PTCB Certified Pharmacy Technician (PTCE)MedicationsHard
A pharmacy technician is preparing a sterile ophthalmic solution. Which characteristic is MOST critical for ensuring the safety and efficacy of this preparation?
- APleasant taste for patient compliance.
- BBright color for easy identification.
- CHigh viscosity for prolonged contact time.
- DIsotonicity with lacrimal fluid.
Show answer & explanationAnswer & explanation
Correct answer: D. Isotonicity with lacrimal fluid.
Ophthalmic solutions must be isotonic with the natural tears (lacrimal fluid) to prevent irritation, stinging, and damage to the eye's tissues. Significant deviations from isotonicity can cause discomfort and potentially harm the eye.
Why the other options are wrong
- A. Taste is irrelevant for ophthalmic solutions, as they are not ingested.
- B. Coloring is generally avoided in ophthalmic preparations unless specifically indicated for diagnostic purposes, as it can cause staining or irritation.
- C. While some ophthalmic preparations use viscosity enhancers, it's not the MOST critical factor for all solutions and can impact vision.
Ophthalmic Solution Characteristics
Sterile ophthalmic solutions must meet stringent requirements, including sterility, clarity, appropriate pH, and most critically, isotonicity, to ensure safety and comfort for direct application to the eye.
- Must be sterile to prevent eye infections.
- Must be free of visible particulate matter (clarity).
- pH should be close to physiological pH of tears (7.4).
- Isotonicity (osmotic pressure) close to tears (0.9% NaCl equivalent).
Memory trick: Eye drops need to be 'eye-friendly': sterile, clear, and balanced.