Question

Preservatives are usually not added to

• A. Small volume parenterals
• B. Large volume parenterals
• C. All parenterals
• D. Bacteriostatic water for injection

Answer 1

The Correct Option is B

To determine the correct answer, let's analyze the options and understand why preservatives are typically not added to large volume parenterals.

Parenterals are sterile drugs given via injection or infusion. They are divided into two main types based on volume: small volume parenterals (SVP) and large volume parenterals (LVP). 

1. Small Volume Parenterals (SVP): These are typically used for medications that are administered in doses of 100 mL or less. Preservatives may be added to SVPs to prolong shelf life and prevent microbial growth. Hence, this is not the correct option.
2. Large Volume Parenterals (LVP): These are intravenous solutions of more than 100 mL (e.g., >250 mL), used often for hydration and electrolyte balance or as a vehicle for drugs. Preservatives are generally not added to LVPs because they are usually administered in large quantities, which could lead to toxicity if preservatives are present. Additionally, LVPs often require safe and immediate administration, reducing the necessity of preservatives. Thus, this is the correct answer.
3. All parenterals: This option is incorrect because preservatives can be added to SVPs as described above.
4. Bacteriostatic Water for Injection: This type of water is specifically used for diluting or dissolving medications for injection and usually contains antimicrobials (or preservatives) to prevent bacterial growth. Therefore, this option is incorrect.

Conclusion: Preservatives are usually not added to large volume parenterals due to potential toxicity and their usage in large doses.