The pH of Water for Injection (WFI) is specified to be within the range of 5.0 to 7.0, according to compendial standards.
Understanding WFI and pH
Water for Injection (WFI) is a highly purified form of water used extensively in the pharmaceutical and biotechnology industries. It is a critical component in injectable medications and is subject to stringent quality control measures. The pH of WFI is a vital parameter that needs to be controlled because it can affect the stability and efficacy of pharmaceutical products. A pH that is outside of this range might make the product unstable, lead to degradation, or negatively affect the patient.
Compendial Standards for WFI
The quality of WFI is regulated by pharmacopeial standards, ensuring its suitability for pharmaceutical use. According to the provided reference from AQUA-CHEM, the following table summarizes some critical parameters for WFI:
| Parameter | Value |
|---|---|
| Bacterial Endotoxin | < 0.25 IU / ml |
| TOC | < 0.5 mg/l |
| pH | 5.0 – 7.0 |
| Nitrates | < 0.2 ppm |
This table emphasizes that the pH of WFI is specifically required to fall within the range of 5.0 to 7.0.
Why is pH Control Important?
- Product Stability: Maintaining the pH within the specified range is critical for the stability of pharmaceutical products.
- Efficacy: pH can affect the therapeutic properties of a drug and ensure that it works as intended.
- Patient Safety: Strict pH control ensures that injectable products do not cause adverse reactions due to improper pH levels.
- Compatibility: Proper pH control is essential for the compatibility of different ingredients within a pharmaceutical formulation.
Conclusion
The pH of WFI is a crucial parameter that is regulated to ensure product quality and patient safety. The range of 5.0 to 7.0 is strictly adhered to in the manufacturing and processing of WFI for pharmaceutical use.
