The purpose of this study is to determine the efficacy (based on the pharmacokinetic profile of testosterone) and safety of TBS-1 in the treatment of hypogonadal men

This study is a 4 Period study consists of 16 visits with overnight clinic stays that span over year to help determine the efficacy of TBS-1 gel administered twice daily (b.i.d) and three times daily (t.i.d)

In addition, this study will investigate the safety and tolerability of TBS-1 after 90, 180 and 360 days of treatment.

Inclusion Criteria

• Male between 18 and 80 years of age
• Able to understand and provide signed informed consent
• Have 2 fasting morning (0900 h ± 30 min) serum total testosterone levels <300 ng/dL
• Body mass index between 18.5 kg/m2 and 35 kg/m2
• Hemoglobin level > or = 13.0 g/dL
• Screening laboratory assessments within ±15% of the normal range, with the exception of liver function tests (which need to be within the normal range) and HbA1c (which must be <7.0% [9.5 mmol/L]); lipid profile and endocrine profile assessments are also exempt from this range unless the assessments indicate a significant intercurrent illness other than testosterone deficiency
• Ear, nose and throat examination including nasal endoscopy without clinically significant abnormal findings
• Normal prostate for age based on digital rectal exam and a serum PSA <4.0 ng/mL.

Exclusion Criteria

• Significant intercurrent disease of any type, in particular liver, kidney, heart disease, or psychiatric illness
• Hyperparathyroidism, uncontrolled diabetes mellitus, hypothyroidism, or hyperthyroidism (thyroid stimulating hormone should be <1.5 times the upper limit of normal)
• Hematocrit >54% at screening
• History of pituitary or hypothalamic tumors or history of malignancy within the past 5 years, excluding basal cell or squamous cell carcinoma of the skin curatively treated by surgery
• History of nasal surgery, specifically turbinoplasty, septoplasty, rhinoplasty, "nose job," or sinus surgery
• History of nasal fractures within the past 6 months and/or prior nasal fractures that caused a severely deviated anterior nasal septum
• Active allergies, such as rhinitis, rhinorrhea, and nasal congestion
• Mucosal inflammatory disorders, specifically pemphigus or Sjogren's syndrome
• Sinus disease, specifically acute sinusitis, chronic sinusitis, or allergic fungal sinusitis
• History of nasal disorders (eg, polyposis, recurrent epistaxis [>1 nose bleed per month], abuse of nasal decongestants) or sleep apnea
• Use of any form of intranasal medication delivery, specifically nasal corticosteroids and oxymetazoline-containing nasal sprays (eg, Dristan® 12-Hour Nasal Spray)
• History of severe adverse drug reaction or leukopenia
• A known hypersensitivity to lidocaine or any materials that may be used during the study
• History of abnormal bleeding tendencies or thrombophlebitis unrelated to venipuncture or intravenous cannulation
• History of hepatitis B, a positive test for hepatitis B surface antigen, a history of hepatitis C, or a positive test for hepatitis C antibody
• Presence of human immunodeficiency virus infection or antibodies
• History of asthma and ongoing asthma treatment
• History of sleeping problems or a shift worker
• Smoker of >10 cigarettes (or equivalent) per day
• Regular consumption of more than 4 units of alcohol daily (1 unit is defined as 300 mL of beer, 1 glass of wine, or 1 measure of spirit) or difficulty abstaining from alcohol during the 48 hours prior to the 24 hour blood sampling visits
• History or current evidence of abuse of alcohol or any drug substance, licit or illicit, or positive urine drug and alcohol screen
• Treatment with androgen therapy within at least 2 weeks prior to baseline evaluations (subjects on androgen therapy will require a washout period of 4 weeks for depot products administered intramuscularly [eg, testosterone enanthate 200 mg/mL] and 2 weeks for products administered orally or topically [oral, patch, gel, or buccal])
• Current treatment with other androgens (eg, dehydroepiandrosterone [DHEA]), anabolic steroids, or other sex hormones
• Treatment with estrogens, gonadotropin-releasing hormone (GnRH) agonists, or growth hormone within previous 12 months
• Treatment with drugs that interfere with the metabolism of testosterone, such as anastrozole, clomiphene, dutasteride, finasteride, flutamide, ketoconazole, spironolactone, or testolactone
• Treatment with any antihypertensive, antidepressant, tranquilizer, or histamine 2 (H2) receptor blocker that is not part of a stable regimen (stable dose for at least 3 months prior to baseline);
• Poor compliance history or low likelihood of maintaining attendance
• Participation in any other research study during the conduct of this study or 30 days prior to the initiation of this study or blood donation at any time during this study and within the 12 week period prior to screening