The Phase III main study is a randomized, controlled, multicenter, double blind, trial to evaluate the efficacy and safety of TP-03 (lotilaner ophthalmic solution, 0.25%), for the treatment of Demodex blepharitis in Chinese patients. The PK sub-study is a single-arm, open-label trial to evaluate systemic TP-03 in whole blood following topical ocular administration

The main study is designed to demonstrate the superiority of TP-03 compared to vehicle for the treatment of Demodex blepharitis in Chinese patients. The vehicle of TP-03 was selected as the control since there are no approved pharmaceutical treatments for Demodex blepharitis. The vehicle as the control will provide evidence that the active ingredient is responsible for the response, not the vehicle alone.

A pharmacokinetics (PK) sub-study is included in the overall study design to evaluate systemic PK parameters of TP-03 in Chinese participants with Demodex blepharitis. The PK sub-study sites are separate from those of the Phase III study as described above.

Inclusion Criteria:

1. Male or female, aged ≥ 18 years of age.
2. Be willing to sign the informed consent and deemed capable of complying with the requirements of the study protocol.
3. Has blepharitis
4. Stated willingness to comply with all study procedures and availability for the duration of the study.

Exclusion Criteria:

1. Have used lid hygiene products (e.g., lid scrubs) within 14 days of Screening or unwilling to forego the use of lid hygiene products during the study.
2. Have initiated treatment with an ocular topical prostaglandin analogue within 30 days of Screening or have any plans to change or discontinue treatment during the study
3. Pregnancy or lactation.
4. Any intraocular surgery (including ocular surface surgery, cataract surgery and intravitreal injection) or periocular surgery within 60 days prior to randomization, or any planned ocular surgical procedure during the study period
5. Have any unstable or uncontrolled, cardiac, pulmonary, renal, oncological, neurological, metabolic or other systemic condition that, in the opinion of the investigator, would possibly require the participant to seek emergent medical treatment during the course of this study. This includes, but is not limited to, unstable or uncontrolled cardiac arrhythmias, hypertension, coagulopathies, renal failure or advanced diabetes mellitus.