This study is a prospective Phase 2, drug controlled, open-label study to evaluate the safety and efficacy of Pure Green sublingual tablets for the treatment of pain associated with osteoarthritis of the knee.

Inclusion Criteria:

1. Subject is at least 21 years of age;
2. Subject has a diagnosis of a pain related to osteoarthritis of the knee as determined by the subject's primary care physician or related health care provider.
3. Subject has a mean pain scale score of ≥ 4 recorded in the 7 days prior to enrollment.
4. If female, the subject is postmenopausal (> 1 year), surgically sterile (> 3 months), had a hysterectomy, or is currently using 2 effective forms of birth control.
5. Subject has not taken marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD for at least 14 days prior to this study, and promises to not take marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD while participating in this study.
6. Subject has not taken any pain medication, including NSAIDs, for at least 2 days before taking the first dose of study drug.
7. Subject is willing to provide his/her written informed consent to participate in the study as stated in the informed consent document.
8. Subject is willing to use an electronic diary to enter a pain scale score up to four times a day for 28 days.

Exclusion Criteria

1. Subject is pregnant or lactating;
2. Subject has an allergy to cannabis, the Cannabaceae plant family (e.g., hemp, hops), palmitoylethanolamide, or terpenes;
3. Subject has a known allergy to active or inert ingredients of PG-OA-10:10-2020-B tablets;
4. Subject is taking a concomitant medication or treatment that would complicate use or interpretation of the study drug's effects (examples include: Cannabis or any cannabinoid products; Any drug or herbal product that influences the endocannabinoid system (ECS));
5. Subject is taking marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD for at least 14 days prior to this study, and does not promise that they will not take marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD while participating in this study;
6. Subject is currently being treated with antibiotics for sinus, throat, or lung infections;
7. Subject has shortness of breath associated with allergies;
8. Subject has uncontrolled asthma;
9. Subject has a fever and/or productive cough;
10. Subject has unstable angina, uncontrolled hypertension;
11. Subject currently or has a history of congestive heart failure;
12. Subject has any other unstable medical condition;
13. Subject has a personal or family history of schizophrenia;
14. Subject has a personal history or currently has suicidal ideation or attempted suicide;
15. Subject has a major neurological disorder, such as dementia, Parkinson's disease, cognitive impairment, epilepsy, history of traumatic brain injury/head injury, and seizures.
16. Subject has taken pain medicine of any kind throughout the screening period, or has taken acetaminophen within 2 days of taking the first dose of study drug.
17. Subject has an allergy to, or has an intolerance to, acetaminophen.
18. Subject is currently taking any form of opioids.
19. Subject has a history of alcohol or substance abuse
20. Subject has clinically significant illness, including cardiovascular disorders.
21. Subject has any condition in which the investigator believes will confound the data of the study or could put the subject at risk of harm.
22. Subject does not have access to a smart phone or does not know how to use a smart phone application.