Amlex 5% Oral Paste (Amlexanox) – ACI Limited

1. About Amlex 5% Oral Paste (Amlexanox)

Amlex 5% Oral Paste contains Amlexanox 5%, a topical anti-inflammatory and antiallergic agent for use on oral mucosal surfaces, manufactured by ACI Limited, Bangladesh. Amlexanox is specifically formulated as an oral paste for direct application to recurrent aphthous ulcers — commonly known as canker sores — the most frequent cause of painful oral ulceration worldwide.

Recurrent aphthous ulcers (RAU) affect 15–25% of the general population. They appear as round or oval, shallow ulcers with a white or yellow centre and a red inflamed border, typically on the inner cheeks, lips, tongue, or floor of the mouth. They are painful, impair eating and speaking, and typically heal in 7–14 days without treatment. Amlex 5% significantly reduces ulcer pain and healing time through dual anti-inflammatory action on mast cells and T-lymphocytes.

2. Mechanism of Action

Amlexanox exerts its therapeutic effect through multiple pathways at the site of the aphthous ulcer:

• Mast cell stabilisation and mediator inhibition: Amlexanox inhibits the release of histamine, leukotrienes (LTC4, LTD4), and other inflammatory mediators from mast cells. These mediators drive the intense local inflammation, swelling, and pain characteristic of aphthous ulcers.
• Inhibition of Slow Reacting Substances of Anaphylaxis (SRS-A): Amlexanox suppresses SRS-A release — a key component of the allergic and inflammatory cascade at the ulcer site.
• Inhibition of T-lymphocyte and neutrophil migration: Reduces infiltration of inflammatory cells into the ulcer tissue, dampening local immune overactivation.
• Inhibition of 5-lipoxygenase and phosphodiesterase: These enzymatic pathways contribute to the production of prostaglandins and leukotrienes — amlexanox's inhibition of both further reduces the inflammatory milieu.

This combination of mechanisms accelerates the resolution of the immune-mediated inflammation at the base of the aphthous ulcer, resulting in faster healing and prompt pain reduction when applied early in the ulcer's development.

3. Indications

Amlex 5% Oral Paste (Amlexanox) is indicated for:

• Recurrent Aphthous Ulcers (Canker Sores) — Minor Form: The primary indication. Effective for minor aphthous ulcers (<1 cm diameter) on the non-keratinised oral mucosa (buccal mucosa, labial mucosa, tongue, soft palate, floor of mouth). Reduces pain intensity and shortens healing time when applied at first sign of ulcer development.
• Recurrent Aphthous Ulcers — Major Form: May be used as an adjunct for larger (major) aphthous ulcers, though systemic therapy is often also required for major/herpetiform types.
• Aphthous stomatitis associated with inflammatory bowel disease (IBD): Oral ulcers are a common extraintestinal manifestation of Crohn's disease and ulcerative colitis — amlexanox provides symptomatic local relief.

4. Dosage and Administration

Standard dosing for aphthous ulcers:

• Apply a small amount (approximately 0.5 cm ribbon) of Amlex 5% paste directly to each ulcer
• Apply 4 times daily — after breakfast, after lunch, after dinner, and at bedtime
• Continue until the ulcer has completely healed — usually 3–7 days
• Begin treatment as early as possible — ideally at the prodromal stage (tingling/burning sensation before ulcer forms) for best results

How to apply correctly:

1. Rinse mouth and dry ulcer area gently with clean gauze or tissue
2. Apply a small dab of paste directly onto the ulcer with a clean fingertip
3. Allow paste to adhere — do not eat or drink for at least 30 minutes after application
4. After bedtime application, avoid eating until morning

Children: Safety and efficacy in children under 12 not established — use only under medical supervision.

Elderly: No dose adjustment required.

5. Contraindications

• Known hypersensitivity to amlexanox or any paste excipients
• Use on infected ulcers — bacterial, viral (herpes), or fungal oral ulcers should be properly diagnosed and treated — amlexanox is not antibacterial or antiviral
• Traumatic or nutritional deficiency-related ulcers without appropriate management of the underlying cause

6. Warnings and Precautions

Correct diagnosis is essential: Not all oral ulcers are simple aphthous ulcers. Ulcers that are atypical, persist beyond 3 weeks, are rapidly enlarging, associated with lymphadenopathy, or appear in patients over 40 years old require urgent specialist evaluation to exclude oral malignancy.

For external use on oral mucosa only: Do not swallow in large amounts. Keep out of eyes. If eye contact occurs, rinse thoroughly with water.

Avoid in immunocompromised patients without diagnosis: Patients with HIV, diabetes, or on immunosuppressants are more susceptible to oral candidiasis and herpetic ulcers — these must be excluded before using amlexanox.

Diabetic patients: Amlexanox has no direct effect on blood glucose. However, diabetic patients have a higher frequency of recurrent aphthous ulcers, particularly when blood sugar control is suboptimal — good glycaemic control is important for reducing ulcer recurrence. Poorly controlled diabetes also impairs mucosal wound healing.

Pregnancy and lactation: Limited data available. Use only if clearly needed and under medical supervision.

