Inclusion Criteria:

• Sex:Non-smoking Male or Female; similar proportions of each preferred.
• Age: At least 18 years.
• Weight: BMI less than 30.

• Qualifying subjects must be in good health and physical condition as determined by medical history, complete physical examination, and laboratory tests, all obtained within four (4) weeks prior to study start. The subject may not have a history of significant past illness expected to affect the investigation. The normal status of subjects will be confirmed by the following procedures:

  • Laboratory Tests: hemoglobin, hematocrit, RBC, WBC, differential count, serum electrolytes (Na, K, Cl), fasting blood glucose, BUN, bilirubin, creatinine, AST, ALT, LD, alkaline phosphatase, and urinalysis. HIV, Hepatitis B, Hepatitis C, and drugs of abuse testing will be done for screening purposes only. urine drugs of abuse testing will be repeated at each check-in. Female subjects will have a serum pregnancy test done at screening and a urine pregnancy test prior to each study period at check-in. Laboratory values which are greater than ± 20% of the normal range will not qualify unless specifically accepted (with comment) by the Principal Investigator. Results of HIV, Hepatitis B, Hepatitis C, and drugs of abuse must be negative or non-reactive for the subject to qualify for the study.
  • Electrocardiogram: A 12-lead electrocardiogram (ECG) will be obtained for all subjects. The original tracings, plus interpretation, will be included in the case report form packet.
• Subjects must read and sign the Consent Form.

Exclusion Criteria:

• Subjects not complying with the above inclusion criteria must be excluded from the study.

• In addition, any one of the conditions listed below will exclude a subject from the study:

  • History of treatment for alcoholism, substance abuse, or drug abuse within past 24 months.
  • History of malignancy, stroke, diabetes, cardiac, renal or liver disease, or other serious illness.
  • History of treatment for asthma within the past five (5) years.
  • History of treatment for any gastrointestinal disorder within the past five (5) years.
  • History of hepatic function impairment.
  • Females who are pregnant or lactating.
  • History of hypersensitivity to azithromycin, erythromycin, or any macrolide antibacterial agent.

• Conditions upon screening which might contraindicate or require that caution be used in the administration of azithromycin, including:

  * Sitting systolic blood pressure below 90 mmHg, or diastolic pressure below 50 mmHg.

  b. Heart rate less than 50 beats per minute after a 5-minute rest in a seated position.

• Inability to read and/or sign the consent form.
• Treatment with any other investigational drug during the four (4) weeks prior to the initial dosing for this study.
• Subjects who have donated blood within four (4) weeks prior to the initial dosing for this study.
• Subjects who smoke or use tobacco products or are currently using nicotine products (patches, gums, etc.) At least three (4) consecutive months of abstinence is required.