To compare the rate and extent of absorption of doxycycline monohydrate capsules equivalent to 100 mg doxycycline (Par) versus Monodox (Oclassen Pharmaceuticals).

To compare the rate and extent of absorption of doxycycline monohydrate capsules equivalent to 100 mg of doxycycline by Par Pharmaceutical, Inc., USA (test) versus Monodox by Oclassen Pharmaceuticals, Inc., USA reference administered as a 1 x 100 mg capsule under fasting conditions.

Inclusion Criteria:

• Subjects will be males, non-smokers
• Between 18 and 55 years of age
• Subjects weight will be within 15% of their ideal body weight, based on Table of "Desirable Weight of Adults", Metropolitan Life Insurance Company, 1983
• Subjects should read, sign and date an Informed Consent Form prior to any study procedures
• Subjects must complete all screening procedures within 28 days prior to the administration of the study medication

Exclusion Criteria:

• Clinically significant abnormalities found during medical screening
• Any clinically significant history of ongoing problems or problems known to interfere with the absorption, distribution, metabolism or excretion of drugs of drugs
• Clinically significant illnesses within 4 weeks of the administration of study medication
• Abnormal laboratory tests judged clinically significant
• ECG or vital sign abnormalities (clinically significant)
• History of allergic reactions to heparin
• Any food allergies, intolerances, restrictions, or special diet which in the opinion of the medical subinvestigator, contraindicates the subject's participation in the study
• History of severe allergies or hay fever
• Active asthma or bronchospasm
• Positive urine drug screen at screening
• Positive testing for hepatitis B, hepatitis C or HIV at screening
• Use of investigational drug or participation in an investigational study, within 30 days prior to administration of the study medication
• Recent donation of plasma (500 mL) within 7 days or recent donation or significant loss of whole blood (450 mL) within 56 days prior to the administration of the study medication
• History of significant alcohol abuse within six months of the screening visit or any indication of the regular use of more than two units of alcohol per day
• Recent history of drug abuse or use of illegal drugs: soft drugs (marijuana, pot) use within 3 months of the screening visit and hard drugs (cocaine, PCP, crack) use within 1 year of the screening visit
• Subjects who have taken prescription medication 14 days preceding administration of study medication or over-the-counter products 7 days preceding administration of study medication, except for topical products without systemic absorption
• Subjects who have taken any drugs known to induce or inhibit hepatic drug metabolism within 30 days prior to administration of the study medication
• Subjects who have undergone clinically significant surgery within 4 weeks prior to the administration of the study medication
• Any reason which, in the opinion of the medical subinvestigator, would prevent the subject from participating in the study