Pharmacological Sciences

Summary

Generally, contact lens products are sterile solutions or suspensions. Formulators for these products must have training in technologies practiced during development of sterile pharmaceutical products, such as injectable and large-volume IV fluids. The products must be effective and compatible with a wide range of lens materials. Components of the formulations should not accumulate in the lens or change the lens properties. They must be preserved adequately and be well tolerated by the sensitive ocular tissues. The products should also be simple to use to assure good compliance on the part of lens wearers. Additionally, they should be developed following the guidelines enumerated in Table 12.

Table 12 Types of Tests and Requirements Proposed by the FDA for Product Development

Chemistry/manufacturing

Solution/container descriptions Solution stability testing Lens group selection for solution testing Toxicology

Solution testing

Acute oral toxicity assessment Acute systemic toxicity assessment Acute ocular irritation and cytotoxicity assessment Sensitization/allergic response assessment Preservative uptake and release test Guinea pig maximization testing Container/accessory testing In vitro testing Systemic toxicity testing Primary ocular irritation testing Microbiology

Sterilization of the solution by the manufacturer Validation of the sterilization cycle USP sterility tests

USP-type preservative effectiveness test USP microbial limits test Shelf life-testing requirements Shelf life sterility

Shelf life preservative effectiveness Extension of shelf life protocol Disinfection of the lens

Chemical disinfection systems Contribution of elements test d-value determinations Multi-item microbial challenge test

Clinical

Patient characteristics

Number of eyes duration and number of investigators Initial patient visit parameters

Abbreviation: USP, United States Pharmacopoeia.