**3.4 Formation of amorphous or crystalline solids**

The drying process can cause the formation of amorphous or crystalline solids, which can affect the drug**'**s solubility, stability, and bioavailability. Amorphous solids are less stable than crystalline solids, and they tend to have a shorter shelf-life. On the other hand, crystalline solids can be challenging to dissolve, leading to reduced bioavailability. Therefore, it is essential to optimize the drying conditions to control the physical form of the final product.

The challenges associated with pharmaceutical drying can affect the quality, stability, and efficacy of the final product. Therefore, it is crucial to optimize the drying conditions to ensure that the products are dried efficiently without compromising their stability and potency. The drying process must be carefully monitored to prevent the formation of amorphous or crystalline solids, and proper solvent removal techniques must be employed to prevent the presence of residual solvents.