7. Side Effects

Common:

• Transient stinging or burning sensation immediately after application (common, usually subsides within 1–2 minutes)
• Mild contact sensitivity at application site

Uncommon:

• Nausea if significant amounts are accidentally swallowed
• Diarrhoea (with swallowing)
• Allergic contact mucositis (rare)

Serious/rare:

• Hypersensitivity reactions — discontinue if rash, swelling, or systemic allergic reaction occurs

8. Drug Interactions

Topical oral amlexanox has minimal systemic absorption and therefore very limited drug interaction potential. No clinically significant interactions have been identified. Standard oral hygiene products (mouthwashes, toothpaste) do not interfere, but rinsing or eating immediately after application will remove the paste from the ulcer — maintain the 30-minute post-application window.

9. Pharmacokinetics

Absorption: Topical application to oral mucosa results in low but measurable systemic absorption, particularly from ulcerated surfaces. Bioavailability via oral mucosa is low (~17% from ulcerated sites).

Distribution: Limited data on distribution. Tissue penetration at the ulcer site is the primary therapeutic requirement.

Metabolism: Hepatically metabolised; active metabolite present in urine.

Elimination: Excreted in urine and faeces. Terminal half-life of systemically absorbed fraction approximately 3.5 hours. For topical oral use, systemic exposure is minimal and not clinically relevant.

10. Clinical Evidence for Amlexanox in Aphthous Ulcers

Multiple randomised controlled trials have established the efficacy of amlexanox 5% paste for recurrent aphthous ulcers:

• Pain reduction: Significantly greater pain reduction versus placebo from day 3 of treatment, with clinical benefit felt by most patients within 24–48 hours of first application
• Healing time: Reduces mean healing time from ~10 days (untreated) to ~6–7 days
• Ulcer size reduction: Treated ulcers show significantly faster reduction in diameter compared to placebo
• Prodromal use: Early initiation at the prodromal stage (before ulcer fully forms) shows the greatest benefit — some ulcers may be aborted entirely
• Recurrence: Does not directly prevent new ulcers but reduces the severity and duration when applied promptly

11. Aphthous Ulcers and Diabetes — Clinical Context

Recurrent aphthous ulcers are more prevalent and more severe in patients with diabetes mellitus:

• Hyperglycaemia impairs immune regulation and wound healing, extending ulcer duration
• Diabetic patients with autonomic neuropathy may have reduced salivary flow (xerostomia), creating a more ulcer-prone oral environment
• Oral infections including candidiasis (which can present as oral ulceration) are more common in diabetics — important to differentiate from simple aphthous ulcers
• Iron, vitamin B12, and folate deficiencies — common comorbidities of diabetes — also predispose to aphthous ulcers

Amlex 5% provides effective topical relief for aphthous ulcers in diabetic patients. Improving glycaemic control reduces the frequency and severity of recurrences.

12. ACI Limited — Quality Oral Care

Amlex 5% Oral Paste is manufactured by ACI Limited, one of Bangladesh's leading pharmaceutical companies with over 50 years of manufacturing excellence. ACI Limited follows WHO-GMP standards in formulation and quality control, ensuring that Amlex 5% delivers consistent drug content and optimal paste adhesion to mucosal surfaces. ACI's pharmaceutical portfolio covers a wide range of therapeutic categories including anti-infectives, cardiovascular medicines, CNS agents, and oral care products for the Bangladesh market.

13. Storage

• Store below 30°C in a cool, dry place
• Keep away from direct heat and sunlight — high temperature can alter paste consistency
• Keep the cap firmly closed after each use
• Keep out of reach of children
• Do not use after expiry date printed on the tube

Frequently Asked Questions (FAQ)

Q1: What does Amlex 5% (Amlexanox) treat?

Amlex 5% Oral Paste is used to treat recurrent aphthous ulcers — commonly called canker sores — which are painful shallow ulcers that appear inside the mouth on the cheeks, lips, tongue, or soft palate. These are not contagious (unlike cold sores caused by herpes simplex virus). When applied 4 times daily directly to the ulcer, Amlex 5% reduces pain, inflammation, and healing time through its anti-inflammatory and antiallergic action on mast cells and inflammatory mediators.

Q2: When should I start using Amlex 5% for the best results?

The best time to start Amlex 5% is as early as possible — ideally at the prodromal stage, which is the tingling, burning, or stinging sensation you feel in the mouth 1–2 days before the ulcer fully appears. Applying amlexanox at this stage can sometimes prevent the ulcer from fully forming or significantly reduce its size and severity. If the ulcer has already appeared, start treatment immediately — earlier treatment leads to faster pain relief and healing.

Q3: Does Amlex 5% prevent canker sores from coming back?

Amlex 5% treats existing aphthous ulcers but does not prevent new ones. Recurrent aphthous ulcers have multiple triggers including stress, minor trauma (biting cheek), certain foods (citrus, spicy foods), hormonal changes, nutritional deficiencies (iron, B12, folate), and immune system conditions. To reduce recurrence: address nutritional deficiencies, manage stress, avoid known trigger foods, and maintain good oral hygiene. Patients with diabetes should optimise blood glucose control, as poor glycaemic control increases ulcer frequency and severity.

Q4: Can I use Amlex 5% for any type of mouth ulcer?

Amlex 5% is specifically for aphthous ulcers (canker sores). It is not effective for: herpetic ulcers (cold sores caused by herpes simplex virus — require antiviral treatment), candidal infections (thrush — require antifungal), traumatic ulcers (sharp teeth or dentures — remove the cause), or ulcers from nutritional deficiency or systemic disease. If mouth ulcers are large, persist beyond 3 weeks, are associated with fever or swollen lymph nodes, or keep recurring frequently — consult a doctor to rule out underlying conditions including oral cancer.