A Study to Evaluate Efficacy and Safety of MELT-300 for Procedural Sedation in Subjects Undergoing Cataract Extraction With Lens Replacement (CELR)

Inclusion Criteria: Participants must meet all of the following in order to be enrolled into the study: 1. Males and females ≥ 18 years of age 2. Are to undergo unilateral primary CELR under topical anesthesia, with a phacoemulsification device and insertion of an intraocular lens (no restrictions on lens type) 3. For women of childbearing potential (WOCBP), have a negative urine pregnancy test, and abstain from sexual activity or use a double barrier method (e.g. condom and diaphragm) of birth control from Day 1 and up to 2 days after study drug administration. 4. Willing to refrain from alcohol consumption within 24 hours of randomization 5. Are competent to provide informed consent 6. Voluntarily provide informed consent in accordance with governing International Review Board (IRB) requirements and provide Health Insurance Portability and Accountability Act (HIPAA) authorization, prior to any procedures or evaluations performed specifically for the sole purpose of the study 7. Indicate they understand and are able, willing, and likely to fully comply with study procedures and restrictions Exclusion Criteria: 1. Subjects scheduled for simultaneous bilateral or 2nd-eye cataract surgery (subjects scheduled for a future 2nd eye cataract surgery are eligible for the study) 2. Known sensitivity to benzodiazepines or ketamine 3. Known sensitivity to -caines (including proparacaine, ester-type local anesthetics), benzalkonium chloride (BAK) 4. Intraocular pressure (IOP) \> 30 mmHg in the study eye or fellow eye at screening. 5. History of iritis, or any ocular trauma with iris damage in the study eye 6. Presence of active corneal pathology other than dry eye per slit lamp and external eye exam at screening in either eye 7. Presence of extraocular/intraocular inflammation in either eye 8. Presence of active bacterial and/or viral infection in either eye 9. History of intraocular non-laser surgery in the study eye within the 3 months prior to day of surgery, or intraocular laser surgery in the study eye within 30 days prior to the day of surgery 10. Requiring or planning other additional ocular surgery during the cataract surgery (e.g. glaucoma surgery (\[minimally invasive or traditional\], limbal relaxing incisions, etc.) or performing laser-assisted CELR 11. Presence of active infection, mucositis, cold sores, canker sores, vesicles, viral lesions, local irritation/inflammation, or periodontal disease of the oral cavity. In addition, evidence of piercings of the tongue or anywhere in the oral cavity, history of oral cavity piercings, history of significant dental disease, or history of dysphagia. 12. Women who are nursing a child or plan to nurse a child during the study 13. Have a history or clinical manifestations (e.g., signs, symptoms, laboratory values, diagnostic imaging, etc.) of significant gastrointestinal, cardiovascular, hepatic, renal, hematological, endocrine, neurological, psychiatric, respiratory, or other medical condition that in the opinion of the investigator might confound the study results or pose additional risk in administering the study procedures 14. Use of disallowed medications including the following: 1. Antihypertensive agent or diabetic regimen at a dose that has not been stable for at least 30 days prior to Day 1, or which is not expected to remain stable throughout the study 2. Central nervous system (CNS) active drugs such as benzodiazepines, tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors (SNRIs), or selective serotonin reuptake inhibitors (SSRIs) that have not been stable for at least 30 days prior to Day 1, or which is not expected to remain stable throughout the study 3. Initiating the use of, switching to a different, or increasing the dose of a sleep medication (e.g. lorazepam, zolpidem, etc) within 3 days of randomization 15. Illicit drug use or alcohol abuse based on medical history, or currently engaged in illicit drug use or alcohol abuse. 1. Alcohol abuse is defined as 5 or more drinks in one sitting or 15 or more drinks in a week for men and 4 or more drinks in one sitting or 8 or more drinks in a week for women. A drink is considered a 1.5 oz shot, 12 oz of beer, or 5 oz of wine. 2. However, patients with a medical history of illicit drug use or alcohol abuse ≥ 5 years prior to the time of screening and who have recovered and have been drug/alcohol free for at least that period of time (i.e., 5 years) can be enrolled C. Patients with a medical history of medical or recreational marijuana (including THC and /or CBD) use ≥ 1 year prior to the time of screening and have been marijuana free for at least that period of time (i.e. 1 year) can be enrolled 16. Creatinine clearance rate \< 60 mL/min estimated using the CKD-EPI 2021cr (NKD) equation 17. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), or alkaline phosphatase (ALP) \> 2.5 times upper limit of normal (ULN), or total bilirubin \> 1.5 x ULN. In cases of documented Gilbert syndrome, subjects with elevated bilirubin levels will be permitted to enroll in the study if other liver function tests are within the specified limits 18. Any other abnormal laboratory results or presence of any condition that the Investigator believes would put the subject at risk or confound the interpretation of results