How to prepare cefoxitin sodium skin test solution
Dec 03, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
The preparation of cefoxitin sodium skin test solution should follow standardized procedures, generally including preparing the necessary equipment, calculating drug dosage, dissolving the drug stock solution, stepwise dilution of the solution, and confirming the final concentration of the skin test solution. Gather cefoxitin sodium powder, sterile normal saline, 1-mL and 5-mL syringes, sterile swabs, and disinfectant alcohol. Check the packaging of all equipment to ensure there is no damage or expiration, and arrange items according to aseptic technique.
The preparation of cefoxitin sodium skin test solution must follow standardized procedures, generally involving the preparation of required equipment, calculation of drug dosage, dissolution of the drug stock solution, stepwise dilution of the solution, and confirmation of the final skin test concentration. A detailed analysis is as follows:
1. Prepare necessary equipment: Gather cefoxitin sodium powder, sterile normal saline, 1 mL and 5 mL syringes, sterile cotton swabs, and disinfectant alcohol. Check all packaging to ensure there are no damages or expired items, and arrange the equipment aseptically to prevent contamination.
2. Calculate drug dosage: Determine the initial dosage based on the drug specification and calculate the required amount according to standard skin test concentration requirements. For example, with a common 1 g vial, the drug should be dissolved and then gradually diluted to the specified concentration to ensure precise dosing and avoid affecting test results.
3. Dissolve the drug stock solution: Add 4 mL of sterile normal saline to 1 g of the drug. Slowly inject the saline into the vial and gently shake until the powder is completely dissolved. Avoid vigorous shaking to prevent foam formation, which may affect subsequent dilutions and dosage accuracy.
4. Stepwise dilution of the solution: Draw 0.1 mL of the stock solution and dilute it with saline to 1 mL. Mix thoroughly, then take 0.1 mL of this solution and dilute again to 1 mL. Repeat this process until the required concentration is achieved. After each dilution, ensure thorough mixing to maintain uniform concentration.
5. Confirm skin test solution concentration: Verify that the final concentration meets the standard of 300 micrograms/mL and inspect the solution for clarity and absence of particulate matter. Once confirmed, store the solution in a sterile environment until use. Avoid prolonged storage, which may lead to degradation or contamination.
Preparation must be performed by trained healthcare professionals following strict aseptic techniques and dosage standards. The solution should be used within the recommended time frame; otherwise, it must be re-prepared. If any abnormalities such as cloudiness occur, discard the solution immediately and prepare a new batch to ensure patient safety.
