Purpose: To investigate the interaction and compatibility between a soft contact lens (SCL) and an ophthalmic drug.
Methods: Samples were prepared with the nonionic SCL (groups I and II), the anionic SCL (group IV), and the zwitter ionic SCL (group IV). Chlorpheniramine maleate and sodium cromoglycate were used to measure the drug uptake into the SCL.
Results: The results showed the largest drug uptake into the anionic SCL accompanied with dimensional changes and lower drug uptakes into the nonionic and the zwitter ionic SCL with dimensional stability. The cell permeability of the substances when instilled in the eye over the SCL was also measured. The zwitter ionic SCL allowed cell permeability comparable to that by oral administration.
Conclusions: These results indicated the possibility for the zwitter ionic SCL as a lens to be worn concomitantly with ophthalmic drug instillation.