Have you ever wondered why soft gelatin capsules rely on both glycerin and sorbitol?
- It’s all about creating the ideal balance of flexibility and stability for the capsule shell.
- Glycerin, the primary plasticizer, ensures capsules remain flexible and prevents brittleness.
- But on its own, glycerin can’t always deliver the perfect moisture balance for all formulations.
This is where sorbitol comes into the picture as a secondary plasticizer, working hand in hand with glycerin to fine-tune moisture levels. It enhances elasticity without over-softening the shell and plays a key role in maintaining long-term stability, especially in environments with varying humidity.
The ideal ratio?
Typically, 70% Glycerin to 30% Sorbitol strikes the right balance, offering:
- Superior flexibility
- Reduced risk of cracks or leaks
- Stability even under challenging storage conditions
Why is this important?
Because the right balance of plasticizers ensures that capsules aren’t just effective, they’re also durable and market-ready for extended periods. This critical aspect of formulation plays a big role in bioavailability, shelf life, and overall product performance.
Read also: The Basics of Soft Gelatin Capsules
Resource Person: Dr. Atia Iftikhar
