Hydroxypropyl methyl cellulose, commonly abbreviated as HPMC, is a versatile pharmaceutical excipient widely used in the formulation of various dosage forms. This semi-synthetic polymer is derived from naturally occurring cellulose, which is modified through the addition of methoxy and hydroxypropyl groups to improve its solubility and stability in water. The resulting compound possesses unique characteristics that make it an indispensable component in the manufacturing process of tablets, capsules, films, and even some types of suspensions and emulsions. One of the primary functions of HPMC is as a binder in the production of tablets. It provides cohesion between particles, ensuring that the tablet maintains its structure during compression and post-production handling. Moreover, HPMC can act as a release-controlling agent due to its ability to form a gel layer upon contact with aqueous fluids. This property allows for the sustained or controlled release of active pharmaceutical ingredients (APIs), which can optimize therapeutic efficacy by maintaining drug levels within the desired therapeutic window over an extended period. In addition to its role in solid dosage forms, HPMC also finds application in the preparation of film coatings. These coatings protect the core tablet or capsule from environmental factors such as moisture and light while improving the aesthetic appeal and patient acceptability of the medication. Furthermore, the use of HPMC in film coatings can facilitate the development of modified-release dosage forms, where the rate at which the API is released into the body is carefully managed to suit the treatment regimen. Another notable advantage of using HPMC is its non-toxicity and biocompatibility Another notable advantage of using HPMC is its non-toxicity and biocompatibility
The applicant did not provide new studies on the safety of HPMC, but made reference to previous assessment of celluloses (as a group) performed by other scientific bodies. Cellulose and cellulose derivatives were evaluated for their safety by JECFA (1990), which allocated a group ADI of ‘not specified’. The last comprehensive evaluation of cellulose and cellulose derivatives, including HPMC, for their use as food additives was done in 2017 by the ANS Panel (EFSA ANS Panel, 2018), which concluded that there was no need to set a numerical ADI. Although the data set available for the different celluloses is not complete and most of the studies were old and do not meet the current requirements of toxicological testing, the ANS Panel considered that the physico-chemical, structural, biological and kinetic similarities between the modified celluloses make it possible to apply a read-across approach among the different celluloses.