Raft suspensions, used in the treatment of gastroesophageal reflux disease (GERD), contain a gelling agent (sodium alginate, guar gum or pectin), an alkaline bicarbonate and calcium carbonate. Carbopol® polymers (carbomers) have been succesfully used as suspending agents to achieve desired raft characteristics and formulation stability. Carbopol® polymers are crosslinked polyacrylic acid polymers excipients that are efficient rheology modifiers and effective suspending agents.1
Raft forming systems in contact with gastric acid, generate a carbonated gelatinous foam (“raft”).
Benefits of Carbopol® polymers for Suspensions
- Best in class suspending agent: High yield value of Carbopol polymers ensure “permanent” suspensions (no need for shaking) throughout shelf life of product enabling uniform dosage for every administration.
- High efficiency at low inclusion levels (0.2 – 1%) due to their inherently crosslinked structure.
- Formulation flexibility:
- synergies with other ingredients allow for raft tensile strength compliant with pharmacoepial requirements
- different rheological characteristics achieved by variation of inclusion level and degree of neutralization (“no spill” formulations)
- Simplified manufacturing: Low thixotropy allows for ease of mixing, pouring and pumping
- Consistent performance: synthetic polymer with low bioburden and minimal lot-to-lot variability
Patient Centricity in Raft Suspensions with Carbomers
- Established value2: quickly and effectively impeding gastro-oesophageal reflux, for up to 4 hours
- Convenient: Pourable rheology in an easy-to-swallow format
- Palatable: Multiple flavor options without loss of performance
- Unique: Permanent suspension (no need for shaking)
- Reliable: Safe, high-quality ingredients with long history of use
1. Lubrizol webpage Oral-Drug-Delivery--Excipients-for-oral-solids-solutions-and-suspensions.pdf (lubrizol.com)
2. https://www.gaviscon.co.uk/
