A Phase 1 MAD Study to Evaluate the Safety and Tolerability of LY03020

• LY03020 (Drug): administered orally
• Placebo (Drug): administered orally

Primary outcomes

• Number of participants with adverse events (AEs) and serious adverse events (SAEs). [up to Day 11]

Secondary outcomes

• Number of participants with clinical laboratory assessment abnormalities. [up to Day 11]
• Change from Baseline in Positive and Negative Syndrome Scale (PANSS) at Day 11 of subjects with stable schizophrenia [up to Day 11]: The total score range is 30 to 210.A higher score is associated with greater illness severity.
• Change from Baseline in Columbia - Suicide Severity Rating Scale (C-SSRS) at Day 11 of subjects with stable schizophrenia [up to Day 11]: This scale is divided into three parts, which are evaluated suicidal ideation(5 items \[yes/no\])，intensity of ideation (5 items on 5-point scales; scores range from 0 to 25 with higher scores indicating more intense suicidal ideation),and suicide behavior(actual attempt,interrupted attempt,aborted attempt, preparatory acts or behavior).
• Change from Baseline in Barnes Akathisia Rating Scale (BARS) at Day4 and Day 11 of subjects with stable schizophrenia [up to Day 11]: The total score range is 0 to 14.A higher score is associated with greater illness severity.
• Change from Baseline in Simpson-Angus Scale (SAS) at Day4 and Day 11 of subjects with stable schizophrenia [up to Day 11]: This scale consists of 10 items, and each question is scored from 0 to 4 points. The Total score range is 0 to 40.A higher score is associated with greater illness severity.
• Maximum observed concentration at steady state (Cmax,ss) of LPM787000048 in plasma [up to Day 11]
• Minimum observed concentration at steady state (Cmin,ss) of LPM787000048 in plasma [up to Day 11]
• Area under the concentration- time curve during the dosing interval at steady state (AUC0-τ,ss) of LPM787000048 in plasma [up to Day 11]
• Area under the concentration-time curve from time zero extrapolated to infinity at steady state (AUC0-∞,ss) of LPM787000048 in plasma [up to Day 11]
• Time to maximum observed concentration at steady (Tmax,ss) state of LPM787000048 in plasma [up to Day 11]
• Apparent terminal elimination half-life (t1/2) of LPM787000048 in plasma [up to Day 11]
• AUC Accumulation Ratio (Ra(AUC)) of LPM787000048 in plasma [up to Day 11]
• Cmax Accumulation Ratio (Ra(Cmax)) of LPM787000048 in plasma [up to Day 11]
• Number of participants with vital sign abnormalities. [up to Day 11]
• Number of participants with 12-lead electrocardiogram abnormalities (ECGs). [up to Day 11]
• Number of participants with ophthalmic examination abnormalities. [up to Day 11]

Sex: All, ages: 18 Years to 60 Years, accepts healthy volunteers

Inclusion Criteria:

Healthy Subjects

* Subjects sign informed consent voluntarily.
* Male or female aged 18 to 45 years.
* Body weight ≥ 50.0 kg for male and ≥ 45.0 kg for female, and body mass index (BMI) between 18.5 and 26.0 kg/m2 Subjects with Stable Schizophrenia
* Subjects themselves and / or their guardians sign informed consent voluntarily.
* Male or female aged 18 to 60 years.
* Body weight ≥ 50.0 kg for male and ≥ 45.0 kg for female, and body mass index (BMI) between 18.5 and 32.0 kg/m2.
* Subject must meet the DSM-V criteria for a primary diagnosis of schizophrenia. Subject must have a PANSS total score ≤ 80 and CGI-S score ≤ 4 at screening. The condition is stable from 1 month before signing informed consent to baseline.

Exclusion Criteria:

Healthy Subjects

* Subjects have any clinically significant medical condition or chronic disease.
* Subjects have used any of nonprescription drugs within 7 days or prescription drugs within 28 days prior to administration.
* Subjects experienced a history of keratopathy, fundus disease, increased intraocular pressure, or angle-closure glaucoma. Subjects have any abnormal and clinically significant test for ophthalmic examination during screening.
* Subjects with a history of orthostatic hypotension or syncope.
* Subjects with condition that may interfere with the drug absorption, distribution, metabolism and excretion significantly.
* Subjects had a history of surgery within 3 months prior to administration, or had not recovered, or have a surgical plan during the study.
* Subjects have any clinically significant abnormal vital signs, laboratory values, and ECGs.
* Subjects have a history of allergic diseases, or allergic to any substance contained in the formulation
* Subjects have a positive test for HBsAg, HCV-Ab, HIV-Ab, or syphilis antibody. Subjects with Stable Schizophrenia
* According to the DSM-5, there were other mental disorders except schizophrenia within 6 months before screening period.
* Assessed by the investigator as having treatment-resistant schizophrenia; past or current diagnosis of neuroleptic malignant syndrome (NMS); anticipated need for antipsychotic regimen modifications during the study period;
* History of suicide attempts (including actual attempts, interrupted attempts, or failed attempts) or suicidal ideation within the past 6 months, defined as affirmative responses ("yes") to question 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) at screening/baseline;
* Subjects have used monoamine oxidase inhibitors (MAOI) within 28 days or any dietary supplements/traditional Chinese herbal products within 7 days prior to first dosing.
* Glycated hemoglobin (HbA1c) ≥7% at screening/baseline.
* Congenital long QT syndrome; uncontrolled or severe cardiovascular disease, including NYHA class II or higher congestive heart failure, unstable angina, myocardial infarction within 6 months prior to screening, or presence of treatment-requiring severe arrhythmias (e.g., sustained ventricular tachycardia, ventricular fibrillation, torsades de pointes) at screening; resting heart rate <50 beats per minute (bpm) at screening/baseline; or QTc >450 ms (male) / QTc >460 ms (female) based on Fridericia's formula-corrected measurements at screening/baseline.
* Subjects experienced a history of keratopathy, fundus disease, increased intraocular pressure, or angle-closure glaucoma. Subjects have any abnormal and clinically significant test for ophthalmic examination during screening.
* Subjects with a history of orthostatic hypotension or syncope.