This is a single-center, randomized, cross-over placebo controlled study to evaluate the changes in tear volume by P-321 Ophthalmic Solution and Placebo. The study will enroll subjects with tear deficient dry eye disease to receive sequentially one of two treatment sequences: P-321 Ophthalmic Solution then Placebo or Placebo then P-321. The study will consist of two Phases: In each Phase, subjects will be treated with P-321 Ophthalmic Solution under the same study design.
Approximately twenty-four eligible subjects will complete the study with approximately 8 subjects participating in Phase 1 and the remainder of the 24 subjects participating in the phase 2. Decisions on the dose to be used in Phase 2 will be made based on Phase 1 data.
The study will consist of three study visits: a Screening Visit (Visit 1), and two treatment visits (Visit 2 and Visit 3). The primary and secondary outcome measures will be assessed at each treatment visit. Safety assessments include adverse events (AEs).
