PTCB Certified Pharmacy Technician (PTCE)MedicationsMedium
A pharmacy technician is preparing a non-sterile oral solution. The master formula calls for 'Purified Water, USP'. Which of the following is the primary characteristic of Purified Water, USP, that makes it suitable for this purpose?
- AIt is suitable for intravenous administration without further treatment.
- BIt contains added electrolytes to maintain isotonicity.
- CIt is sterile and free of all microorganisms.
- DIt has been treated to remove most chemical impurities and ions.
Show answer & explanationAnswer & explanation
Correct answer: D. It has been treated to remove most chemical impurities and ions.
Purified Water, USP, is water that has been treated by distillation, ion exchange, reverse osmosis, or other suitable processes to remove most chemical impurities and ions. While it is microbiologically controlled, it is not necessarily sterile and is not suitable for parenteral administration unless further processed. Its primary characteristic for non-sterile oral solutions is its high chemical purity.
Why the other options are wrong
- A. Purified Water, USP, is not suitable for intravenous administration (parenteral use) without further processing and sterilization to become 'Sterile Water for Injection, USP' or similar products.
- B. Purified Water, USP, is typically hypotonic; it does not contain added electrolytes to maintain isotonicity, which is usually a characteristic of sterile water for injection or physiological saline.
- C. Purified Water, USP, is not required to be sterile; it only has limits on microbial content, making it unsuitable for sterile preparations unless sterilized.
Purified Water, USP
Water that has been processed to remove chemical impurities and ions, making it suitable for compounding non-sterile preparations and for use in pharmaceutical analyses.
- Not necessarily sterile; has microbial limits, but not zero.
- Achieved by distillation, ion exchange, or reverse osmosis.
- Not for parenteral (IV) administration without further treatment.
Memory trick: Water for drugs, purity matters, different types for tasks.