The purpose of this study is to determine the pharmacokinetics, safety, and tolerability of RDC-0313 following oral administration.

This is a single-center, randomized, double-blind, ascending dose, placebo controlled study. Dosing sequences will consist of 5 administrations of an oral solution of either ascending doses of RDC-0313 or volume-match placebo. Dosing of cohorts will be staggered to allow a blinded safety review to occur prior to dosing the next cohort. Subjects will be admitted to the facility the morning before each dose, and will be required to fast overnight prior to study drug administration. They will be discharged from the facility after the 36-hour postdose assessments are completed.

Inclusion Criteria:

• 18 - 65 years of age
• Body mass index of 19-30 kg/m2 at screening
• If subject is female and of childbearing potential, she must agree to use an acceptable method of contraception
• If subject is male, he must agree to reduce the risk of a female partner becoming pregnant

Exclusion Criteria:

• Pregnancy and/or currently breastfeeding
• Clinically significant medical condition or observed abnormalities
• Clinically significant illness within 30 days of the first study drug administration
• History of opioid dependence
• Positive urine toxicological screen for marijuana, cocaine, amphetamines, opioids, barbiturates, and benzodiazepines
• Positive resolut for any serology test performed at screening
• Use of alcohol-, caffeine-, or xanthine-containing products
• Tobacco use within 90 days before the first study drug administration
• Participation in a clinical trial within 30 days before screening
• Requirement of a special diet other than vegetarian, or significant food allergy or intolerance