Eligibility Criteria:
Inclusion Criteria
1. Ability to provide approved written informed consent and comply with study-related procedures/assessments for the duration of the study, age \> 18 years
2. Corrected visual acuity \>20/25 in both eyes
3. IOP \<21 mm Hg, with a difference between eyes of \< 4 mm Hg
4. Ability to tolerate and self-administer vehicle eye drops.
5. Tolerance of a commercially available non-preserved, artificial tear solution
6. Normal slit lamp exam and dilated fundoscopic exam within one week previous to dosing
7. Normal clinical laboratory profiles for complete blood count, serum chemistry and electrolytes, and urinalysis with no clinically significant values
8. Be neither overweight nor underweight for his/her height as per BMI scale (18.5-24.9)
9. Female of childbearing potential:
* Is practicing an acceptable method of birth control for the duration of the study, such as condoms, foams, jellies, diaphragm, IUD, or abstinence; or
* Is postmenopausal for at least 1 year; or
* Is surgically sterile (bilateral tubal ligation, bilateral oophorectomy, or hysterectomy)
Exclusion Criteria
1. Evidence of organ dysfunction or any clinically significant deviation from the normal, in physical or clinical determinations
2. History of serious gastrointestinal, hepatic, renal, cardiovascular, pulmonary, neurological, hematological disease, diabetes, glaucoma, head-injury or coma
3. History of significant recurrent bacterial, viral or fungal infections
4. History of any psychiatric illness, which may impair the ability to provide written informed consent
5. Presence of disease markers of HIV 1 or 2, Hepatitis B or C viruses or syphilis infection
6. Presence of values which are significantly different from normal reference ranges and/or judged clinically significant for haemoglobin, total white blood cells count, differential white blood cell count or platelet count
7. Positive urinary screen testing of drugs of abuse (opiates, cannabinoids, amphetamines, barbiturates, benzodiazepines, cocaine)
8. Presence of values, which are significantly different from normal reference ranges and/or judged clinically significant for serum creatinine, blood urea nitrogen, serum aspartate aminotransferase, serum alanine aminotransferase, serum alkaline phosphatase, serum bilirubin, plasma glucose, serum cholesterol, serum electrolytes (sodium, potassium, chloride, calcium and phosphorus),serum proteins (albumin and globulin) and serum creatinine phosphokinase
9. Clinically abnormal chemical and microscopic examination of urine defined as presence of red blood cells, white blood cells (\>4/High Power Field \[HPF\]), glucose (positive) or protein (positive)
10. Clinically abnormal electrocardiogram
11. Regular smokers, who smoke more than 10 cigarettes daily, or have difficulty abstaining from smoking
12. History of drug dependence or excessive alcohol intake on a habitual basis of more than 2 units of alcoholic beverages per day (1 unit equivalent to half pint of beer or 1 glass of wine or 1 measure of spirit) or have difficulty in abstaining from drinking
13. Subjects who, through completion of this study, would have donated and/or lost more than 400 mL of blood in past 2 months
14. History of ocular surgery, trauma, or chronic ocular disease
15. Current use of contact lenses or discontinuation of contact lens use within 2 weeks of the first dosing day
16. Any ocular abnormalities or ocular symptoms
17. Use of ocular agents (including eye drops) within the past 2 months or anticipated use of ocular agents during the study period
18. Systemic corticosteroid use within the past 6 months
19. History or evidence of ocular infection, inflammation, blepharitis, or conjunctivitis with 2 months; history of herpes simplex keratitis
20. Presence of a non-healing wound, ulcer, fracture, or any medical condition associated with bleeding.
21. Use of antimitotic or antimetabolite therapy within 2 months of enrollment.
22. Women who are pregnant or breastfeeding, or nonsterile or premenopausal women who refuse to use any form of contraception during and for at least 2 weeks following the final dose of study drug.
23. Enrollment in another investigational drug or device study within 2 months of study entry.
24. Known intolerance or hypersensitivity to any components/excipients in the study drug formulation.
25. Planned use during the study of any ocular or systemic medication, with the exception of oral contraceptives and short-term use of over-the-counter analgesics.