Drugs are administered to the eyes to reduce intraocular pressure for local effects such as migraines, myotia and anesthesia or treatment of glaucoma. The ophthalmic formulation delivers the drug to the eyes or conjunctiva. Drug penetrations into the eyes are not an effective procedure. It is estimated that only one tenth of the dose enters the eye. The formulation includes an aqueous suspension, an aqueous solution, inserts and plaster. To avoid microbial contamination of the eyes, each eye product must be sterile in its final container. Formulated to maintain sterility once the container is opened, the preservative is added to the formulation. The ophthalmic formulation also requires that the buffer capacity, pH, tonicity and viscosity of the formulation be carefully controlled.
