Capsules are simply a veneer or waistcoat for medicines, and are used not just to make them look good, of course, but mainly to make them easy to take and to achieve optimum efficacy.
According to historical records, the first capsules used by humans were created in Egypt 1500 years ago. At that time, it is not known whether the capsules were purely for the purpose of wrapping the medicine. However, from 1730 onwards, pharmacists in Vienna began to manufacture what were then called vegetable capsules from starch. At this point it is clear that capsules were used to encase medicines. And the technology for the production of capsules was patented in Paris in 1834.
The medicines taken when a person is ill have to be digested and absorbed into the bloodstream by the gastrointestinal tract and broken down by the liver. However, a considerable number of powders, granules, liquids and tablets either have a bitter and irritating taste, are volatile or are easily broken down by saliva in the mouth, and some drugs can also be inhaled into the airways, causing side effects. Therefore putting medication in capsules protects the mouth and digestive tract, is easy to swallow and allows the medication to work at its best.
And to get the best out of a drug, it is also important to avoid it being destroyed by a person's stomach acid, as some drugs need to be dissolved and absorbed in the intestines, so capsule-like substances made of special membrane materials (such as gelatine, cellulose, polysaccharides, etc.) are needed to encapsulate various types of drugs, such as powders and liquids, in doses.
In addition, drugs have a half-life, which refers to the time it takes for the maximum concentration of a drug in the bloodstream to be reduced by half. The half-life of a drug reflects the rate of elimination (excretion, biotransformation, storage, etc.) in the body and shows the relationship between the time the drug is in the body and the blood concentration. It is therefore the main basis for determining the dose and frequency of administration. Drugs with a long half-life are eliminated slowly in the body and are given at longer intervals, while drugs with a short half-life are eliminated quickly in the body and are given at shorter intervals.
For drugs with a short half-life, frequent dosing is required to maintain the concentration of the drug in the blood. To avoid the hassle of frequent dosing, special capsules are used to encase the drug, which are called extended-release capsules. Extended-release capsules also avoid the disadvantages of frequent dosing of generic formulations, which can cause high and low effective blood concentrations, and have fewer toxic side effects than generic formulations. Therefore, many drugs, such as ibuprofen, aspirin and Tylenol, are available in DR capsule formulations.
