Many users are faced with a situation where the usual drug stored in the medicine cabinet suddenly changes its consistency. Dimexide is a popular anti-inflammatory drug that is often kept at home as compresses for injuries or joint pain. However, when stored at low temperatures, for example, on the refrigerator door, the liquid can turn into a thick porridge or even a solid mass.
There is no need to panic in this case, since this phenomenon is of a purely physical nature. Dimethyl sulfoxide, which is the main active ingredient of the drug, has a specific temperature crystallization. Understanding the chemical properties of this compound will allow you to correctly assess the condition of the medicine and safely use it after reconstitution.
In this article we will look in detail at why concentrated solution changes its state in the cold, whether its medicinal properties are lost and how to return the drug to its original form. You will learn about storage rules that will help you avoid similar situations in the future, and you will understand when the medicine is really spoiled and when it can be resuscitated.
Physical properties of dimethyl sulfoxide
To understand the nature of freezing, you need to turn to chemistry. The basis of the drug is a substance with the formula (CH₃)₂SO, known as Dimexide. It is a colorless viscous liquid that mixes with water in any proportions. The key characteristic that determines the behavior of the drug in the refrigerator is its high hygroscopicity.
The substance actively absorbs moisture from the air, which can affect its physical parameters. However, the pure substance itself has a clearly defined melting point. For pure dimethyl sulfoxide it is about +18...+19°C. This means that at room temperature it is in a liquid state, but slight cooling can start the crystallization process.
In pharmacies, the drug is most often sold as a concentrate (99% or 98%) or an aqueous solution (usually 50% or 30%). The presence of water in the composition significantly changes the freezing temperature threshold. If you keep the bottle in the refrigerator, where the temperature is usually +4...+5°C, you will inevitably fall below the crystallization point for many concentrations.
It is important to note that the process of transition from liquid to solid is reversible. This is not a chemical reaction of the decomposition of molecules, but a change in the state of aggregation. Molecular structure the substance is preserved, which allows us to hope for a complete restoration of pharmacological properties after warming.
Temperature storage of the drug
Drug manufacturers always indicate the recommended storage conditions on the packaging. For Dimexide the standard requirement is a temperature of no higher than 25°C. Many people mistakenly believe that the “refrigerator” is a universal place for all medications, but in this case it can play a cruel joke.
Why does the drug end up in the cold? This often happens for two reasons: either the user is playing it safe, wanting to extend the shelf life, or the room is too hot, and the refrigerator seems to be the only salvation. However hypercooling causes the solution to become cloudy and thick.
Let's consider the dependence of the state of the substance on temperature:
- ❄️ At +18°C and below, pure Dimexide begins to crystallize, turning white mass.
- 💧 At +20...+25°C the drug is a transparent viscous liquid without sediment.
- 🌡️ At +30°C and above, the volatility of the substance increases, which requires tightly sealing the bottle.
- 🧊 Aqueous solutions (50%) can withstand lower temperatures, but the risk of delamination remains.
If you notice that the liquid has become like semolina porridge or has frozen completely, this is a direct signal that the temperature regime has been disturbed downward. Unlike many other medicines, Dimexide is not destroyed by cold, but its use in crystalline form is impossible and inconvenient.
It should also be taken into account that sudden temperature changes can contribute to faster crystallization. If you take the bottle out of a warm bag and immediately put it on the refrigerator shelf, the process of crystal formation will go faster. Stability of conditions is the key to preserving the liquid form of the drug.
Crystallization process and change in consistency
Visually the freezing process looks pretty special. At first, individual flakes or slight turbidity may appear in the clear liquid. Then the mass becomes thicker, resembling jelly or thick syrup. At the final stage, a dense white precipitate or monolithic mass is formed, which does not drain when the bottle is tilted.
This phenomenon is called crystalline hydrate formation (if there is water) or simply crystallization. The molecules of a substance are arranged in a certain lattice. It is noteworthy that the volume may change slightly, but the bottle, as a rule, remains intact, since Dimexide does not expand as aggressively as water when it freezes.
⚠️ Attention: If after defrosting you see a cloudy precipitate that does not disappear, or feel a sharp unpleasant odor (different from regular garlic), the drug cannot be used. This may indicate a violation of the seal of the package or expiration of the expiration date.
Crystallization affects not only the pure substance, but also diluted forms. However, in dilute solutions the process may proceed unevenly. Water and dimethyl sulfoxide can crystallize at different temperatures, which leads to separation of the contents of the bottle. That is why it is important to carefully stir the drug after the temperature has been restored.
The table below shows approximate temperature thresholds for various conditions:
| Concentration | Temperature of onset of crystallization | Appearance when cooled |
|---|---|---|
| 99% (Concentrate) | +18.5°C | White mushy mass |
| 50% Solution | about 0°C...-5°C | Cloudiness, flakes |
| 30% Solution | below -10°C | Freezing of the entire mass |
| Gel (30%) | depends on basics | Thickening, loss of elasticity |
Understanding these differences helps determine how much the medicine has frozen. If you store 99% concentrate, then just a cool room in winter is enough to freeze it, not to mention a refrigerator.
