When to get tested if you suspect HIV infection
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 required 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 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.
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 dose based on the drug's specifications and calculate the required amount according to standard skin test concentrations. For example, with a common 1 g vial, the drug should be dissolved and progressively diluted to the specified concentration to ensure precise dosing and avoid affecting test accuracy.
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 a total volume of 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. Ensure thorough mixing after each dilution 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 to prevent degradation or contamination.
The preparation must be performed by trained healthcare professionals following strict aseptic techniques and dosage guidelines. The solution should be used within the recommended time; if expired, it must be re-prepared. Any abnormal appearance such as cloudiness requires immediate disposal and re-preparation to ensure patient safety.
