What are the dissolution methods of hydroxypropyl methyl cellulose (HPMC)?

Hot water dissolution method: Since HPMC is insoluble in hot water, the initial HPMC can be dispersed uniformly in hot water and then dissolved rapidly during the cooling process. Two typical methods are described as follows.

Put the required amount of hot water into a container and heat it to about 70°C. Gradually add hydroxypropyl methylcellulose under slow stirring, HPMC floats on the water surface and gradually forms a slurry, stirring to cool the slurry.

Add 1/3 or 2/3 of the required amount of water to the container, heat to 70°C, disperse HPMC according to 1) to prepare hot water slurry; then add the remaining amount of cold water to the hot water slurry, stir and cool.

Powder mixing method: HPMC powder is mixed with a large amount of other powdery substances, mixed thoroughly with a mixer, and then dissolved with water. At this time HPMC can be dissolved without lumping, because there is only a little HPMC in each tiny corner. the powder will dissolve immediately after contact with water. This method is used by putty powder and mortar manufacturers.