There is a disintegration tester in the laboratory, why do a dissolution tester is still required? Let us first learn about the process of drug absorption in the body.
Before the human body absorbs the drug in the solid preparation, it must undergo a process of disintegration and dissolution and then into a solution. The speed of dissolution determines the absorption speed of the drug in the body. If the drug is not easily released from the preparation or the dissolution rate of the drug is extremely slow, It is possible that the absorption speed or extent of the drug in the preparation may be affected. In addition, some drugs with strong pharmacological effects, low safety index, and rapid absorption may cause obvious adverse reactions if the dissolution rate is too fast, and the time to maintain the efficacy will also be shortened. In this case, the dissolution rate of the drug in the preparation should be controlled.
Relying on the disintegration time limit inspection as the evaluation standard for the absorption of all tablets and capsules in the body is obviously not feasible, because the particle size passing through the disintegration tester screen after the drug is dissolved is often between 1.6-2.0mm, but the drug needs to be in a solution state to be absorbed by the body, and the particle size is calculated by A, so the disintegration is only the initial stage of the dissolution of the drug, and the disintegration time limit inspection cannot control the subsequent dispersing and dissolving process. Moreover, the disintegration of the solid preparation is subject to the prescription design , preparation, storage process and many complex factors in the body, so the disintegration time limit inspection cannot objectively reflect the relationship and influence between the drug and excipients, but the dissolution test includes the disintegration and dissolution process, so the dissolution degree has a more important meaning. This is the important reason why the laboratory has a disintegration tester and also needs a dissolution tester.
From the perspective of drug testing, the dissolution rate refers to the rate and extent of the dissolution of a drug from a solid preparation such as a tablet or capsule in a prescribed solvent. Most oral solid preparations must be absorbed into the blood circulation after administration, and only after reaching a certain blood drug concentration can they be effective. Therefore, the release of the drug from the preparation and dissolution in body fluids is the prerequisite for absorption. This process is called dissolution in biopharmaceutics, and the rate and degree of dissolution is called dissolution rate.