Sore ThroatEarly Phase 1DIFFLAMNCT06676748
Benzydamine Hydrochloride and Post-operative Sore Throat
A Early Phase 1 study testing Benzydamine Hydrochloride in people with Sore Throat and Postoperative Care, run by KK Women's and Children's Hospital at 1 site in Singapore.
Trial summary
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is prevalent and unappealing. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. Read more about this study
- Who is it for?
- Ages 21 to 80 years, women only
- Conditions the study is for
- Sore Throat, Postoperative Care
- What is being tested?
- Benzydamine Hydrochloride
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 106 participants
- Where
- 1 siteSingapore
- Study dates
- 11 Aug 2025to 31 Dec 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 80 years
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- American Society of Anaesthesiologists (ASA) physical status 1-2
- Female patients having laryngeal mask airway (LMA) for airway management for surgery in KKH;
- BMI < 40 kg/m2.
Who cannot join
- Pregnant;
- Pre-existing sore throat, or history of upper respiratory tract infection/ abnormalities, hypertension, chronic pain or anti-inflammatory drugs and antihypertensive treatment;
- Allergies to benzydamine hydrochloride;
- Symptomatic hiatus hernia;
- Severe gastroesophageal reflux disease;
- Contraindications to the use of LMA.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Singapore1 site, 1 recruiting
- Recruiting
KK Women's and Children's Hospital
Singapore
Ban Leong Sng, 65 6394 8436, sng.ban.leong@singhealth.com.sg
About this study
Official title: The Effect of Benzydamine Hydrochloride Spray on Post-operative Sore Throat: a Randomized Controlled Study
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is prevalent and unappealing. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. The Difflam Forte Anti-Inflammatory Throat Spray (Difflam) contains benzydamine hydrochloride, a non-steroidal anti-inflammatory agent with topical analgesic properties. This study will randomize 106 women undergoing gynaecological surgery under general anaesthesia with LMA use at KK Women's and Children's Hospital (KKH) in 1:1 allocation ratio of study (Difflam spray) and control (usual practice; no intervention) groups. Demographic and intraoperative airway data collection will be conducted in perioperative period. Those allocated to study group will receive Difflam spray when awake in the post-anaesthesia care unit (PACU). The primary aim to determine if patients undergoing general anaesthesia with LMA use with the Difflam spray in PACU will have a lower incidence of POST in the immediate and 4 hours postoperative recovery period, as compared with those in the control group. Other outcome measures include the severity of pain of sore throat as measured by the visual analog scale, and incidence of side effects associated with the Difflam spray. This proposal will determine whether the use of Difflam spray is suitable to be implemented in local clinical setting and improve perioperative care.
Read the detailed description
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is common, with reported incidences being as high as 40 - 60%. This is in spite of ongoing efforts to address this pertinent issue, including utilization of updated iterations of LMA devices, reduction of LMA cuff pressure, etc.. POST is an independent predictor of patient dissatisfaction following general anaesthesia and should be investigated further.
The cause of POST is multifactorial, with various mechanisms at play. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. While the application of topical lidocaine on airway mucosa after surgery for analgesic relief may seem to be a possible solution, this may however, increase the risk of aspiration due to diminished cough reflex and swallowing ability. On the other hand, mouth gargles with analgesics may not provide immediate relief for POST as they require much cooperation from the patient that proves to be challenging in the immediate postoperative period.
The Difflam Forte Anti-Inflammatory Throat Spray is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed. The effectiveness of benzydramine on alleviating sore throat has been well established in modern medicine. However, a spray formulation of this medication has not been utilized for this purpose yet. With the spray formulation, patient cooperation will not be required for effective delivery of BH medication - a critical factor in view of patient drowsiness post operation.
