This is a 2 week Phase 1 study of SB204 (NVN1000 Gel) in healthy adult volunteers with elevated Propionibacterium acnes (P. acnes) counts. Subjects will apply NVN1000 4% Gel or Vehicle Gel twice daily to their face. Assessments will include cutaneous tolerability, safety, and P. acnes counts.

In this single-center, vehicle gel-controlled, evaluator and subject blinded study, approximately 30 otherwise healthy adult subjects with elevated P. acnes counts will be randomized 2:1 to NVN1000 4% Gel or Vehicle Gel. The subjects will apply the test material twice daily to their face after washing. Subjects will be seen daily at the skin study center during the week and will apply their evening and weekend dose at home. Cutaneous tolerability will be assessed by the Investigator at Baseline, Week 1, and Week 2. Safety assessments include collection of adverse events, laboratory results, and clinically significant changes in physical examination. P. acnes counts will be obtained at Baseline, Week 1 and Week 2.

Inclusion Criteria:

• Healthy adult male or female volunteers
• If a woman of child-bearing potential, agrees to use effective method of birth control during the study and for 30 days after the final study visit
• Agree to refrain from use of antimicrobial topical products during study

Exclusion Criteria:

• Any skin disorders of acute or chronic nature including psoriasis, eczema, etc
• Female subjects who are pregnant, nursing, or planning to become pregnant
• Subjects who have used topical or systemic antibiotics, estrogens, drugs associated with methemoglobinemia, nitrate donors
• Subjects with baseline methemoglobin > 2%
• Subjects with clinically significant anemia