What preservative is used in Boston Simplus?

• A. Chlorhexidine/PAPB
• B. Polyquad
• C. Polyhexanide
• D. Povidone iodine

Answer: (A)

Preservatives in a lens care product are chosen for how well they keep the solution sterile while staying gentle to lenses and the eye. Boston Simplus uses a two-part preservative system: chlorhexidine together with polyaminopropyl biguanide (PAPB). Chlorhexidine provides strong, broad-spectrum antimicrobial action, and PAPB adds additional antimicrobial activity, helping the solution stay effective over time. This combination is selected because it maintains disinfection effectiveness while being compatible with Boston gas-permeable lenses and minimizing toxicity compared with some older preservatives. Other preservatives like Polyquad or PHMB are used in different solutions, and povidone-iodine is generally an antiseptic used for ocular surface prep rather than a primary preservative in daily MPS products.