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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Investigation to assess whether Mi-Gel applied to the vulvar vestibule results in a reduction in pain on daily life compared to a placebo
Scientific title
Randomised, double-blind, placebo-controlled, cross-over trial assessing the efficacy of Mi-Gel in the treatment of women with pudendal neuralgia or vulvodynia
Secondary ID [1] 298717 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
pudendal neuralgia 313628 0
vulvodynia 313629 0
Condition category
Condition code
Renal and Urogenital 312059 312059 0 0
Other renal and urogenital disorders
Neurological 312252 312252 0 0
Other neurological disorders

Study type
Description of intervention(s) / exposure
the study investigational product is a gel called Mi-Gel. Mi-Gel is a combination of two registered active ingredients, amitriptyline and oestriol. Participants will be asked to apply 0.2ml of product twice a day to the vulvar vestibule. The study is placebo-controlled with the placebo looking and feeling like the investigational product, but does not have any active ingredients. Participants will use Mi-Gel for three months and the placebo for three months with a six week washout between the two treatment arms. This study is double-blinded. Adherence to the study gel will be done by weighing the gel before and after use.
Intervention code [1] 314976 0
Treatment: Drugs
Comparator / control treatment
The control treatment is the placebo which will look and feel like the investigational product. It is a cross-over study so participants will use the placebo and investigational product. The placebo consists of Pluronic F-127, lecithin and isopropyl palmitate.
Control group

Primary outcome [1] 320688 0
Impact of pain on daily life compared to the placebo assessed using the Pelvic Pain Impact Questionnaire.
Timepoint [1] 320688 0
three months after starting each treatment arm and three months after finishing the second treatment arm.
Secondary outcome [1] 372514 0
composite secondary outcomes are a change in the level of bladder, bowel and sexual function scores from the Australian Pelvic Floor Questionnaire
Timepoint [1] 372514 0
three months after starting each treatment arm and three months after finishing the second treatment arm.
Secondary outcome [2] 372515 0
change in psychological distress measured using the Kessler Psychological Distress Scale
Timepoint [2] 372515 0
three months after starting each treatment arm and three months after finishing the second treatment arm.
Secondary outcome [3] 372516 0
Adverse events will be assessed by the investigators following clinical examination, medical record review and participant consultation.
Adverse events will be reported according to: NHMRC Guidance ‘Safety monitoring and reporting in clinical trials involving therapeutic goods (EH59)’ (November 2016)
Potential adverse events that have been highlighted include vaginal thrush, drowsiness, dry mouth, breast tenderness, constipation, fluid retention, nausea, post menopausal spotting, cervical discharge and flu-like symptoms. These risks are mild and uncommon (occurring less than 1% of the time). Headaches may occur which could be moderately uncomfortable but are also uncommon. Other, less common (occurring less than 1% of the time) side effects which are reported when using much higher doses of amitriptyline (one of the active ingredients in Mi-Gel) are classed as mild and include, sedation, tinnitus and blurring of vision.
Timepoint [3] 372516 0
measured every time the participant returns to the clinic which is visit 2 (10 days after randomisation), 3 (90 days after randomisation), 6 (142 days after randomisation), 7 (222 days after randomisation) and 8 (312 days after randomisation)
Secondary outcome [4] 372517 0
systemic estriol levels measured using a blood test
Timepoint [4] 372517 0
blood will be taken to measure estriol levels at baseline, then 10 days later at visit 2 and 142 days later at visit 6.

Key inclusion criteria
1. Female
2. Aged 18 or over
3. Pain duration of at least 3 months
4. Clinical diagnosis of Pudendal Neuralgia (Nantes Criteria) or
5. Clinical diagnosis of Vulvodynia
Minimum age
18 Years
Maximum age
No limit
Can healthy volunteers participate?
Key exclusion criteria
1. Aged less than 18
2. Current use of amitriptyline or oestriol (topical or oral)
(Patients would be suitable for inclusion after a wash out period
of six weeks)
3. Pudendal Nerve Block procedure within the last three months or
planning on having a Pudendal Nerve Block procedure during the
course of the trial
4. Known allergy to amitriptyline or oestriol
5. Contraindication to use of amitriptyline or oestriol
6. Pregnant or unwilling to use methods to avoid potential
pregnancy, as determined by a urine pregnancy test
7. Other vulvovaginal disorders including current acute/chronic
candidiasis or active DIV/psoriasis/lichen sclerosis
8. Endometrial hyperplasia or undiagnosed genital bleeding
9. Previous myocardial infarction, thrombosis, breast cancer,
cancer of any sexual organs, liver disease and/or porphyria
10. The investigator believes the candidate would not make a good
clinical trial patient

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation was concealment and was carried out using central randomisation by a computer.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
randomised 1:1 ratio using sequence randomisation in block groups of 10. Stratified for condition (either pudendal neuralgia and vulvodynia). This will be conducted using the randomisation software.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 3
Type of endpoint(s)
Statistical methods / analysis
Total sample size will be 52 after consideration of dropout rate of 20%.
The sample size calculation was conducted in PASS 16 Power Analysis and Sample Size Software (2018). NCSS, LLC. Kaysville, Utah, USA,

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 14215 0
Women’s Health and Research Institute of Australia - Sydney
Recruitment postcode(s) [1] 27197 0
2000 - Sydney

Funding & Sponsors
Funding source category [1] 303270 0
Commercial sector/Industry
Name [1] 303270 0
Women's Health & Research Institute of Australia
Address [1] 303270 0
Level 12
97-99 Bathurst St
Sydney NSW 2000
Country [1] 303270 0
Primary sponsor type
Commercial sector/Industry
Women's Health & Research Institute of Australia
Level 12
97-99 Bathurst St
Sydney NSW 2000
Secondary sponsor category [1] 303282 0
Name [1] 303282 0
Address [1] 303282 0
Country [1] 303282 0

Ethics approval
Ethics application status
Ethics committee name [1] 303808 0
Ethics committee address [1] 303808 0
123 Glen Osmond Rd
Eastwood SA 5063
Ethics committee country [1] 303808 0
Date submitted for ethics approval [1] 303808 0
Approval date [1] 303808 0
Ethics approval number [1] 303808 0

Brief summary
A randomised, cross-over study to determine if the application of Mi-Gel to the vulvar vestibule results in reduced impact of pain on daily life compared to placebo.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 94882 0
Dr Karen Chan
Address 94882 0
Women's Health & Research Institute of Australia
Level 12
97-99 Bathurst St
Sydney NSW 2000
Country 94882 0
Phone 94882 0
+61 2 8197 4400
Fax 94882 0
+61 2 8021 1244
Email 94882 0
Contact person for public queries
Name 94883 0
Mr Lachlan Porter
Address 94883 0
Mobius Medical
Suite 401
275 Alfred St
North Sydney NSW 2060
Country 94883 0
Phone 94883 0
+61 2 8317 5460
Fax 94883 0
+61 2 8317 5461
Email 94883 0
Contact person for scientific queries
Name 94884 0
Prof Thierry Vanciallie
Address 94884 0
Women's Health & Research Institute of Australia
Level 12
97-99 Bathurst St
Sydney NSW 2000
Country 94884 0
Phone 94884 0
+61 1300 722 206
Fax 94884 0
+61 2 8021 1244
Email 94884 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
There are no plans for individual participant data to be made available at the completion of the trial. Data sets may be distributed if a request is made in writing to WHRIA.
What supporting documents are/will be available?
No other documents available
Summary results
No Results