Inclusion criteria:

• Healthy subjects defined as individuals who are free from clinically significant illness or disease as determined by the investigator based on their medical history, physical examination, laboratory studies, ECGs, and other tests.
• Males who are 18 - 45 years of age, inclusive.
• Weight range 55 - 95 kg (inclusive) and body mass index 19 - 30 kg/m2 (inclusive).
• Willing and able to give written informed consent, willing to participate for the full duration of the study, and able to understand and follow instructions related to study procedures

Exclusion criteria:

• Slow metabolizer for CYP2D6 as determined by screening PGx analysis.
• History of postural hypotension, dizziness, poor hydration, vertigo, vaso-vagal reactions or any other signs and symptoms of orthostasis, which in the opinion of the investigator could be exacerbated by tamsulosin and result in putting the subject at risk of injury.
• Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements within 7 days (or 14 days if the drug is a potential enzyme inducer, such as St. John's Wort) or 5 half-lives (whichever is longer) prior to the first dose of study medication, unless in the opinion of the investigator and sponsor the medication will not interfere with the study procedures or compromise subject safety.
• Chronic hepatitis B and C, as evidence by positive Hepatitis B surface antigen (HBsAg) or Hepatitis C antibody.
• Positive HIV test at screening.
• History of sensitivity to heparin or heparin-induced thrombocytopenia.
• History of regular alcohol consumption exceeding 14 drinks/week for men (1 drink = 5 ounces of wine or 12 ounces of beer or 1.5 ounces of hard liquor) within 6 months of screening. Subjects must be able and willing to abstain from beverages and foods containing alcohol 24 hours prior to and during the dosing day.
• A positive urine drug or alcohol (Breath test or urine) screen result at screening or check-in..
• The subject has received an investigational drug or participated in any other research trial within 30 days or 5 half-lives, or twice the duration of the biological effect of any drug (whichever is longer) prior to the first dose of current study medication or anytime during the study period.
• Where participation in study would result in donation of blood in excess of 500 mL within a 56 day period.
• History or presence of allergy, intolerance, or contraindication to tamsulosin HCl or AVODART or drugs of this class, or a history of drug or other allergy (including true sulfonamide allergy) that, in the opinion of the physician responsible, contraindicates their participation.
• Subjects who have consumed the following foods or drinks within 7 days prior to the first dose of study medication or at any time during the clinical phase of the study: grapefruit juice; red wine; grapefruit or cruciferous vegetables (watercress, broccoli, cabbage, Brussels sprouts).
• QTc ≥ 450 msec at screening.