To compare the relative bioavailability of Kali and Ortho-McNeil's

To compare the relative bioavailability of Kali's Tramadol/APAP 37.5mg/325mg with Ortho-McNeil's Ultracet tablets 37.5mg/325mg

• Drug: Tramadol APAP
• Drug: Ultracet

• Experimental: Subjects received kali product under fasting conditions
• Active Comparator: Subjects received Ortho-Mcneil product under fasting conditions

Inclusion Criteria:

• Healthy Males and females between 18 and 45 years of age inclusive
• Informed of the nature of the study and given written informed consent.
• Have a body weight within 15% of the appropriate range as defined in the 1983 Metropolitan Life Company tables and weighing at least 100lbs.

Exclusion Criteria:

• Hypersensitivity to Tramadol/ Acetaminophen, opioids such as morphine and codeine, or related compounds, or a history or seizures.
• Any history of a clinical condition which might affect drug absorption, metabolism or excretion.
• Recent history (within one year) of mental illness, drug illness, drug abuse or alcoholism.
• Donation of greater than 500mL of blood in the past 4 weeks prior to study dosing or difficulty in donating blood.
• Received an investigational drug within the 4 weeks prior to study dosing.
• Currently taking any prescription medication, except oral contraceptives, within 7days prior to study dosing or over-the-counter medication within 3 days of the study dosing.
• This prohibition does not include vitamins or herbal preparations taken as nutritional supplements for non-therapeutic indications as judged by the physician.
• Tobacco use(>5 cigarettes per day)in the 3 months prior to study dosing.
• If female, the subject is lactating or has a positive pregnancy test at screening and prior to each of the two treatment periods.
• Females of child bearing potential must use a medically acceptable method of contraception throughout the entire study period and for one week after the study is completed.
• Medically acceptable methods of contraception that may be used by the subject and/or her partner are:oral contraceptive, progestin injection or implants, condom with spermicide, diaphragm with spermicide, IUD, vaginal spermicidal suppository, surgical sterilization of their partner(s) or abstinence.
• females taking oral contraceptives must have taken them consistently for at least three months prior to receiving study medication.