Application of Ion Exchange Resin in Pharmacy
Ion exchange resin has been widely used in pharmaceutics, but its development also has its limitations. Time is proving the safety of drug lipid complex in the drug domain. The advantages of ion exchange resin will undoubtedly promote the continuous progress of ion exchange resin technology. Of course, today is mainly about the role of ion exchange resin in pharmacy.
1. Mask one's taste
The ion exchange resin exchanges with ionic drugs through self balanced ions to make drugs enter the framework of the ion exchange resin and adsorb each other by electrostatic interaction to form a drug lipid complex, while the olfactory sense is opposite to the drug
The drug in the lipid complex is insensitive, thus covering up the bad taste of the drug.
2. Solubilization
Class II drugs in the biopharmaceutical classification system (BCS) have low general dissolution and bioavailability due to their high permeability and low solubility. After the drug resin composite is made, the problem of some drugs will be improved. The main reason is that the dissolution rate of ionic drugs from drug resin complex is much higher than that of bulk drugs without increasing drug solubility, which plays a role in promoting dissolution. At present, the mechanism of ion exchange resin to promote dissolution is as follows: a single drug molecule is bound to the functional group of the resin, and there is no need to overcome the lattice energy during dissolution; Second, the ion exchange resin has certain hydrophilicity, and drugs are easy to be wetted; Third, the resinate has small particle size and porous structure, which increases the specific surface area of the drug in contact with the dissolution medium.
3. Improve stability
After the drug is adsorbed, it is dispersed in the polymer skeleton of the ion exchange resin, which can not only avoid the direct exposure of the drug to the external environment, but also avoid the direct contact of the drug with the internal environment of the human body, thus ensuring the stability of the drug.
(1) Improve the stability of drugs in production and storage
Some chemicals are unstable during production and storage due to their own nature. For example, vitamin B12 is unstable in acidic and alkaline environments, degrades when exposed to light, and has strong moisture absorption, which is difficult to preserve for a long time. The tablet can be prepared by combining it with ion exchange resin for 2 years.
(2) Improve the stability of drug release in vivo
When drug is released in the body, it is mostly affected by physiological factors such as gastrointestinal pH, temperature, gastric emptying, etc., especially the gastrointestinal pH. It is reported that the sales volume of proton pump inhibitors has exceeded 10 billion yuan, which indirectly reflects the obvious individual difference of gastrointestinal pH value. This undoubtedly affects the determination of the dosage of some drugs.
4. The application of the drug delivery system of slow and controlled release
On the basis of the oral substitute drug resin controlled release system, the drug resin is treated with an impregnant such as polyethylene glycol (PEG) 4000 and glycerin to prevent the resin from expanding in the aqueous medium. Water insoluble but permeable polymers such as ethyl cellulose coat the drug lipid complex as a rate control barrier to regulate drug release. Because the drug release is not affected by pH, enzyme activity, temperature and other factors in the gastrointestinal tract, it is considered to be a breakthrough in drug slow and controlled release technology.
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