PTCB Certified Pharmacy Technician (PTCE)MedicationsMedium
A pharmacy technician is preparing a non-sterile compound that requires the use of Purified Water, USP. Which of the following statements correctly describes a characteristic of Purified Water, USP?
- AIt must be sterile and pyrogen-free.
- BIt contains added antimicrobial agents to prevent microbial growth.
- CIt is obtained by distillation, ion exchange, or reverse osmosis, and meets specific purity standards.
- DIt is suitable for injection without further processing.
Show answer & explanationAnswer & explanation
Correct answer: C. It is obtained by distillation, ion exchange, or reverse osmosis, and meets specific purity standards.
Purified Water, USP, is water that has been processed to remove most chemical contaminants, typically through distillation, ion exchange, or reverse osmosis. It meets specific purity standards for chemical contaminants but is NOT necessarily sterile or pyrogen-free, making it unsuitable for injection without further processing.
Why the other options are wrong
- A. This describes Water for Injection, USP, or Sterile Water for Injection, USP, not Purified Water, USP.
- B. Purified Water, USP, does not contain added antimicrobial agents.
- D. Purified Water, USP, is not suitable for injection; Water for Injection, USP, is required.
Purified Water, USP
A type of water meeting specific chemical purity standards set by the United States Pharmacopeia, used in non-sterile compounding and for preparing other USP waters.
- Obtained by distillation, ion exchange, reverse osmosis.
- Reduced chemical contaminants.
- Not necessarily sterile or pyrogen-free; unsuitable for injection.
Memory trick: USP Waters: Purity for Purpose