Safety Study of Topical Doxycycline Gel for Adult Diabetic Lower Extremity Ulcers

Inclusion Criteria: * Have a documented history of type I or type II diabetes mellitus as defined by the American Diabetes Association * Women of childbearing potential must have a negative urine pregnancy test at screening and at baseline, and: • Agree to use a double-barrier method of contraception during their participation in this study; * condoms (with spermicide) and hormonal contraceptives OR * condoms (with spermicide) and intrauterine device OR * intrauterine device and hormonal contraceptives OR * Abstains from sexual intercourse during their participation in this study OR * Is with a same-sex partner and does not participate in bisexual activities where there is a risk of becoming pregnant * Have an ulcer on the lower extremity (distal to a line connecting the medial and lateral malleoli) that has been present for at least 3 weeks and that is 1.2 cm2 to 4.0 cm2 at initial screening * Be able to apply study drug to their ulcer, or have a caregiver do it * Adequate blood flow to target ulcer extremity as measured by transcutaneous oxygen tension (TcpO2) of \>30mmHg * Target ulcer is Grade I according to the Wagner Grading Scale * Quantitative bacterial count of of \< 1.0 x 1.0E5 per gram of tissue for non-infected ulcers * Quantitative bacterial count of ≥ 1.0 x 1.0E5 per gram of tissue for infected ulcers Exclusion Criteria: * Be a pregnant or lactating woman or a female of childbearing potential who is not practicing acceptable form of birth control. * Allergy to tetracycline, minocycline, demeclocycline, or any other known tetracycline derivative * Have more than three chronic ulcers present at baseline * Have undergone treatment with system corticosteroid or immunosuppressive therapy in the past 2 months * Have connective tissue disease * Currently be going through kidney dialysis for renal failure * Have undergone treatment with doxycycline, Procuren®, or Regranex® within the last 30 days * Have participated in another clinical research trial within the last 30 days * Have a known history of osteomyelitis affecting to the area where the target ulcer is present * Have any other concomitant condition which, in the opinion of the investigator, would make the subject unsuitable for the study. * Subject has ulcers resulting from any cause other than diabetes (electrical burn, arterial insufficiency, chemical or radiation insult)