The purpose of this study is to determine if topical application of a hydrogel that contains plant extracts will improve healing of diabetic foot ulcers when compared to treatment with a hydrogel alone.

This is a multi center, double-blind, randomized, placebo-controlled trial. A total of 80 patients will be randomized according to a 1: 1 randomization schedule. To participate in the trial, patients must have a current Diabetic Foot Ulcer (DFU) for between 60 days to 2 years at the screening visit. In the 2-week period between screening and baseline visit, the patient's DFU must not have healed by 30% or more, in wound area, while being treated with SWT twice a week during this screening period.

During the treatment period of 4 weeks all patients will be examined on a weekly basis by the site staff. Treatment with SWT plus the study gel (IZN-6D4 Gel or placebo gel) (including any necessary debridement) will be administered at these weekly visits. In addition, the patient or caregiver will be trained to perform SWT plus the study treatment at home once midweek between visits.

Inclusion Criteria:

• Current diagnosis of diabetes mellitus type 1 or 2
• Foot ulcer Wagner grade 1 or 2
• Ulcer between 1 square cm and 8 square cm present for at least 60 days and not more than two years
• HgbA1C less than 10%
• Able to comply with all procedures

Exclusion Criteria:

• Wound area decrease of greater than 30% between screening and baseline visits
• Gangrene on any part of the affected foot
• Pregnancy or lactation