Capsules are just a kind of decoration or vest for medicines. Of course, it is not only used to make them look good, but also to make them easy to take and achieve the best effect.
According to historical records, the first capsule used by humans was created in Egypt 1500 years ago. At the time, it was not clear whether the capsule was purely for packaging medicine. However, since 1730, pharmacists in Vienna began to use starch to make what was then called vegetable capsules. At this point, it is obvious that capsules are used to pack medicines. This capsule production technology was patented in Paris in 1834.
The medicine taken when the patient is sick must be digested and absorbed into the blood through the gastrointestinal tract, and then decomposed by the liver. However, a considerable number of powders, granules, liquids, and tablets have bitter taste and irritation. They are volatile or are broken down by saliva in the mouth. Some drugs may also be inhaled into the airways and cause side effects. Therefore, putting the medicine in the capsule can protect the oral cavity and digestive tract, facilitate swallowing, and make the medicine play the best role.
And to get the best medicine, it is also important to prevent it from destroying a person's stomach acid, because some medicines need to be dissolved in the intestine and absorbed, so substances made of capsule-like special membrane materials (such as gelatin, cellulose, polysaccharides, etc.) ) Need to encapsulate various types of drugs, such as powders and liquids, according to the dose.
In addition, the drug has a half-life, which refers to the time required for the maximum concentration of the drug in the blood to halve. The half-life of a drug reflects the rate of excretion (excretion, biotransformation, storage, etc.) of the drug in the body, and reflects the relationship between the time of the drug in the body and the blood drug concentration. Therefore, it is the main basis for determining the dosage and frequency of administration. Drugs with a long half-life are slowly eliminated in the body with a longer interval of use, while drugs with a short half-life are eliminated quickly in the body with a shorter interval of use.
For drugs with a short half-life, frequent administration is required to maintain the concentration of the drug in the blood. In order to avoid the trouble of frequent dosing, special capsules are used to pack the medicines, which are called sustained-release capsules. Sustained-release capsules also avoid the shortcomings of frequent administration of non-patented preparations, which may lead to high and low effective blood drug concentrations, and have fewer toxic and side effects than non-patented preparations. Therefore, many drugs, such as ibuprofen, aspirin and Tylenol, can be formulated in DR capsules.