Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Alan Wade


Contact details

CPS Research
3 Todd Campus
West of Scotland Science Park
G20 0XA
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A multicentre, randomised, double blind, placebo-controlled, parallel group, single dose study of the efficacy of two flavour variants of Strepsils throat lozenges in the relief of sore throat due to upper respiratory tract infection


Study hypothesis

Do Strepsils lozenges improve sore throat symptoms over 2 hours?

Ethics approval

Fife, Forth Valley and Tayside Research Ethics Service approved on the 15th December 2008 (ref: FB/08/S0501/91)

Study design

Randomised single dose placebo controlled parallel group design

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

GP practices

Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Sore throat


1. Strepsils lozenge (0.6 mg 2,4-dichlorobenzylalcohol, 1.2 mg amylmetacresol) single dose, oral
2. Placebo lozenge, single dose, oral

This trial is of a single dose with a 2 hour follow up only.

Intervention type



Not Applicable

Drug names

Strepsils throat lozenges

Primary outcome measure

Area under the change from baseline curve (AUC) in severity of throat soreness, from 0 to 2 hours (using 11 point categorical throat soreness scale)

Secondary outcome measures

1. Change from baseline in severity of throat soreness (using the 11 point throat soreness scale) at 1,5, 10, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-dose
2. Onset of analgesia defined as time to first reporting 'moderate pain relief' (which is the midpoint on the 7 point sore throat relief scale)
3. Total sum of pain relief ratings: defined as the AUC from baseline to 2 hours post first dosing for sore throat relief
4. Sore throat relief at 1, 5, 10, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-dose
5. AUC from baseline to 2 hours for the change from baseline in difficulty swallowing
6. Change from baseline in difficulty in swallowing at 1, 5, 10, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-dose
7. AUC for throat numbness measurements from 1 to 120 minutes
8. Throat numbness at 1, 5, 10, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-dose
9. Overall treatment rating at 2 hours
10. Responses to the questions from the consumer questionnaire

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged greater than or equal to 16 to less than or equal to 75 years
2. Male and female patients
3. Primary diagnosis: patients with sore throat of onset within the past 4 days (i.e. less than or equal to 4 days) due to upper respiratory tract infection (URTI)
4. Patients who had a sore throat (greater than or equal to 6) on the Throat Soreness Scale at baseline
5. Objective findings that confirm the presence of tonsillopharyngitis (greater than or equal to 3 points on the expanded 21-point Tonsillopharyngitis Assessment)
6. Patients who gave written informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Any previous history of allergy or known intolerance to the study drug or the following formulation constituents: amylmetacresol (AMC), 2,4-dichlorobenzyl alcohol (DCBA), anise oil, peppermint oil, natural menthol, menthol synthetic, xylitol, mint, eucalyptus oil, liquid sucrose, liquid glucose, tartaric acid gran 571 GDE, ponceau 4R, edicol E124, carmoisine edicol E122, sugar, cream, anthocyanin, ginger, wasabi, blackcurrant and plum
2. Those whose sore throat had been present for more than 4 days
3. Those who had evidence of mouth breathing
4. Those who had evidence of severe coughing
5. Those who had any disease that could compromise breathing, e.g., bronchopneumonia
6. Those who had taken any medicated confectionary, throat pastille, spray, or any product with demulcent properties such as boiled sweets in the previous two hours
7. Those who had used any sore throat medication containing a local anaesthetic within the past 4 hours
8. Those who had used any analgesic, antipyretic or cold medication (e.g., decongestant, antihistamine, antitussive or throat lozenge) within the previous 8 hours
9. Those who have used a longer acting or slow release analgesic during the previous 24 hours, e.g., piroxicam and naproxen
10. Those taking antibiotics during the previous 14 days
11. Those with any painful condition that may have distracted attention from sore throat pain, e.g., mouth ulcers, etc.
12. Those with a history of severe renal impairment
13. Those with a history of severe hepatic impairment
14. Those with a history of alcohol abuse or who stated that they regularly consume alcohol in excess of the recommended amounts (excessive alcohol greater than 21 units per week for females and greater than 28 units per week for males)
15. Those unable to refrain from smoking during their stay in the investigative site
16. Women of childbearing potential, who reported they were pregnant or lactating, seeking pregnancy or failing to take adequate contraceptive precautions (i.e., an oral or injectable contraceptive, an approved hormonal implant or topical patch or an intrauterine device). Adequate contraception should also include abstinence, barrier contraception and partner vasectomy. A women of childbearing potential was defined as any female who is less than 2 years post-menopausal or has not undergone an hysterectomy or surgical sterilisation, e.g. bilateral tubal ligation, bilateral ovariectomy (oophorectomy).
17. Those previously randomised into the study
18. Those who have participated in a clinical trial in the previous 30 days. Thirty days were calculated from time of last dosing in the prior trial to time of anticipated dosing in this trial.
19. Those unable in the opinion of the investigator to comply fully with the study requirements, e.g., such as those who could not comprehend or correctly use the pain rating scales

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

CPS Research
G20 0XA
United Kingdom

Sponsor information


Reckitt Benckiser Healthcare (UK)

Sponsor details

Dansom Lane
United Kingdom

Sponsor type




Funder type


Funder name

Reckitt Benckiser Healthcare (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 results in:

Publication citations

  1. Results

    Wade AG, Morris C, Shephard A, Crawford GM, Goulder MA, A multicentre, randomised, double-blind, single-dose study assessing the efficacy of AMC/DCBA Warm lozenge or AMC/DCBA Cool lozenge in the relief of acute sore throat., BMC Fam Pract, 2011, 12, 6, doi: 10.1186/1471-2296-12-6.

Additional files

Editorial Notes