Is it possible to use frozen Dimexide
This is the most important question that worries patients. The answer is clear: Can be used, but only after complete restoration of its physical properties. As mentioned earlier, freezing is a physical process that is reversible when heated. The chemical formula of the substance does not change, and the therapeutic effect remains.
However, using the drug immediately after removal from the cold is strictly prohibited. Crystals can damage the skin or mucous membrane, and uneven concentration (if separation occurs) will lead to a chemical burn or lack of effect. You need to wait until the mass becomes a homogeneous transparent liquid again.
☑️ Checking the drug before use
The recovery process is simple, but takes time. Do not try to speed it up by heating the bottle over an open fire or in a microwave oven. Dimethyl sulfoxide is a flammable substance, and such experiments can be dangerous. In addition, overheating can lead to decomposition of the active components.
If you plan to make compresses after defrosting, remember the dilution rule. The concentrated drug should always be diluted with water, even if it is completely reconstituted. Applying a pure substance to the skin will cause severe burning and redness.
How to properly defrost the drug
To return the medicine to its liquid form, it is necessary to increase its temperature to room temperature (+20...+25°C). The easiest and safest way is to leave the bottle at room temperature for several hours. Usually the process takes from 2 to 6 hours, depending on the volume of the bottle and the degree of freezing.
If there is no time to wait, you can speed up the process, but this must be done carefully:
- 🤲 Place the closed bottle in a container with warm water (not hot!). The water temperature should not exceed +40°C.
- 🔄 Shake the bottle periodically to mix the contents and equalize the temperature.
- ☀️ You can place the bottle on the radiator, but always through a towel to avoid direct contact with hot metal.
It is important to ensure that the bottle cap is tightly closed. When heated, the pressure inside may increase, and volatile vapors will begin to escape. The specific smell of Dimexide is very persistent and quickly spreads throughout the room, causing a sensation of garlic taste in the mouth of everyone in the room.
Why does a garlic smell appear in the mouth?
Dimethyl sulfoxide has a unique ability to penetrate the skin and mucous membranes. Once in the blood, it quickly spreads throughout the body and is excreted through the lungs, giving the exhaled air a characteristic smell of garlic or oysters. This is normal and goes away within 24-48 hours.
After the crystals have disappeared and the liquid has become clear, shake the bottle thoroughly. This ensures that the concentration of the substance has become uniform throughout the volume. Only after this the drug is ready for dilution and use as prescribed by a doctor.
Storage rules and precautions
To avoid re-freezing and spoilage of the medicine, simple rules should be followed. Store Dimexide in a place protected from direct sunlight, but at a stable room temperature. A cabinet in the hallway or bedroom, away from heating appliances, is ideal.
Do not leave the bottle in unheated rooms in winter (for example, in a country house or garage), as a nighttime drop in temperature can again lead to crystallization. Also avoid storage in a car, where temperature changes are most dramatic.
⚠️ Attention: Dimexide is a powerful solvent. It can damage some types of plastic and rubber. Always check the integrity of the bottle and dropper cap. If the plastic has become brittle or cracked, it is better to pour the drug into a glass container.
Maintaining tightness is another important aspect. Since the substance is hygroscopic, opening the lid will absorb moisture from the air. This will change the concentration of the solution, and the table of freezing temperatures given above will no longer be relevant for it. Always screw the cap tightly immediately after use.
If you rarely use the drug, write the date the bottle was opened on the label. Although Dimexide itself is stable, in diluted form (if you prepared the solution in advance) it does not last long. It is better to prepare a solution for a compress immediately before the procedure.
Frequently asked questions (FAQ)
Can Dimexide be heated in the microwave if it is frozen?
It is strictly not recommended. The microwave heats unevenly, local overheating may occur, leading to decomposition of the substance or even ignition of vapors. In addition, the plastic bottle may melt. Use only a water bath or room heat.
Will the smell of the drug change after freezing and thawing?
No, the specific smell should remain the same. If after defrosting there is a smell of rot, acid or chemical burning, the drug cannot be used - it is spoiled.
How long should Dimexide be kept warm after refrigeration?
Usually 2-4 hours at a temperature of +22°C is enough. If the bottle is large (100 ml or more) or the room is cool, the process may take up to 6-8 hours. The main thing is to wait until the white flakes completely disappear.
Is it possible to use Dimexide if it has partially crystallized, but I shook it?
No. Until the crystals have completely dissolved, the concentration of the substance in the solution will be uneven. You may apply too much concentration to your skin and cause a burn. Wait for complete transparency.
Does freezing affect the shelf life of the medicine?
Short-term freezing and subsequent thawing itself does not shorten the shelf life specified by the manufacturer, provided that the packaging has not been damaged. However, multiple freeze-thaw cycles are undesirable.