1. Clinical Overview
Hydroxypropylmethylcellulose (HPMC) 0.3% w/v is a sterile, non-preserved, topical ophthalmic solution used as an ocular lubricant and protectant. It is a semisynthetic, inert, viscoelastic polymer derived from cellulose. In the Indian context, it is widely used as a first-line artificial tear substitute for managing dry eye disease (DED), which is highly prevalent due to environmental factors, screen time, and urban pollution. It acts by mimicking the mucin layer of the tear film, providing lubrication, moisture retention, and protection for the ocular surface.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon instillation. | Approximately 60 to 90 minutes per instillation, depending on the severity of ocular surface dryness. | Topical ophthalmic; systemic absorption is negligible. |
2. Mechanism of Action
HPMC is a mucoadhesive polymer with hydrophilic properties. When instilled into the eye, it increases the viscosity and retention time of the tear film. It binds to the mucin layer of the ocular surface, forming a protective, lubricating layer that stabilizes the precorneal tear film, reduces friction during blinking, and protects epithelial cells from desiccation. Its high molecular weight and pseudoplastic nature provide comfort without causing significant blurring of vision.
3. Indications & Uses
- Dry Eye Disease (Keratoconjunctivitis Sicca) - Aqueous-deficient and Evaporative types
- Symptomatic relief of dry eye due to environmental factors (air conditioning, pollution, digital screen use)
- Lubrication and protection of the ocular surface
4. Dosage & Administration
Adult Dosage: One to two drops in the affected eye(s) as needed, typically 3 to 4 times daily or more frequently as directed by a physician. Can be used hourly in severe cases.
Administration: 1. Wash hands before use. 2. Tilt head back. 3. Gently pull down the lower eyelid to form a pouch. 4. Instill the prescribed number of drops into the pouch without touching the dropper tip to the eye, eyelid, or any surface. 5. Close eyes gently for 1-2 minutes. Apply gentle pressure to the nasolacrimal duct (inner corner of the eye) for a minute to minimize systemic drainage. 6. If using other eye drops, wait at least 5-10 minutes between applications. 7. For single-dose units, discard immediately after use.
5. Side Effects
Common side effects may include:
- Transient mild blurring of vision immediately after instillation
- Mild ocular discomfort or stinging upon application
- Sticky eyelashes upon drying
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Other topical ophthalmic medications (e.g., Glaucoma drops, Antibiotics, NSAIDs) | HPMC may delay the absorption of subsequently instilled drugs due to its viscosity and barrier effect. | Moderate |
| Eye ointments | May cause uneven mixing and reduced efficacy of both products. Administer drops at least 10 minutes before ointments. | Moderate |
7. Patient Counselling
- DO wash your hands before use.
- DO wait at least 5-10 minutes before using other eye drops.
- DO discard single-dose units immediately after one use.
- DO NOT touch the dropper tip to any surface to avoid contamination.
- DO NOT wear contact lenses while using unless the product is specifically labeled as suitable for use with lenses. Remove lenses before application and wait at least 15 minutes before reinsertion.
- DO NOT drive until transient blurring clears.
8. Toxicology & Storage
Overdose: Accidental ingestion of small amounts is unlikely to cause harm. Ocular overdose (excessive drops) may lead to excessive blurring of vision and sticky sensation. Rinse eye with clean water if discomfort occurs.
Storage: Store at room temperature (15°C to 25°C). Do not freeze. Keep the bottle tightly closed when not in use. Protect from light and excessive heat. Keep out of reach of children. For multidose bottles, do not use for more than 30 days after opening. Mark the date of opening on the bottle.