Maintaining the effectiveness of immunobiological drugs directly depends on compliance with strict temperature conditions and proper organization of space inside refrigeration equipment. Violation of storage conditions, even short-term, can lead to an irreversible change in the physicochemical properties of the drug, making it useless or even dangerous for the patient. That is why the question of how to properly arrange bottles and boxes on shelves is critical for pharmacists and medical personnel.
The main problem is the uneven distribution of cold inside the refrigeration chamber. Depending on the design of the equipment, temperatures at different levels may differ by several degrees, which is unacceptable for those who are heat sensitive. Proper zoning of space allows you to create a stable environment that minimizes the risk of damage to expensive medicines. immunobiological drugs. Proper zoning of space allows you to create a stable environment that minimizes the risk of damage to expensive medicines.
In this article we will analyze in detail the layout of vaccines, requirements for equipment and nuances that are often overlooked when organizing a pharmacy warehouse or treatment room. Understanding these principles is the basis for ensuring patient safety.
⚠️ Attention: Temperature and storage requirements may vary depending on the specific type of vaccine and manufacturer. Always check the manufacturer's instructions and current regulatory documents, as standards may be updated.
Requirements for temperature conditions and equipment
Specialized refrigerators are designed for storing vaccines, which are capable of maintaining a temperature in the range from +2 to +8 degrees Celsius around the clock. Conventional household models often fail to cope with this task due to large temperature fluctuations when opening the door and cyclic operation of the compressor. The use of professional pharmaceutical equipment guarantees the stability of conditions.
The key parameter is the uniformity of cooling. Ideally, the temperature difference at any point in the working chamber should not exceed 1-2 degrees. To control this parameter, calibrated thermometers or electronic data loggers are used, which record the slightest deviations.
It is important to understand that the risk area is often located at the back wall where the evaporator is located. Here, the temperature can drop below zero, which will lead to the freezing of liquid forms of drugs. Freezing Adsorbed vaccines cause irreversible destruction of the adjuvant, and the drug loses its effectiveness, even if it looks normal after defrosting.
Zoning the refrigerator compartment: where to put the boxes
The correct distribution of drugs on the shelves is not just a matter of convenience, but a necessity for maintaining the cold chain. Each shelf has its own temperature profile, and ignoring this fact can cost a batch of the drug.
The top shelves are usually the warmest, as warm air rises. However, in modern models with a system No Frost or forced air circulation, the distribution of flows may be different. Therefore, the primary task is to conduct temperature mapping of a specific refrigerator.
- 🌡️ Middle shelves: This is the zone with the most stable temperature. It is recommended to place drugs here that require strict adherence to the +2...+8°C regime.
- ❄️ Bottom shelves: It is colder here, but the risk of local hypothermia is higher. Suitable for supplies packed in thermal containers or requiring slightly lower temperatures within normal limits.
- 🚫 Door shelves: Strictly not suitable for storing vaccines due to maximum temperature fluctuations when opening the door.
Distance between boxes should be at least 2-3 centimeters to ensure normal air circulation. Dense packing “back to back” creates “thermal pockets” where the temperature can be higher than the established norm.
☑️ Checking the placement
Danger of freezing and “warm pockets”
One of the main threats to the quality of vaccines is inadvertent freezing (accidental freezing). Many people think that if a drug is liquid, it cannot freeze, but this is a misconception. Solvents and adsorbed vaccines are extremely sensitive to crystallization.
“Warm pockets” form in the corners of the chamber or in the center of tightly packed stacks of boxes where air circulation is difficult. In these areas, the temperature may be higher than that indicated by the sensor located near the wall. This creates the illusion of well-being until the drug is used.
⚠️ Attention: Visual inspection does not always allow one to determine whether the vaccine has been frozen. Some changes are only visible under a microscope or when special tests are performed (for example, the “shake test” for adsorbed vaccines).To prevent these risks, it is necessary to avoid placing drugs close to the back wall of the refrigerator. The optimal distance is at least 5-7 centimeters. You should also avoid storing drugs on the floor of the chamber if there are holes for air circulation there.
What is the “shaking test”?
