A Study to Evaluate the Pharmacokinetics of the Hydrocodone Extended-Release Tablet (CEP-33237) in Subjects With Normal Hepatic Function and Subjects With Moderate Hepatic Impairment

Inclusion Criteria: 1. All subjects: * Written informed consent is obtained 2. Subjects with normal hepatic function: * The subject is in generally good health (age-appropriate) as determined by medical and psychiatric history, physical examination, ECG, serum chemistry, hematology, coagulation, urinalysis, and serology. 3. Subjects with hepatic impairment: * The subject's health is otherwise clinically stable as determined by medical history, physical examination, ECG, serum chemistry, hematology, coagulation parameters (PT, activated partial thromboplastin time \[aPTT\], and international normalized ratio \[INR\]), urinalysis, and serology except for those signs and symptoms attributable to liver disease. * The subject has case record notes demonstrating physical signs consistent with 1 or more of the following characteristic clinical manifestations of liver cirrhosis: liver firmness to palpation, splenic enlargement, spider angiomas, palmar erythema, parotid hypertrophy, testicular atrophy, ascites (accumulation of fluid in the abdominal cavity), or gynecomastia. * The subject has a Child-Pugh Classification score of 7-9 points (moderate). Exclusion Criteria: 1. All subjects: * The subject has any clinically significant, uncontrolled medical condition. * The subject is a poor metabolizer of CYP2D6 substrates based on genotyping performed at screening. * The subject has previously participated in a study with CEP-33237. * The subject has a known sensitivity or idiosyncratic reaction to hydrocodone or hydromorphone, related compounds, or to any metabolites, or any compound listed as being present in a study formulation. 2. Subjects with normal hepatic function: * The subject has a positive test result for HBsAg or antibodies to hepatitis C. * The subject has a history of alcohol, narcotic, or any other substance abuse. 3. Subjects with hepatic impairment: * The subject has severe ascites. * The subject has an acute exacerbation of liver disease as indicated by worsening clinical signs of hepatic impairment.