Understanding the Role and Importance of Cosolvents in Drug Development and Experimentation

As we all know, all reagents need a certain dose to achieve the effects of inhibition, activation or compensation. The solubility and dissolution state that the drug can achieve is one of the key factors. That will decide which methods the experimenter chooses.

If the solubility of a drug is very low and cannot be completely dissolved in the solvent, the experimental data obtained often contains large errors or even complete errors. To obtain a high-concentration, completely dissolved preparation that can be used in cell or animal experiments, it is often inseparable from the role of cosolvent.

Cosolvent Define - What Is A Cosolvent?

Co-solvent: The poorly soluble drug and the added third substance form a soluble intermolecular complex, association or double salt in the solvent. The cosolvent is mainly used to increase the solubility of the drug in the solvent. Solubility enhancement by cosolvent.

Generally speaking, co-solvents are mostly low-molecular compounds, which are soluble in water. After forming a complex with the drug, the solubility of the drug can be increased several times or even dozens of times. It can change the cosolvent effect on solubility.

How Cosolvent Increase Solubility?

When the experimental body is administered in a certain way, whether the molecule can well penetrate the biomembrane barrier and timely distribute to the required part of the body to play a role is closely related to its solubility and dissolution rate.

If the experimenter can only get the working solution in the form of suspension, in vitro experiments, insoluble particles are likely to be adsorbed outside the cell membrane and cause damage to the cells; in in vivo experiments, suspensions can generally only be taken orally or by gavage However, some drugs have low oral bioavailability after entering the stomach or cause damage to laboratory animals.

In layman's terms, the drug can only be better applied to the experimental body after it is fully dissolved. In the actual operation process, many drugs have low solubility in water/medium, it is difficult to obtain a clear solution, only soluble in chloroform and other organic solvents that are toxic to the experimental body, and are unstable after dissolution, easy to degrade and inactivate, and the dissolved solution The concentration is lower than the effective range and other issues.

How to turn insoluble solids into solutions that can be used in experiments is the first difficulty. There are many ways to increase solubility. At present, in drug screening, various cosolvents or solvent mixtures are commonly used to solubilize poorly soluble compounds. Cosolvents have become an indispensable role in improving the safety, stability and effectiveness of drugs.

How Do Cosolvents Work?

1. It can increase the solubility of the drug, increase the content of the main drug in the preparation, and have a strong absorption effect;

2. Does not affect the performance and effect of the drug;

3. No irritation and toxicity when used, and will not cause damage to the experimental body;

4. Its stability remains unchanged during storage and sterilization;

5. Generally cationic surfactants are not used as solubilizers. Anionic surfactants are only used in external preparations, while non-ionic surfactants are widely used. They are used in oral, external preparations and even injections.

How to Determine The Dosage of Co-solvent?

1. Design a reasonable pre-experiment for optimal concentration screening;

2. It should be selected that can increase the solubility of poorly soluble drugs at a lower concentration;

3. Concentration that is large in solubilization and non-toxic and non-irritating to the experimental body;

4. Ensure that the resulting solution is a completely dissolved, clear liquid;

5. In terms of the toxicity and irritation of surfactants, the non-ionic type is smaller than the anionic type and the cationic type;

6. Use the correct order of cosolvent/solubilizer addition.

The above is the relevant content of the co-solvent. If you need other chelating agents, please feel free to contact us. Thank you for reading.