capsules tend to be relatively weak, as the capsules are not thermally sealed. Starch capsule shells are also not as elastic as gelatin or carrageenan, so they are limited to smaller capsule shapes to limit the level of stress on the capsule seals.
Compared to gelatin, plant-based solutions such as carrageenan or modified starches require higher temperatures to mix, transfer and encapsulate. Manufacturers can typically incorporate carrageenan or starch soft capsules into their existing gelatin operations with minimum capital investment by simply adding heat and temperature control systems to existing gelatin equipment. Once installed, the encapsulation process can easily switch between gelatin and non-animal capsule production as needs dictate, providing excellent product flexibility and allowing manufacturers to stay agile in this increasingly competitive market.
Source: Vitafood Insights
