The current study is conducted to evaluate and compare the relative bioavailability for Quetiapine in two different products containing 25 mg Quetiapine after a single oral dose administration under fasting conditions.

A randomized, single-dose, partial replicate, three-phase, three-sequence, bioequivalence study of the two study products. Blood samples were collected at different time intervals and stored at -70⁰C freezer. Quetiapine plasma concentrations were analyzed using a validated LC-MS-MS method then pharmacokinetics and statistical analysis were performed on the concentrations obtained using Phoenix WinNonlin® software.

Inclusion Criteria:

• Written informed consent is obtained for study.
• Age 18 - 55 years,
• Body mass index between 18.5 and 30 kg/m2
• Have no clinically significant diseases captured in the medical history or evidence of clinically significant findings on physical examination.
• Vital signs without significant deviations.
• All laboratory screening results are within the normal range or clinically non-significant.

Exclusion Criteria:

• History or presence of any disorder or condition that would render the subject unsuitable for the study, place the subject at undue risk or interfere with the ability of the subject to complete the study in the opinion of the investigator.
• History of any significant cardiovascular, hepatic, renal, respiratory, gastrointestinal, endocrine, immunologic, allergic, dermatologic, hematologic, neurologic, or psychiatric disease, or cancer.
• Any confirmed significant allergic reactions against any drug, or multiple allergies.
• Clinically significant illness 28 days before study phase I.
• Alcohol or any solvent intake.
• Regular use of medication.
• Positive urine screening of drugs of abuse.
• Use of any systemic medications (prescription medications, OTC products, supplements, or herbal preparations) for 14 days prior to dosing and during the study.
• History or presence of significant smoking (more than one pack per day cigarettes) or refusal to abstain from smoking for 48 hours before dosing until checkout.
• Blood donation within the past 60 days.
• Participation in another bioequivalence study within 60 days prior to the start of phase I of the study.