Capsules in life There are many capsule medicines that people eat, which are colored and transparent. Regarding the classification of capsules, there can be many classifications according to the function, appearance, and effect of use. Some of these categories include vegetable capsules and gelatin capsules.

    The main component of vegetable capsules is medicinal hydroxypropyl methylcellulose (HPMC), namely 2-hydroxypropyl methylcellulose. Cellulose is the most abundant natural polymer in nature. HPMC is usually made from short cotton linter or wood pulp by etherification. The main component of the gelatin capsule is high-quality medicinal gelatin, which is derived from collagen in animal skin, tendons, and bones, and is a protein partially hydrolyzed from collagen in animal connective tissue or epidermal tissue. Vegetable capsules and gelatin capsules are almost the same in appearance. How do distinguish them? Regarding vegetable capsules and gelatin capsules, relevant persons have proposed relatively professional identification methods.

  (一) Identify and prepare samples according to pharmacopeia methods

  1. Identification of vegetable capsules and preparation of samples

    (1) Take 1g of the capsule, add 100mL of cold water (20 ~ 25 ° C), and continuously stir to form a viscous liquid; take 2mL and put it in a test tube, slowly add 1mL of 0.035% anthrone sulfuric acid solution along the tube wall, leave it for 5min, and place it in a test tube. A blue-green ring appears at the interface of the two liquids.

    (2) Take an appropriate amount of the viscous liquid under-identification (1) and pour it on a glass plate to evaporate the water to form a tough film.

  2. Identification of gelatin capsules and preparation of samples

    (1) Take 0.25g of this product, add 50mL of water, heat to dissolve, let it cool, take 5mL of the solution, add a few drops of potassium chromate test solution-dilute hydrochloric acid (4:1) mixed solutions to form orange-yellow flocculent precipitation.

    (2) Take 1mlL of the solution remaining in the identification (1), add 50mL of water, shake well, add a few drops of tannic acid test solution, and turbidity will occur.

    (3) Take 0.3g of this product, put it in a test tube, add a little soda lime, heat it, and the gas generated can make the wet red litmus paper turn blue.

  (二）dissolution phenomena distinguish two kinds of capsules

    Dissolving in cold water: Place the two capsules in 25C cold water, and the gelatin capsules will gradually expand without dissolving. The vegetable capsule dissolves gradually.

  (三） burning phenomena distinguish two kinds of capsules

    Burn the two capsules separately, the vegetable capsule produces the smell of burning cotton, and the gelatin capsule produces the smell of burning protein, similar to the smell of burning hair).

    Abstract: The inspection and identification methods of vegetable capsules and gelatin hollow capsules (hereinafter referred to as "gelatin capsules") are different due to the different raw materials used. This paper also compares the advantages of vegetable capsules and gelatin capsules in the application.