Our Answer to Evolving Markets
As science advances and the markets for healthcare and nutritional supplementation continue to evolve, so too does the need for reliable delivery systems. Capsules require an improved stability, because on the one hand, regulatory requirements are becoming stricter, and on the other, there are a growing number of reactive ingredients, such as plant extracts, that increase the likelihood of crosslinking causing solubility problems. High temperatures and humidity during transportation and storage can also create issues with capsule solubility, meaning finished products take longer to dissolve in the gastrointestinal tract, with a knock-on effect on efficacy.
Protect Your Products
GELITA’s RXL® Portfolio helps manufacturers produce softgel capsules with enhanced stability and shelf-life. RXL® stands for Reduced Cross (X)-Linking. RXL® gelatin essentially protects itself against cross-linking, resulting in more stable capsules and a more reliable release of fills. Find out more about how RXL® can improve your capsule stability.
What is Crosslinking?
Crosslinking is a process in which new bonds form between separate molecules, with at least one being a gelatin polymer chain. This creates a network of interconnected chains or molecules. In capsule production, crosslinking is undesirable because it can gradually alter the capsule's properties over time, particularly its fill release profile.
There are two types of crosslinking:
- Self-crosslinking where the gelatin in the capsule shell reacts with itself
- Intra-crosslinking where the gelatin in the shell interacts with ingredients inside the capsule.
Self-crosslinking can have various consequences that affect product quality, efficacy and performance. The capsule shell can become hard and brittle and can even crack. Chemical structures likely to incite intra crosslinking activity include aldehydes, ketones, polyphenols, phenols and peroxide intermediates. These substances are often found in fruit and herbal extracts. For example, ketones are contained in essential oils such as peppermint oil.
Intra-crosslinking can also cause the formation of a water-insoluble membrane, known as a pellicle, which can lead to unreliable dissolution and thus hinder the release of the fill.
