Hydroxypropyl methylcellulose (HPMC) is a key ingredient in many vitamins and dietary supplements, playing a vital role in the formulation and efficacy of these products. This compound is a derivative of cellulose, a naturally occurring polymer that makes up plant cell walls. Making HPMC by modifying cellulose requires the addition of hydroxypropyl and methyl groups, resulting in a water-soluble multifunctional substance with a wide range of applications.