Active pharmaceutical ingredient solid-state characterization

To provide a forum for information exchange of issues relating to solid- and liquid-state characterization of chemical entities, active pharmaceutical ingredients, excipients, and early-phase development of pharmaceutical dosage forms and delivery systems... 

Characterization starts once the synthetic route has been selected, although there will be opportunities to modify the route if the changes do not impact the final solid state or impurity profile of the final active pharmaceutical ingredient. The primary objective is to understand, through experimentation, the chemical and physical chemical processes involved in the transformation of raw materials to intermediates and products. The primary outcome is a process definition that includes the order of manufacturing steps, process parameter control methodology, process parameter limits, raw material specification, and diagnostic metrics. 

In the following pages, an attempt will be made to describe many of the properties of the solid state that come into play and need to be considered when formulating low-dose pharmaceuticals. The solid forms may be broadly classified as crystalline and amorphous and then describe the solid-state techniques used in their characterization. Many of the quantitative aspects and their respective advantages and disadvantages will be described. Finally, a few approaches will be described that may be used to investigate the effect of formulation on the low-dose active ingredient in the tablet. 

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