Role of continuous moisture profile monitoring by inline NIR spectroscopy during fluid bed granulation of an Enalapril formulation

Background: Granulation and tableting are closely related process steps in the supply chain of pharmaceutical products. Even today, these steps are still optimized independently by trial and error. On the framework of a process analytical technology approach, these processes were evaluated in an integrated approach. Enalapril maleate is a low-dose drug substance with poor granulating and tableting behavior. In order to verify how granulation influences tableting properties, different granulation experiments were performed. Methods: Granulation experiments with fast spraying rate and fast drying as well as fast spraying rate and slow drying, and also combinations of both were run. The obtained granules were then promptly compressed into tablets in a rotary press and subjected to hardness testing. The progress of spraying and drying was controlled by a continuous near-infrared spectroscopic measuring setup. This study confirms that the tablet characteristics. Result/Conclusion: after compression of the granules in comparison to placebo granules are dependent not only on the residual moisture content of the granules but also on the moisture profiles during the entire fluid bed granulation process.