The Effect of Particle Size on Drug Bioavailability

Controlling the particle size of a drug is a key part of drug preparation. The size of the drug particle size can directly affect the solubility and dissolution rate of the drug, thereby affecting the clinical efficacy. For example, in the development of solid preparations, reducing the particle size of drug particles can significantly increase the dissolution rate of insoluble drug tablets. In the current drug research and development process, the particle size of drugs is also constantly shrinking. Methods and technologies for reducing the particle size of drugs include micronization technology, microemulsion, solid dispersion technology, liposome method, microcapsule method, microsphere method and recrystallization method. Reducing the particle size can reduce the bioavailability of poorly soluble drugs, enhance drug efficacy, and achieve drug targeting effects.

Reducing the Particle Size can Reduce the Bioavailability of Poorly Soluble Drugs

The particle size has little effect on the solubility of soluble drugs, but for poorly soluble drugs or drugs with a slow dissolution rate, the dissolution process of the drug often becomes the rate-limiting process of absorption. Generally speaking, reducing the particle size of the drug to a certain degree of fineness can increase the surface area of the drug and promote the dissolution of the drug. Moreover, when the particle size of the drug decreases, its specific surface area increases, and the effective contact area between the drug and the medium increases, which will increase the dissolution rate and dissolution rate of the drug. In the development of solid preparations, reducing the particle size is to improve the bioavailability of poorly soluble drugs. An effective method.

In pharmacy, microemulsion can improve the solubility of poorly soluble drugs and promote the absorption of drugs, thereby improving the oral bioavailability of drugs. Some researchers used insoluble simvastatin and alendronate sodium with poor gastrointestinal permeability as model drugs, and prepared microemulsion preparations to improve their oral bioavailability, and thus explored the microemulsion drug delivery system Application potential in improving the oral bioavailability of Class II and Class III drugs in the biopharmaceutical classification system [1]. Taking Beagle as the experimental animal and choosing other reference preparations, the average relative bioavailability of the two microemulsion preparations was 193.02% and 294.95%, respectively, which significantly improved the bioavailability of the drug, indicating that the microemulsion administration The system can improve the oral bioavailability of Class II and Class III drugs in the biopharmaceutical classification system.

The particle size of the raw materials and related preparations is very important for the evaluation of drug performance and consistency. Whether it is a solid oral, suspension, injection or even inhalation preparation, the size and distribution of drug particles will have a significant impact on the preparation process and process. Medicilon has the equipment and instruments commonly used for preparation process research and quality research such as tablets, injections, capsules, granules, ointments, creams, sprays, gels, syrups, tinctures, oral liquid preparations, and oral liquid preparations. The solid preparation GMP pilot plant also has the ability to develop new technologies such as sustained and controlled release preparations, nano preparations, and fat emulsions.

Reducing the Particle Size can Enhance the Efficacy of the Drug

Reducing the particle size of the drug is beneficial to the preparation of various drug dosage forms, and reducing the particle size of the drug is also convenient for the formulation, administration and efficacy of the drug. No matter what form of drug is administered, the particle size of the drug will affect the release of the drug from the dosage form, which in turn affects the efficacy. While improving the disintegration and dissolution of the drug, the absorption of the drug is increased, and the bioavailability and efficacy can be better improved.

For example, researchers have prepared quercetin liposome nanoparticles, and tested the drug content, encapsulation efficiency, and particle size of the nanoparticles. A liver damage model that mimics the natural process of the human body was prepared with multiple factors, and the therapeutic effect of the quercetin liposome nanomedicine on the liver after being injected into liver injury rats was observed and compared with each control group [2]. The results of the study found that the nano-sized quercetin liposomes have stronger free radical scavenging and antioxidant effects. It can significantly enhance liver targeting, and can eliminate a large number of free radicals in the body, so as to achieve better protection of liver cells. Both liver function data and pathological results analysis show that quercetin liposome nanomedicine is better than non-nanoized quercetin on the liver. Blank liposome nanoparticles also have a certain therapeutic effect on rat liver.

In addition, the size of the particle size determines the efficacy and side effects of the drug. Changing the size of the particle size can change the distribution characteristics of the drug in the body. The stronger the drug’s targeting, the smaller the side effects will be, and it can be used for targeting. Formulation research and development.

[1] Application research of microemulsion drug delivery system in improving the bioavailability of poorly soluble and poorly permeable drugs [J].

[2] Therapeutic effect of quercetin liposome nanomedicine on liver injury in rats[J].