How to simply and intuitively judge the quality of hydroxypropyl methylcellulose (HPMC)?

How to simply and intuitively judge the quality of hydroxypropyl methylcellulose (HPMC)?

(1) Proportion: The larger the proportion, the heavier the better.

(2) Whiteness: Although whiteness cannot determine whether HPMC is easy to use, and if a brightener is added in the production process, it will affect its quality. However, most good products have good whiteness.

(3) Fineness: The fineness of HPMC is generally 80 mesh and 100 mesh, 120 mesh is less, mostly 80 mesh, the finer the finer, the better in general.

(4) Transmittance: Put hydroxypropyl methylcellulose (HPMC) in water to form a transparent colloid, and look at its transmittance. The greater the transmittance, the better, indicating that there are less insolubles inside. . The permeability of the vertical reactor is generally good, and the horizontal reactor is worse, but it does not mean that the quality of the vertical reactor is better than that of the horizontal reactor. The product quality is still determined by many factors. The higher the hydroxypropyl content, the better the water retention.