- Conditions
- Sore Throat, Postoperative Care
- Being tested
- Benzydamine Hydrochloride
- Keywords
- Sore throat, Posoperative care, benzydamine hydrochloride, laryngeal mask airway
- Medical subject headings
- Pharyngitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Benzydamine HydrochlorideDrug
Also called benzydamine hydrochloride 3 mg/mL, Difflam Forte Anti-Inflammatory Throat Spray
The Difflam Forte Anti-Inflammatory Throat Spray (iNova Pharmaceuticals Pte Ltd, Singapore) is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed.
| Study group | Role | What they receive |
|---|---|---|
| Study group | Experimental | Study group will receive Difflam spray by delivering 4 sprays to the posterior pharynx. Patients will be asked to swallow after each spray. Questionnaires will then be administered to the patients 10 minutes after administration of the intervention, and then 4 hours after for their pain scores and side effects, if any. Receives: Drug: Benzydamine Hydrochloride |
| Control group | No intervention | Patients will be asked to fill in questionnaires for their pain scores and side effects, if any. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative sore throat
Presence of postoperative sore throat (POST) during the immediate and 4 hours postoperative recovery period. At these two time points patients will be asked whether they have sore throat; and answering 'yes' will be considered as 'POST present'.
Measured: 1 day; from the immediate and 4 hours postoperative recovery period
Secondary outcomes (2)
Postoperative pain score
Pain score during the immediate and 4 hours postoperative recovery period after intervention (Visual analog scale 0-10) will be asked, with zero being no pain, and 10 being the worst pain possible.
Measured: 1 day; from the immediate and 4 hours postoperative recovery period
Side effects
Presence of side effects during the immediate and 4 hours postoperative recovery period. At these two time points patients will be asked whether they have burning and/or stinging, dry mouth, cough, local numbness; and answering 'yes' will be considered as 'burning and/or stinging, dry mouth, cough, local numbness present'.
Measured: 1 day; from the immediate and 4 hours postoperative recovery period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2024
- Study start11 Aug 2025
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sore ThroatStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The study uses a randomized (1:1 allocation ratio) and single-blinded trial design. Block randomization will be used to randomly assign patients to no intervention i.e., usual practice (Control) and BH (Difflam) spray (study) groups in a 1:1 allocation ratio based on a computer-generated code that will be prepared at a remote site and sealed in opaque, sequentially numbered envelopes.
- Masking
- None (open label)
- Enrolment
- 106 participants (estimated)
Sponsor and investigators
- Lead sponsor
- KK Women's and Children's Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Sng Ban Leong, KK Women's and Children's Hospital
- Investigators
- Ban Leong Sng, Principal investigator, KK Women's and Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06676748
- Sponsor's protocol ID
- 2021/2264
- Acronym
- DIFFLAM
- Status last verified
- Aug 2026
- First submitted
- 5 Nov 2024
- Last updated
- 6 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: To be shared upon request
Study at a glance
From the registry record, last updated by the sponsor on 6 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Benzydamine Hydrochloride Spray on Post-operative Sore Throat: a Randomized Controlled Study
- ClinicalTrials.gov ID
- NCT06676748
- Acronym / sponsor ID
- DIFFLAM / 2021/2264
- Conditions
- Sore Throat, Postoperative Care
- Keywords
- Sore throat, Posoperative care, benzydamine hydrochloride, laryngeal mask airway
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 106 participants (estimated)
- Lead sponsor
- KK Women's and Children's HospitalOther government
- Study start
- 11 Aug 2025 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 6 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is prevalent and unappealing. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. The Difflam Forte Anti-Inflammatory Throat Spray (Difflam) contains benzydamine hydrochloride, a non-steroidal anti-inflammatory agent with topical analgesic properties. This study will randomize 106 women undergoing gynaecological surgery under general anaesthesia with LMA use at KK Women's and Children's Hospital (KKH) in 1:1 allocation ratio of study (Difflam spray) and control (usual practice; no intervention) groups. Demographic and intraoperative airway data collection will be conducted in perioperative period. Those allocated to study group will receive Difflam spray when awake in the post-anaesthesia care unit (PACU). The primary aim to determine if patients undergoing general anaesthesia with LMA use with the Difflam spray in PACU will have a lower incidence of POST in the immediate and 4 hours postoperative recovery period, as compared with those in the control group. Other outcome measures include the severity of pain of sore throat as measured by the visual analog scale, and incidence of side effects associated with the Difflam spray. This proposal will determine whether the use of Difflam spray is suitable to be implemented in local clinical setting and improve perioperative care.
