PTCB Certified Pharmacy Technician (PTCE)MedicationsMedium
A pharmacy technician is asked to prepare a sterile ophthalmic solution. Which characteristic is MOST critical for this type of preparation to ensure patient safety and comfort?
- ASweet taste to improve palatability.
- BIsotonicity to match the osmotic pressure of tears.
- CPresence of a strong preservative to prevent microbial growth.
- DHigh viscosity to prolong ocular contact time.
Show answer & explanationAnswer & explanation
Correct answer: B. Isotonicity to match the osmotic pressure of tears.
Isotonicity is critical for ophthalmic solutions to prevent irritation, stinging, and damage to ocular tissues. Solutions that are significantly hypotonic or hypertonic can cause fluid shifts in the eye, leading to discomfort and potential tissue damage.
Why the other options are wrong
- A. Taste is irrelevant for an ophthalmic solution.
- C. Preservatives are important for multi-dose containers, but isotonicity is a fundamental characteristic for all ophthalmic solutions, even single-dose, to prevent immediate tissue damage.
- D. While some ophthalmic preparations are viscous, high viscosity is not the MOST critical characteristic for all ophthalmic solutions; it can sometimes cause blurring.
Ophthalmic Solution Isotonicity
The property of an ophthalmic solution having an osmotic pressure equivalent to that of human tears, typically corresponding to 0.9% sodium chloride solution.
- Crucial for patient comfort and to prevent irritation or damage to eye tissues.
- Solutions that are not isotonic can cause stinging, burning, and fluid shifts.
- Adjusting tonicity is a key step in formulating ophthalmic preparations.
Memory trick: For 'Eye Drops', think 'Clear', 'Sterile', and 'Balanced' like a tear.