The polymeric hydrogels proved just as effective as pig tissues for testing the mucoadhesive properties of tablets designed to stick to the slippery mucosal linings of the mouth. Dr Vitaliy Khutoryanskiy, from Reading School of Pharmacy, Reading, explained that mucoadhesive polymers are attracting considerable interest as vehicles to prolong the time that tablets are in contact with the mouth’s mucosal lining. But, until now, the only way to test their potential has been to stick them to samples of animal mucosal tissue and measure the amount of force needed to remove them.

‘Glass, polyethylene, polypropylene and polystyrene have all been used as substitutes, but none has the elasticity, moisture content and porosity needed to mimic animal tissue,’ said Khutoryanskiy. ‘The new synthetic hydrogels mimicked the porcine mucosal tissues better than any other material we tested, and could prove a real alternative to using animal material for testing the mucoadhesive properties of future medicines.’

The polymeric hydrogels used by the Reading researchers were synthesized by three-dimensional copolymerization of 2-hydroxyethylmethacrylate (HEMA) with 2-hydroxyethylacrylate (HEA) and were purified by extracting unreacted monomers with deionized water [1]. The ability to mimic animal tissue depended on the HEMA:HEA ratio in the hydrogels; the best results were achieved for samples with intermediate swelling capacity/mechanical characteristics.

References

1 Khutoryanskaya, O.V. et al. (2008) Designing temperature-responsive biocompatible copolymers and hydrogels based on 2-hydroxyethyl(meth)acrylates. Biomacromolecules 9, 3353–3361