Bupropion Hydrochloride 300 mg Extended Release Tablets Under Fasting Conditions

Inclusion Criteria: * Male or female patients, 25 years of age or older * Diagnosis of any depressive disorder as per DSM IV criteria (except bipolar depression and major depressive disorder with psychotic features). Note: Both patients who are or are not being treated with bupropion or other antidepressants are permitted into the study. * Patients must have complained of suffering from adverse events and/or lack of effect when switched from Wellbutrin XL® 300 mg to Budeprion XL™ 300 mg. * BMI (kg/m2) Greater than or equal to 19 and less than or equal to 34. * No clinically significant abnormal laboratory values * No clinically significant findings in a 12-lead electrocardiogram (ECG) * No clinically significant findings in vital signs measurements. * Be informed of the nature of the study and give written consent prior to receiving any study procedure. Exclusion Criteria * Carcinoma within the last 5 years. Note: Patients with basal or squamous cell carcinoma may be permitted into the study on a case by case basis. * A history of epilepsy or risk for seizures. * A previous or current diagnosis of bipolar depression. * A current diagnosis of major depressive episode with psychotic features. Note: Subjects with previous diagnosis of major depressive episode with psychotic features may be included at the investigator's discretion. * A previous or current diagnosis of an eating disorder (e.g. bulimia, anorexia nervosa). * A lifetime history of schizophrenia or schizo-affective disorder. * Significant disease(s) or clinically significant finding(s) in a physical examination determined by an investigator to pose a health concern to the patient while on study. * Presence of clinically significant gastrointestinal disease and/or surgery (e.g. gastric bypass surgery) or history of malabsorption within the last year. * Known history or presence of an allergic sensitivity to bupropion and/or any other drug substances with similar activity. * Expected changes in use of permitted concomitant medication that will be continued throughout the study. * Undergoing abrupt discontinuation of sedatives (including benzodiazepines). * Use of monoamine oxidase inhibitors (MAOI) within 2 weeks prior to study admission. * Taking medications that interact with CYP2B6 within 30 days prior to Day 1 dosing. * Taking levodopa, amantadine, drugs that lower seizure threshold (e.g. theophylline, systemic steroids, antipsychotics), and/or on nicotine replacement therapy. * History of alcohol or drug-dependence by DSM IV criteria within 6 months prior to study admission. * Positive test results for: * HIV * Hepatitis B surface antigen or Hepatitis C antibody * Urine drugs of abuse (i.e. marijuana, amphetamines, barbiturates, cocaine, opiates, methadone, and phencyclidine) Note: any positive test result(s) for benzodiazepine(s) must be assessed by the investigator to determine whether the patient should be excluded from this study. * Serum hCG consistent with pregnancy (females only). * On a special diet within 30 days prior to study admission (e.g. liquid, protein, raw food diet). * Difficulty fasting or consuming standard meals. * Participated in another clinical trial or received an investigational product within 45 days prior to Day 1 drug administration. * Donation or loss of whole blood: * Less than or equal to 499 mL within 30 days prior to dosing * Greater than or equal to 500 mL within 56 days prior to dosing Note: blood taken for routine medical evaluations totaling less than 50 mL will be permitted. * Females who have discontinued the use of: * implanted, intrauterine, or injected hormonal contraceptives within 6 months prior to Day 1 drug administration, OR * oral, intravaginal, or patch hormonal contraceptives within 1 month prior to Day 1 drug administration * Females who started taking: * implanted or intrauterine hormonal contraceptives less than 6 months prior to Day 1 drug administration, OR * oral, intravaginal, patch, or injected hormonal contraceptives less than 3 months prior to Day 1 drug administration. * Females who are pregnant, lactating, or likely to become pregnant during the study. * Have had a newly applied tattoo or body piercing within 30 days prior to study admission. * Does not tolerate venipuncture. * Unable or unwilling to provide informed consent.