Researchers want to find out how Minocycline Extended-Release Tablets affect sperm-production in healthy males.

The study will include Minocycline Extended-Release Tablets, a new once-daily formulation of minocycline, compared with a placebo or inactive pill.

Approximately 170 healthy adult males will be assigned by chance (like flipping a coin) to 2 treatment groups with approximately 85 subjects per group. You will be treated with either Minocycline Extended-Release Tablets or placebo once daily. Screening will occur within 14 days prior to the first dose of study drug.

Required study activities include:

• Written informed consent
• Weight
• Two semen collections within 48-72 hours of one another at the screening visit and Days 84,112, 140, and 168
• Blood draws at the screening visit and Days 84, 112, 140, and 168
• Genital examination (excluding prostate) at screening and at the Day 84 and Day 112 visits
• Medical history

You will continue in the treatment phase of the study for 12 weeks.

You will return to the clinic 4 weeks and 8 weeks after completion of the treatment phase of the study, with the final study visit approximately 12 weeks after the last dose.

Participation will be for 24-weeks.

Up to 10 investigational sites will enroll subjects into the study.

Inclusion Criteria:

• Males at least 18 years of age
• Weight 45 kg - 136.36 kg (99-300 lbs)
• Must understand and give consent voluntarily to be in the study and to comply with study requirements
• Subjects must ejaculate between 48 and 72 hours prior to collection of the first specimen (Pre-Collection Ejaculation) and refrain from further ejaculation until Specimen 1 is collected. The second ejaculation sample Specimen 2) must be collected between 48 hours and 72 hours after Specimen 1. No ejaculation is permitted between Specimen 1 and Specimen 2
• Must refrain from using saunas or hot tubs during the duration of the study 168 days)
• Must be a non smoker
• Must be medically healthy as determined by the investigator physician (via medical history and clinical laboratory tests)
• Must have sperm parameters (average of Specimen 1 and Specimen 2) within clinically acceptable limits at screening defined as:
• Total sperm concentration ≥20 x 106/mL10
• % motile ≥50%10
• % normal morphology >4.4%14

Exclusion Criteria:

• Known allergy/sensitivity to minocycline or any of the other drug product components
• Use of antacids or other dietary supplements containing aluminum, calcium, iron, or magnesium
• History of vestibular incidents including vertigo, lightheadedness, nausea, or vomiting within the 30 days prior to enrollment
• Known history of alcohol or drug dependency, significant within the past 2 years
• Known history or current risk of hepatic dysfunction
• Known history or current risk of renal dysfunction, e.g., uncontrolled diabetes
• Systemic lupus erythematosis (SLE) or a positive ANA at screening
• Receipt of any experimental drugs within 120 days prior to Study Day 0
• Non-LFT clinical laboratory values outside the normal range and determined to be of clinical significance
• Liver function tests greater than 1.5 times the upper limit of normal (ALT, AST, GGT)
• Use of tetracyclines, erythromycin within 12 weeks of Day 0