Detailed description
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is common, with reported incidences being as high as 40 - 60%. This is in spite of ongoing efforts to address this pertinent issue, including utilization of updated iterations of LMA devices, reduction of LMA cuff pressure, etc.. POST is an independent predictor of patient dissatisfaction following general anaesthesia and should be investigated further.
The cause of POST is multifactorial, with various mechanisms at play. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. While the application of topical lidocaine on airway mucosa after surgery for analgesic relief may seem to be a possible solution, this may however, increase the risk of aspiration due to diminished cough reflex and swallowing ability. On the other hand, mouth gargles with analgesics may not provide immediate relief for POST as they require much cooperation from the patient that proves to be challenging in the immediate postoperative period.
The Difflam Forte Anti-Inflammatory Throat Spray is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed. The effectiveness of benzydramine on alleviating sore throat has been well established in modern medicine. However, a spray formulation of this medication has not been utilized for this purpose yet. With the spray formulation, patient cooperation will not be required for effective delivery of BH medication - a critical factor in view of patient drowsiness post operation.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- The study uses a randomized (1:1 allocation ratio) and single-blinded trial design. Block randomization will be used to randomly assign patients to no intervention i.e., usual practice (Control) and BH (Difflam) spray (study) groups in a 1:1 allocation ratio based on a computer-generated code that will be prepared at a remote site and sealed in opaque, sequentially numbered envelopes.
| Arm | Type | Receives |
|---|---|---|
| Study group | Experimental | Drug: Benzydamine HydrochlorideStudy group will receive Difflam spray by delivering 4 sprays to the posterior pharynx. Patients will be asked to swallow after each spray. Questionnaires will then be administered to the patients 10 minutes after administration of the intervention, and then 4 hours after for their pain scores and side effects, if any. |
| Control group | No intervention | –Patients will be asked to fill in questionnaires for their pain scores and side effects, if any. |
Who may qualify
- Ages
- 21 to 80 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- American Society of Anaesthesiologists (ASA) physical status 1-2
- Female patients having laryngeal mask airway (LMA) for airway management for surgery in KKH;
- BMI < 40 kg/m2.
Key exclusion criteria (6 listed)
- Pregnant;
- Pre-existing sore throat, or history of upper respiratory tract infection/ abnormalities, hypertension, chronic pain or anti-inflammatory drugs and antihypertensive treatment;
- Allergies to benzydamine hydrochloride;
- Symptomatic hiatus hernia;
- Severe gastroesophageal reflux disease;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Benzydamine HydrochlorideAlso: benzydamine hydrochloride 3 mg/mL, Difflam Forte Anti-Inflammatory Throat SprayThe Difflam Forte Anti-Inflammatory Throat Spray (iNova Pharmaceuticals Pte Ltd, Singapore) is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed. | Drug | Study group |
Primary outcome
Postoperative sore throat
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Presence of postoperative sore throat (POST) during the immediate and 4 hours postoperative recovery period. At these two time points patients will be asked whether they have sore throat; and answering 'yes' will be considered as 'POST present'.
2 secondary outcomes
Postoperative pain score
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Side effects
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Aug 2026.
- Individual participant dataSharing planned: No. To be shared upon request
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ban Leong Sng principal investigator
KK Women's and Children's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Benzydamine Hydrochloride in people with Sore Throat and Postoperative Care, run by KK Women's and Children's Hospital at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ban Leong Sng (+65 6394 1077, sng.ban.leong@singhealth.com.sg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Postoperative sore throat (time frame: 1 day; from the immediate and 4 hours postoperative recovery period). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Aug 2026.