Characteristics And Application Of Hydroxypropyl Methylcellulose (HPMC) Hollow Capsules

With the increase of people's preference for capsules, hollow capsules are more widely used in the fields of food, medicine and health care products. However, the occurrence and spread of mad cow disease and foot-and-mouth disease have caused people to worry about animal-derived products. The most commonly used raw material for gelatin is the bones and skins of cattle and pigs, and its risks are gradually attracting attention. In order to reduce the safety risk of hollow capsule raw materials, industry experts continue to research and develop suitable plant-derived capsule materials. In addition, with the increase in the variety of capsules, the diversity of their contents has gradually made people realize that gelatin hollow capsules have compatibility problems with some special contents. For example, content containing aldehyde groups or reacting to form aldehyde groups under certain conditions may cause cross-linking of gelatin; content with strong reducibility may undergo mailard reaction with gelatin. ); The strong hygroscopic content will cause the capsule shell to lose water and lose its original toughness. The stability of the above-mentioned hollow gelatin capsules has caused more attention to the development of new capsule materials. Which plant-derived materials are suitable for the production of hollow hard capsules? Many attempts have been made. Chinese Patent Document Application No. 200810061238.x applied for sodium cellulose sulfate as the main capsule material; 200510013285.3 applied for starch or starch composition as the main capsule material; wanggm [1] reported the manufacture of hollow capsules with chitosan capsule raw materials; Zhang Xiaoju et al. [2] reported a product with konjac-soybean protein as the main capsule material. Of course, cellulose materials are the most studied. Among them, hollow capsules made of hydroxypropyl methylcellulose (hpmc) have formed large-scale production. hpmc is widely used in the field of food and medicine. It is a commonly used pharmaceutical excipient and is included in the pharmacopoeias of various countries; fda and the European Union approve hpmc as a direct or indirect food additive; gras is included as a safe substance, number no. grn000213; included in the jecfa database, insno.464, does not limit the maximum daily dose of hpmc; in 1997, the Ministry of Health of China approved it as a food additive and thickener (No. 20), suitable for all kinds of food, according to The production requirement is added [2-9]. Due to the difference in properties of gelatin, the prescription of hpmc hollow capsules is more complicated, and some gelling agents, such as gum arabic, carrageenan (algae gum), starch, etc. need to be added. The hpmc hollow capsule is a product with a natural concept. Its material and production process are recognized by the Jewish, Islamic and Vegetarian Associations. It can meet the needs of people with various religions and eating habits and has a high acceptance. In addition, hpmc hollow capsules also have the following unique properties: Low water content—about 60% lower than gelatin hollow capsules The water content of gelatin hollow capsules is generally 12.5%-17.5% [10]. The temperature and humidity of the environment should be controlled within an appropriate range during the production, transportation, use and storage of hollow capsules. The suitable temperature is 15-25℃, and the relative humidity is 35%-65%, so that the product performance can be maintained for a long time.