When preparing film coatings, it is crucial to maintain which of the following properties?

Maintaining low viscosity during the preparation of film coatings is essential because it ensures that the coating solution can be easily applied and evenly distributed over the tablet or core. Low viscosity promotes better flow characteristics, which is critical for achieving a uniform layer during the coating process. This uniformity is important not just for aesthetics or consistency, but also for ensuring the desired release characteristics of the coated product, affecting both the physical and chemical stability of the drug.

In contrast, if the viscosity is high, it may result in difficulties in spraying or spreading the coating material evenly across the surface, leading to inadequate coverage or inconsistencies in the coating thickness. These discrepancies can adversely affect the overall quality, performance, and solubility of the final pharmaceutical product. Hence, maintaining low viscosity is a key factor in producing effective film coatings.