
Is it safe?: In an FDA study with rats, there were no significant toxic effects other than growth retardation once HPMC reached levels of 20 to 30% of the rats’ diet. This study noted that growth retardation may be contributed to malnutrition and not the amount of HPMC. In another study, rabbits were injected with 2% HPMC for over a month and there were no observations of toxicity or irritation. Overall, the FDA sees it as a non-toxic and non-irritating inactive ingredient that is safe for human use and consumption.
Hydroxypropylmethyl cellulose is a cellulose ether with both methyl and hydroxypropyl functional group substitutions. Hydroxypropylmethyl cellulose (HPMC) is a nonionic thermoplastic polymer that dissolves in water to produce a solutions with a wide range in viscosity. It has greater gelling capacity than hydroxypropyl cellulose (HPC) and is more tolerant to salts and additives. HPMC is used as a thickening agent, stabilizer, emulsifier and film forming agent. Aging studies indicate that HPMC has very good stability with negligible discoloration or weight loss (Feller and Wilt 1990).





hpmc powder.