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

The goal of this clinical trial is to learn if MELT-300 works on procedural sedation in adult participants undergoing cataract extraction with lens replacement (CELR). It will also learn about the safety of MELT-300. Researchers will compare MELT-300 to a placebo (a look-alike substance that contains no drug) to see if MELT-300 works on procedural sedation in adult participants undergoing CELR. Researchers will also include a comparator SL midazolam to confirm the benefit of inclusion of ketamine in the combined drug product. The main questions it aims to answer are: 1. Does MELT-300 is effective in comparison to placebo on procedural sedation for cataract surgery? 2. To determine the effectiveness of MELT-300 compared with midazolam on procedural sedation (to determine the contribution of ketamine component and inform the risk of ketamine in MELT-300) 3. To determine the time to achieve preoperative target sedation level with MELT-300 4. What medical problems do participants have when taking MELT-300 vs placebo Eligible participants will admitted to the study unit on Day 1. Participants will be randomized prior to surgery 4:1:1 to 1. MELT-300 (i.e. 1 MELT-300 sublingual tablet which contains 3 mg midazolam and 50 mg of ketamine) 2. Midazolam (i.e. 1 matching midazolam sublingual tablet which contains 3 mg midazolam) 3. Placebo (i.e. 1 matching placebo sublingual tablet) Participants will receive study medication 30 (± 5) minutes, without food or water, before planned surgery start (defined as instillation of topical ocular anesthetic gel \[i.e.. 3 drops of chloroprocaine hydrochloride ophthalmic gel)\]. The effectiveness of MELT-300 will be performed after study medication is administered before surgery, in the course of surgery, and postoperative on Day 1 (end of surgery defined as just prior to drape removal). The safety of MELT-300 will be performed at baseline, in the course of surgery, postoperatively on Day 1, and on Day 3 ± 1 day post dose of study medication.