Bacterial endotoxins and injectability

5. Hydroxypropyl Methylcellulose can mix with water-soluble polymers and then form a uniform solution of higher viscosity, such as polyvinyl alcohol, starch ethers, and vegetable gums.

The majority of the available studies have been performed in rats, just few of them in rabbits and dogs. Among those meeting the current criteria for toxicological testing, the no observed adverse effect level (NOAEL) values for the different modified celluloses were identified most often corresponding to the highest tested level or changes in body or organ weights. For microcrystalline cellulose (E 460) the identified NOAELs in rats ranged from 3,769 mg/kg body weight (bw) per day to 9,000 mg/kg bw per day and in all cases corresponded to the highest levels of the test substance. For methyl cellulose (E 461), the dose level of 3% in rats (equivalent to 2,700 mg/kw bw per day) was selected as the NOAEL based on a decrease in body and organ weight displayed in male rats administered with the top additive level (10%, equivalent to 9,000 mg/kg bw per day and day).

Why do we use HPMC capsules?

2)The viscosity of Hydroxypropyl Methylcellulose is influenced by its molecular weight, with higher molecular weight leading to higher viscosity. Temperature also affects its viscosity, with viscosity decreasing as temperature rises. However, the impact of temperature on viscosity is lower compared to Methyl Cellulose. Its solution is stable when stored at room temperature.