A study in stable epilepsy patients comparing levels of valproic acid after administration of brand and generic divalproex sodium extended release tablets.

Study consists of a screening visit, four treatment periods and a final follow-up visit. Each treatment period consists of a four night in-house stay followed by two outpatient visits. Each treatment period will be separated by a washout period. During each treatment period, safety evaluations will include vital signs, physical exams, safety laboratory tests, weight measurement, electrocardiograms, adverse event collection and concomitant medication recording. Pharmacokinetic blood samples will be collected during each treatment period. Seizure activity will be recorded in a seizure diary during the study. A standardized high-fat, high-calorie meal will be served prior to each dose during each treatment period.

Inclusion Criteria:

• Able to understand, sign and date the informed consent form
• Male or female 18 to 55 years old with a diagnosis of epilepsy who are stable
• Body mass 18 to 34 kg/m, inclusive
• Is continuously receiving a fixed dose of their AED medication(s)for a minimum of 30 days prior to screening
• Stay on the same dosages of their routine concomitant medications throughout the study
• Healthy, as determined by pre-study medical history, vital signs, physical exam, ECG and the opinion of the investigator
• Normal renal function per laboratory test
• No clinically relevant labs.
• Negative for hepatitis B, C and HIV
• For females, negative pregnancy test
• Negative for drugs of abuse and alcohol
• Nonsmoker or has not smoked within the past six months.
• Some over-the-counter medications may be permitted at the discretion of the investigator
• Able to communicate well and comply with study procedures, requirements and restrictions

Exclusion Criteria:

• History or presence of clinically significant medical disorders
• Have a current psychiatric disorder
• History of status epilepticus within 90 days of screening
• Any other condition that the investigator would feel could interfere with the safety of the subject or the study protocol.
• Taking three or more AED medications
• Use of felbamate, aspirin, carbapenem antibiotics, rifampin, ritonavir, macrolide antibiotics, cholestyramine, and/or risperidone.
• Use of any investigational agent or medical device within 30 days of screening.
• History of clinically significant drug allergy that in the opinion of the investigator may compromise the subject's safety or study results.
• History of known hypersensitivity to divalproex sodium or its excipients
• History of alcohol or drug abuse or dependence in the past 5 years
• Consumed alcohol, caffeine or other xanthine-containing foods or beverages within 48 hours prior to each clinic admission.
• Consumed grapefruit and/or grapefruit containing products within days prior to admission to the clinic on Day -1 and they agree not to consume grapefruit and/or grapefruit containing products for the duration of their study involvement
• Participated in any strenuous physical exercise within 72 hours before admission to the clinic on Day 1 and agrees to abstain from the duration of their study involvement.
• Acute illness at screening and/or at admission to the clinic
• Lactose intolerance or unusual dietary habits.
• Blood donation within 8 weeks of admission to this study