No, hypromellose and hydroxypropyl cellulose are not the same.
Hypromellose, also known as hydroxypropyl methylcellulose (HPMC), is a semi-synthetic, inert, viscoelastic polymer used as an ophthalmic lubricant, an oral excipient, a tablet binder, and a film former. It is a derivative of cellulose and is composed of repeating units of the sugar glucose. Hypromellose is used in a variety of pharmaceutical, cosmetic, and food products, and is generally regarded as safe (GRAS) by the U.S. Food and Drug Administration (FDA).
Hydroxypropyl cellulose (HPC) is a semi-synthetic polymer derived from cellulose. It is composed of repeating units of the sugar glucose and is used as a thickening agent, stabilizer, and suspending agent in a variety of products. HPC is generally regarded as safe (GRAS) by the U.S. Food and Drug Administration (FDA).
Although both hypromellose and hydroxypropyl cellulose are derived from cellulose, they are not the same. Hypromellose is a derivative of cellulose that contains hydroxypropyl groups, while hydroxypropyl cellulose is a polymer of cellulose that contains hydroxypropyl groups. Hypromellose is used as an ophthalmic lubricant, an oral excipient, a tablet binder, and a film former, while hydroxypropyl cellulose is used as a thickening agent, stabilizer, and suspending agent.