The effect of polymorphism on active pharmaceutical ingredients: A review

Abstract

Active pharmaceutical ingredients (API) are the main components in the production process of pharmaceutical products. If the API has a good quality, then it will lead to good pharmaceutical products. API consists of more than one different crystal form which, then forms a polymorph through the process of polymorphism. Until now, API polymorphism is still a big challenge in the pharmaceutical industry. That is because the nature of polymorphism is difficult to predict. One of them is by crystallizing molecules in one or many crystalline forms or combining with other molecules to form stable co-crystal. This process will lead to several polymorph forms of one certain API. Sometimes, these forms will have characteristics that differ one to another. Each polymorph has different mechanical, physical, thermal, and chemical properties that will affect the solubility, dissolution, bioavailability, stability, bioequivalence, and manufacturing of the API. Therefore to know the nature of an API, it is necessary to characterize the polymorphic form of the API before. If the form is not incompatible with the formulation, it can cause a failure in the production process. This review will discuss the effect of polymorphism on the physicochemical properties of API. It is hoped that this review can become the basis for improving the stability and effectiveness of pharmaceutical products.