This is a simple method for monitoring the quality of adsorbed vaccines. The vial with the vaccine and the control vial (of the same series, but frozen) are shaken vigorously. If the sediment in the test vial settles faster than in the control one, it means that the vaccine was probably frozen and lost its properties.
Layout and product proximity
The organization of space inside the refrigerator should obey the logic of “first in, first out” (FEFO - First Expired, First Out). This means that drugs with an earlier expiration date must be located in an accessible area so that they are used first.
In addition, it is important to take into account the product proximity. Vaccines should not be stored together with food, reagents or other chemicals. This is a requirement for sanitary safety and the prevention of cross-contamination.
Refrigerator area Recommended placement Prohibited Top shelf Wide temperature products range Storage without packaging Middle shelf Main supply of sensitive vaccines Airflow blocking Lower shelf Stocks in thermal containers Placement at the back wall Door Alcohol wipes, consumables Any immunobiological preparations The use of plastic containers or baskets for grouping drugs of the same type or series simplifies inventory and reduces the risk of errors during dispensing. The labeling of such containers must be clear and readable.
Temperature monitoring and record keeping
The temperature monitoring system must operate continuously. Modern refrigerators are equipped with digital displays, but you can't rely on them alone. It is mandatory to maintain a temperature logwhere data is entered at least twice a day (morning and evening).
The log records the date, time, readings of the minimum and maximum thermometer, as well as the signature of the person in charge. If the temperature falls outside the permissible range, a corresponding entry is made in the log indicating the measures taken.
Thermometers used for control must undergo regular testing metrological verification. The use of household alcohol thermometers without a certificate in professional activities is unacceptable, since their error can be critical.
- 📝 Entries in the journal must be made in ink, corrections must be certified by a signature.
- 🔋 Electronic recorders must have autonomous power supply in case of a power outage.
- 📞 A list of contacts of responsible persons and technical support services in case of an emergency should hang in a visible place.
Actions in emergency situations
No one is insured against a power outage or equipment breakdown. In such cases, it is important to act quickly and according to the algorithm. The first step is always to assess the situation: how much time has passed and how much the temperature has changed.
If the refrigerator stops working, do not open the door unless absolutely necessary. This will help keep the cold inside longer. If a long shutdown is planned, the drugs must be moved to another working refrigerator or to thermal containers with cold elements.
⚠️ Attention: When placing cold elements in a thermal container, be sure to wrap them in several layers of paper or fabric. Direct contact of the vaccine with the ice element will lead to its instant freezing and spoilage.If the temperature is outside the normal range, the drugs should not be thrown away immediately. They are placed in a quarantine zone marked “Quarantine” until the circumstances are clarified and the authorized person decides on the possibility of further use.
Can a vaccine that has been thawed be used?
No, a thawed vaccine cannot be used. The freezing process destroys the adjuvant structure and cannot be restored. The use of such a drug may be ineffective or cause complications.
Frequently asked questions (FAQ)
Can vaccines be stored in a regular home refrigerator?
Technically, this is only possible in emergency cases and for a very short period of time, if the refrigerator is capable of stably maintaining a temperature of +2...+8°C and is equipped with a separate thermometer. However, for permanent storage in pharmacies and clinics, the use of household refrigerators is prohibited by sanitary standards due to the risk of temperature fluctuations and the lack of a monitoring system.
What to do if the vaccine accidentally freezes?
The use of such a drug is strictly prohibited. Frozen vaccine is marked as “Prohibited for use” and is placed in a separate container for subsequent disposal according to established rules. An attempt to “defrost and use” is unacceptable.
How often should the vaccine refrigerator be cleaned?
Regular cleaning should be carried out as needed, but at least once a month. It is important to use only approved disinfectants that do not have a strong odor, and thoroughly dry the chamber before loading drugs to avoid increasing humidity.
Do solvents need to be stored together with vaccines?
Solvents should also be stored in the refrigerator at a temperature of +2...+8°C, so that when mixing there is no temperature shock for the lyophilisate. However, they do not have to be stored in the same refrigerator if the other one provides identical temperature conditions. The main thing is not to freeze solvents.