Evaluate the safety, side effects and maximum tolerable dose of topical application of Antimicrobial Peptides: Pexiganan (MSI-78), Tilapia piscidin 4 (TP4), Melittin, Nisin-A and Omiganan (MX-226) on the skin of healthy volunteers to the treatment of Skin and Soft Tissue Infections.

Evaluate the safety, side effects and maximum tolerable dose of 5 Antimicrobial Peptides (AMPs) on the skin of healthy volunteers to the treatment of Skin and Soft Tissue Infections.

Double-blind block randomized, vehicle-controlled, ascending doses clinical trial phase 1with 30 patients in 5 groups. Concealed randomization sequence carried out with sequentially numbered, sealed, opaque envelopes.

Initially, 30 healthy volunteers who have Inclusion criteria will be randomly divided into five groups of six. In each group, 4 intervention subjects will be treated with the topical single dose AMPs on their healthy skin and 2 control subjects will receive placebo. The intervention groups will receive 1/2, 1, 2, 3 and 4fold of the minimum inhibitory concentration (MIC) of peptides, respectively. During the study, safety, side effects and maximum tolerable dose of peptides will be examined. The place of study is in Imam Reza Hospital.

Inclusion criteria: Participant compliance with treatment method (Adherence) Having conditions for frequent visits to control the treatment method Informed consent to participate in the research project Non-smoker (no nicotine products for at least 3 months prior to screening) BMI ≥18 kg/m2 and ≤32.0 kg/m2 with a minimum weight of 50 kg Exclusion criteria: Use of any antibiotic and traditional drugs at least 7 days prior to screening Use of immunosuppressive drugs at least 14 days prior to screening Having any history of skin allergies

The intervention groups will be treated with different concentrations of AMPs and the control groups will receive a placebo.

The safety of local use of antimicrobial peptides, The maximum tolerable concentration of topical antimicrobial peptides

In the section on how to conduct the study, the duration of the treatment was 21 days with an interval of every 3 days. Considering that the main purpose of the first phase of a clinical trial is to check the safety of the investigational medicinal product in healthy people, not treatment and effectiveness, the subjects of the present study were not sick. Therefore, the duration of treatment is not considered. For this purpose, the design of a study in the field of measuring the time points of the primary outcome variable in the form of a single ascending dose on the skin of healthy people with the measurement time points at 30 and 60 minutes after the intervention (to assess immediate sensitivity) and at 24 and 72 The hour after the intervention (to assess delayed sensitivity), needs to be updated.

Randomization Method: Block randomization Randomization Unit: Block size of 6 Randomization Tool: Random number table using http://www.randomization.com Random sequence generation: Random number table Allocation concealment: Sequentially numbered, sealed, opaque envelopes

This study is designed as a double-blind. So that the participants, clinicians and evaluators will be unaware of intervention and control groups. In other words, participants, physicians, safety & side effect evaluators and laboratory personnel will not know which participant is taking the drug and which of them is taking the placebo. For this purpose, the drug/placebo will be placed in sequentially numbered, sealed, opaque envelopes and will be assigned to each participant with a random selection.