Aerosolized and Intravenous Colistin in Healthy Adults

1. Informed consent obtained and signed 2. Aged between 18 and 45 years, inclusive 3. Body Mass Index (BMI, weight in kg divided by the square of height in meters) between 18 and 35.0 kg/m\^2, inclusive 4. Able to comply with protocol requirements for the entire duration of the study 5. Healthy on the basis of a screening medical evaluation (including physical examination, vital signs, blood biochemistry and hematology, urinalysis, and history).

Exclusion Criteria:

1. Heterosexually active females of child-bearing potential, defined as being physiologically capable of becoming pregnant, unless they agree to use two of the following acceptable methods of contraception throughout their participation in the study and for at least 12 weeks after the final dose: (a) established use of oral, injected or implanted hormonal contraception, (b) intrauterine Device (IUD or Coil) (c) a female barrier method (diaphragm or cervical/vault cap) and/or (d) condom plus spermicidal cream/gel 2. Heterosexually active males unless they agree to use two concomitant acceptable methods of contraception throughout their participation in the study and for at least 12 weeks after receiving their final dose of study medication (examples include: vasectomy combined with latex condom with spermicide, latex condom with spermicide combined with a female partner who practices an acceptable method of contraception as indicated above) 3. History or current abuse of alcohol, barbiturates, amphetamines, tetrahydrocanninol, phencyclidine, cocaine, heroin, or other narcotics, as evidenced by a reported history or positive screen for these agents 4. Any clinically significant (as deemed by the Principal Investigator) history of asthma; cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal (including eating disorders), endocrine, metabolic, immunologic, dermatologic, neurologic (including a history of seizures, ataxia, or Myastenia Gravis), psychological, or psychiatric disease; and/or a past or family history of porphyria 5. Use of tobacco/nicotine within 3 months prior to Screening and for the entire duration of the study); 6. Treatment with another investigational drug 60 days prior to and/or during the study 7. Co-enrollment in another study involving the intake of medication 8. Immunocompromised status, including a positive HIV-1 (Human Immunodeficiency Virus) or HIV-2 test by ELISA at screening 9. Previously demonstrated clinically significant allergy or hypersensitivity to colistimethate sodium or its excipients 10. Donation of blood or significant blood loss within 56 days of study Enrollment or during study duration, or plasma donation within 28 days preceding study Enrollment 11. Hepatitis B, or C infection (confirmed by hepatitis B surface antigen, or hepatitis C virus antibody, respectively) at screening 12. Laboratory abnormalities at Screening as outlined below: a. Serum creatinine (>/=1.1 x ULN), b. Hemoglobin (\<11.0 or >17.5g/dL), c. Platelet count (\<125,000 or >450,000/mm\^3), d. Absolute neutrophil count (\<1300mm\^3), e. Serum blood urea nitrogen (>/=1.2 x ULN) f. Aspartate aminotransferase (AST, >/=1.2 x ULN), g. Alanine aminotransferase (ALT, >/=1.2 x ULN), h. Proteinuria (spot urine) greater than trace and/or hematuria greater than trace; Note: Subjects may undergo a repeat screening test of out-of-range analyte(s) at the discretion of the investigator to confirm a plausible alternative explanation that will be indicated in the source documentation. A repeat laboratory test may be used to satisfy eligibility requirements. 13. Intake of any of the following medications within 30 days prior to Screening and during the study: acyclovir, adefovir, aminoglycosides, amphotericin, cisplatin, cyclosporine, fluoroquinolones, foscarnet, ganciclovir, pamidronate, sirolimus, tacrolimus, and vancomycin, and/or any neuromuscular blockers;- Intake of NSAIDs (ibuprofen, naproxen, etodolac) within 48 hours of dosing and any inhaled medication within 5 days of dosing. Additionally, subjects may be excluded due to intake of medications not listed here at the discretion of the PIs (Principal Investigators) 14. Intake of NSAIDs (ibuprofen, naproxen, etodolac) within 48 hours of dosing and any inhaled medication within 5 days of dosing. Additionally, subjects may be excluded due to intake of medications not listed here at the discretion of the PIs; 15. FEV1 (Forced Expiratory Volume) \<80 percent predicted 16. Prior evidence (symptoms within the past year) of vestibular problems or neuropathy 17. Abnormal QT interval at screening ECG (Electrocardiogram) (Bazett correction >450 milliseconds) or significant abnormities according to the cardiologist's final reading 18. A grade 3 or 4 clinical or confirmed laboratory toxicity (as outlined in Appendix C) which does not return to grade 2 or lower; 19. Any condition that would, in the opinion of the investigator, place the subject at an unacceptable risk or injury, or render the subject unable to meet the requirements of the protocol.