He wāhanga nui te Hydroxypropyl Methylcellulose (HPMC) cellulose ether i roto i ngā piri tāera uku, ā, he pānga nui tēnei ki te mahi a ngā piri. He hononga tata te tikanga whakapiri tāera uku me te nui o te HPMC cellulose ether i roto i te piri, nā te mea me whakarite ngā āhuatanga o te piri ki ngā whakaritenga motuhake o ngā tikanga whakapiri tāera rerekē. Anei te pānga o te tikanga whakapiri tāera uku ki te nui o te HPMC cellulose ether pai rawa atu i roto i te piri: