Powders

For reasons of stability of the active ingredient in solution, some eye drops may be presented in the form of a sterile powder vial and a separate sterile solvent. The whole must be reconstituted at the time of use. The powder bottle contains the active ingredient(s) and conventional eye drop excipients (isotonizing agents, buffers, preservatives). It may also include excipients such as surfactants to facilitate dissolution and prevent aggregation of solid particles, and freeze-drying aids. The solvent is generally sterile water.

After release into solution, the preparation must comply with Pharmacopoeia requirements for eye drops, and for single-dose preparations with the uniformity tests described in Pharmacopoeia general methods: uniformity of single-dose preparations, uniformity of content and uniformity of mass. By analogy with parenteral preparations, lyophilisates...