Disintegrating agents are chemical agents consisting of a mixture of substances or a single substance that are added to tablets and other encapsulated formulations to facilitate disintegration of the capsule or tablet into smaller remains for better discharge of the drug in the body. This process helps provide better results of the drug on the body. Disintegrating agents primarily find application in the pharmaceutical industry. These agents are used in the preparation of tablets and other formulations. Disintegration plays a major role in facilitating drug activity. There are various stages or procedures based on which a disintegrating agent can be added to the drug formulation. Based on its procedure of adding, the process can have a profound influence on the effectiveness of the drug. When a disintegrating agent is added before the granulation process, it is known as intragranular. When it is added after granulation and before the compression process, it is called as extragranular. A disintegrating agent can also be added at both intragranular and extragranular stages.
Three mechanism involved in drug or tablet disintegration are swelling, wicking, and deformation. In the swelling mechanism, the product that is disintegrating agent impart the disintegrating effect through swelling. Starch is a type of disintegrating agent that shows this mechanism. The disintegrating agent that does not swell, exhibits disintegrating effect through wicking, i.e., through porosity and capillary action. Disintegrating agents with low cohesiveness and compressibility enhance porosity and provide pathways into the tablet or drug. In the deformation mechanism, the disintegrating agent is deformed or distorted under pressure during tableting. The deformation of the disintegrating agent helps improve the performance of the drug. There are other mechanisms involved in drug or tablet disintegration, such as enzymatic action, gas release, and exposure to heat.
Various types of disintegrating agents used in drug formulations include starch, cellulose, and polyvinylpyrrolidone. Starch was the first disintegrating agent that was widely used for tablet manufacturing. Potato starch and corn starch were the original type of starch used as a disintegrating agent. Microcrystalline cellulose is a type of cellulose that is widely used for flow and binding in drug formulations. It exhibits effective tablet disintegrant when used in a concentration ranging between 10% and 20%. Polyvinylpyrrolidone is another kind of disintegrating agent used in drug formulations. Other disintegrating agents used in drug formulations or tablets are alginates and ion-exchange resins. Superdisintegrants are a category of segment that shows faster disintegration. Rise in the demand for faster disintegrating formulations has increased the requirement for superdisintegrants across the globe. Superdisintegrants are effective at low concentration, have greater disintegrating efficiency, and are effective intragranularly.
Examples of superdisintegrants include modified starches, modified celluloses, and cross-linked polyvinylpyrrolidone. However, superdisintegrants are hygroscopic; therefore, they are not used in moisture sensitive drugs.