Home » Trials » SLCTR/2022/004

Double-blind Randomized control trial of Ozone therapy for the treatment of chronic wounds


SLCTR Registration Number


Date of Registration

21 Mar 2022

The date of last modification

Mar 21, 2022

Application Summary

Scientific Title of Trial

Double-blind Randomized control trial of Ozone therapy for the treatment of chronic wounds

Public Title of Trial

Double- blind Randomized controlled trial comparing the efficacy of topical Ozone-Oxygen mixture therapy with sham procedure in the treatment of patients with chronic wounds..

Disease or Health Condition(s) Studied

Chronic wounds

Scientific Acronym


Public Acronym


Brief title


Universal Trial Number


Any other number(s) assigned to the trial and issuing authority


Trial Details

What is the research question being addressed?

Is topical Ozone therapy effective in healing of chronic wounds compared to sham procedure?

Type of study


Study design


Randomized controlled trial


Double blinded : Participants, Healthcare providers






Supportive care

Study Phase

Phase 3

Intervention(s) planned

The study setting includes the professorial surgical wards and surgical clinics of Teaching Hospital Anuradhapura. Participants will be patients aged 18 or over with chronic wounds, who have not received topical Ozone therapy previously.

Method of randomization includes a covariates adaptive randomization based on age and gender. The randomization will done via computer generated programme which takes in to account the above parameters.

Intervention: The EXT 120 Ozone Generator will be used to generate the ozone/oxygen mixture at differing concentrations as required. The wound will be cleaned initially with the ozonized water (produced by the EXT 120 Ozone generator). A bag will be placed over and around the chronic wound and the gas of Ozone/Oxygen mixture of differing concentrations generated by the Ozone generator will be used to fill the bag surrounding the chronic wound and continued for 30 minutes.

The ozone/oxygen mixture is initially applied at higher concentrations (96% oxygen and 4% (80 µg/ml) Ozone) three times a week until the wound size is reduced by 50% or a maximum of four weeks. Then the dose is decreased to a lower concentration (98% oxygen and 2% (40 µg/ml) Ozone) and applied twice a week for another 4 weeks. Finally, the ozone concentration will be reduced to 99% oxygen and 1% (20 µg/ml) Ozone and applied twice a week for another 4 weeks. The total period of intervention for a patient will be 12 weeks. Standard of care for chronic wounds consists of cleaning, dressing, and in some cases debridement of the wound. It further includes swabbing for identification of infection and use of antibiotics if indicated.

Control: The procedure for the control arm participants will be that the EXT 120 Ozone Generator is set to the inactive mode and room air delivered in the same manner. Treatment frequency will be the same. Control arm participants will also receive the standard wound care as usual.

Inclusion criteria

Males and females who are 18 years or older with chronic wounds (wounds that fail to proceed through the normal phases of wound healing in an orderly and timely manner).

Exclusion criteria

• Patients with known contraindication to ozone therapy • Any patient who had previously been treated with ozone or hyperbaric oxygen therapy, • A history of collagen disease, • Pregnant mothers. • Participants with cognitive impairment (patients with psychotic illnesses, learning disability).

Primary outcome(s)

  1. The wound healing effect at 4,8,12 weeks of treatment is determined by the wound condition, length, width, depth, surface area, ulcer area, healing progression, presence of infection, and the need for debridement. Ulcer area will be calculated from film transparency tracings using grid paper. The criterion of the therapeutic effect includes: Grade 0 – no change or worse than before Grade 1 – wound size reduced less than ½ of the original wound Grade 2 – wound size reduced more than ½, the secretion obviously less than before, there is little necrosis, fresh granulation generated Grade 3 – wound healing, completely epithelialized with dimensions at 0 ×0×0 cm. Proportion of patients in each category will be calculated.

At baseline and at the end of weeks 1, 2, 3, 4, 6, 8, 10, and 12.


Secondary outcome(s)

  1. Symptomatic improvement will be assessed by a questionnaire. Symptomatic improvement and improvement in quality of life will be assessed by a wound-specific questionnaire, the “wound -QoL -17 questionnaire”, containing17 items. Questions 1-4 involves symptoms due to the wound while others are on the psychological impact and limitation of daily activities. Each item is scored on a 5-point Likert scale from 0 (not at all) to 4 (very much). The mean scores will be compared.

At baseline and at the end of weeks 1, 2, 3, 4, 6, 8, 10, and 12.


Target number/sample size

80 (40 in a group)

Countries of recruitment

Sri Lanka

Anticipated start date


Anticipated end date


Date of first enrollment

Date of study completion

Recruitment status


Funding source

Integrated Palliative Care Research Centre

Regulatory approvals

State of Ethics Review Approval



Date of Approval


Approval number


Details of Ethics Review Committee

Name: Faculty of Medicine and Allied Sciences, Rajarata University
Institutional Address:Faculty of Medicine and Allied Sciences, Rajarata University 50008 Anuradhapura-Saliyapura, Anuradhapura, Sr Lanka.
Telephone:+94 (0)25 2053633
Email: ethicsreviewcommittee@gmail.com

Contact & Sponsor Information

Contact person for Scientific Queries/Principal Investigator

Dr.Senaka Pilapitiya
Senior Lecturer
Faculty of Medicine and Allied science Rajarata University



Contact Person for Public Queries

Dr. Sujeewa Priyantha Bandara Thalgaspitiya
Senior Lecturer
Department of Surgery Faculty of Medicine and Allied Sciences Rajarata University



Primary study sponsor/organization

Pilapitiya-Gnanam Palliative Care Trust, No 516, Sri Sangaraja Mawatha, Colombo 10.

Secondary study sponsor (If any)

Trial Completion details

Do the investigators plan to share identified individual clinical trial participant-level data (IPD)?


IPD sharing plan description

Study protocol available


Protocol version and date

Not Available

Protocol URL

Not Available

Results summary available


Date of posting results

Date of study completion

Final sample size

Date of first publication

Link to results

Brief summary of results