The purpose of this study is to evaluate and compare the relative bioavailability of a test formulation of zonisamide capsules to an equivalent dose of a reference formulation, Zonegran® (zonisamide) capsules, after a single oral dose administered under fasting conditions.

The purpose of this study is to evaluate and compare the relative bioavailability of a test formulation of zonisamide capsules to an equivalent dose of a reference formulation, Zonegran® (zonisamide) capsules, after a single oral dose administered under fasting conditions.

Thirty-four healthy, non-smoking, non-obese male and female volunteers at least 18 years of age will be randomly assigned in a crossover fashion to receive each of two zonisamide dosing regimens in sequence with a 28 day washout period between dosing periods. On the morning of Day 1, after an overnight fast, subjects will receive either a single oral dose of the test formulation, zonisamide (1 x 100 mg capsule) or a single oral dose of the reference formulation, Zonegran® (1 x 100 mg capsule). After a 28 day washout period, on the morning of Day 29 after an overnight fast, subjects will receive the alternate regimen. Blood samples will be drawn from all participants before dosing and for 72 hours post dose at times sufficient to adequately define the pharmacokinetics of zonisamide. A further goal of this study is to evaluate the safety and tolerability of this regimen in healthy volunteers. Subjects will be monitored throughout the confinement portion of the study for adverse reactions to the study drug and/or procedures. Blood pressure and heart rate will be obtained prior to dosing and as scheduled following dose administration. All adverse events whether elicited by query, spontaneously reported or observed by clinic staff will be evaluated by the investigator and reported in the subject's case report form.

Inclusion Criteria:

• Screening Demographics:
• All volunteers selected for this study will be healthy men and women 18 years of age or older at the time of dosing
• Weight range will not exceed ± 20% for height and body frame
• Screening Procedures:
• Each volunteer will complete the screening process within 28 days prior to Period I dosing
• Consent documents for both the screening evaluation and HIV antibody determination will be reviewed, discussed, and signed by each potential participant before full implementation of screening procedures
• Screening will include general observation, physical examination, demographics, medical and medication history, an electrocardiogram, sitting blood pressure and heart rate, respiratory rate and temperature
• The physical examination will include, but may not be limited to, an evaluation of the cardiovascular, gastrointestinal, respiratory and central nervous systems
• The screening clinical laboratory procedures will include: Hematology, Clinical Chemistry, HIV antibody, Hepatitis B-surface antigen, Hepatitis C antibody, Urinalysis, Urine Drug Screen, Serum Pregnancy Screen, Follicle Stimulating Hormone
• If female: postmenopausal for 1 year or surgically sterile.

Exclusion Criteria:

• Volunteers with a recent history of drug or alcohol addiction or abuse
• Volunteers with the presence of a clinically significant disorder involving the cardiovascular, respiratory, renal, gastrointestinal, immunologic, hematologic, endocrine, or neurologic system(s) or psychiatric disease
• Volunteers whose clinical laboratory test values are outside the accepted reference range and when confirmed on re-examination are deemed to be clinically significant
• Volunteers demonstrating a reactive screen for hepatitis B surface antigen, hepatitis C antibody or HIV antibody screen
• Volunteers demonstrating a positive drug abuse screen when screened for this study
• Female volunteers demonstrating a positive pregnancy screen
• Female volunteers who are currently breastfeeding
• Volunteers with a history of allergic response(s) to zonisamide or related drugs
• Volunteers with a history of clinically significant allergies including drug allergies
• Volunteers with a clinically significant illness during the 4 weeks prior to Period I dosing (as determined by the clinical investigator)
• Volunteers who currently use tobacco products
• Volunteers who have taken any drug known to induce or inhibit hepatic drug metabolism in the 28 days prior to Period I dosing
• Volunteers who report donating greater than 150mL of blood within 28 days prior to Period I dosing. All subjects will be advised not to donate blood for four weeks after completing the study
• Volunteers who report receiving any investigational drug within 14 days prior to Period I dosing.
• Volunteers who have donated plasma(e.g. plasmapheresis) within 14 days prior to Period I dosing. All subjects will be advised not to donate plasma for four weeks after completing the study
• Volunteers who report taking any systemic prescription medication in the 14 days prior to Period I dosing.