X-ray diffraction (XRD) is a useful form of analysis that can be used to accurately and unambiguously characterise the compositions in pharmaceutical formulations. This is because each crystal structure of the composition displays a unique XRD pattern and so it is possible to access the parameters of the crystal structure. It is also possible to isolate and index the active ingredient in the formulation and on the basis of its unique XRD pattern the substance can also be patented. This way the pharmaceutical company can be sure of the fact that its investment in a new drug formulation or discovery is secure. In fact XRD is excellent for compositions that use multiple ingredients because XRD can help detect the percentage of active ingredients to be used in the final dosage.
X-ray diffraction analysis has become one of the major techniques for solid state analysis as well. XRD is used in all stages of pharmaceutical formulation including development of new drugs, testing as well at the production stage. It is important to know which of the substances used in the formulation is the most stable. During screening of substances it is also possible to discover any polymorphism which can cause physical changes. Physical changes can bring about changes in the solubility of drug substances. Solid state characterisation can also be required for easy manufacturing, for bioavailability of the drug substances as also for product stability. There are a number of techniques other than XRD that can be used for verifying chemical purity and composition but none of them are good for identification of crystal forms other than XRD.
XRD analysis makes it possible to detect the percentage of amorphous packing ingredients. Amorphous solutions are considered unstable and if they precipitate it can lead to dissolution of the drug or cause poor bioavailability. Therefore, it is important to understand if or at what stage the substance can crystallize. Sometimes drugs have to be prepared in amorphous forms because of poor water solubility. In case there is a need to prepare the drug as an amorphous form, XRD can be used to detect what changes can occur in the drug during storage especially if there is high humidity.
XRD has many applications as far as pharmaceutical analysis go as it can be used to identify even unknown drug materials. This is the reason why XRD is most often used for problem solving and for drug discovery. X-ray diffraction is used to discover and design new pharmaceutical formulations based on specific knowledge of active ingredients. Through XRD analysis these active ingredients can be used in the correct proportion to control disease. XRD proves useful in drug design especially as it can analyse large as well as small molecules. XRD is also used in the formulation of synthetic pharmaceutical mixtures as these could pose analytical problems by other methods. Sample preparation by skilled and experienced technicians is important for synthetic pharmaceutical mixture analysis as these samples can have complexities.