Capsules are a modern, unit dosage form. They contain the active substance released in the place of the gastrointestinal tract, where it is intended for the properties of the membrane.
Types of capsules and their shells
Capsules come in hard or soft shells consisting of gelatin, starch or polymer. Inside, a medicine can be enclosed in a variety of forms: paste, powder, liquid, granules.
Gelatin capsules are the most common type of capsule. Their predecessors were starch wafers. Gelatin capsules are easy to manufacture, dissolve well and safely in the body. But they have a number of disadvantages, such as fear of water, and they can also serve as a medium for the propagation of microorganisms. Polymeric shells also exist. They comply with safety indicators, dissolve well in an acidic environment. They also find demand among vegetarians, in contrast to gelatin capsules obtained from the connective tissue of vertebrates.
To improve the aesthetic appearance in the manufacture of shells, colorants approved for use may be added. Large pharmaceutical companies use many different shades, because the psychological factor of the drugs used by humans is known. The smell of the capsule is also corrected, this is achieved by adding essential oils and essences.
In addition to internal use, there are capsules for local action: rectal and vaginal, and there are sublingual ones. At the place of dissolution, the capsule shells are for swallowing, there are disintegrating in the environment of the stomach or in the small intestine.
Capsule use
Capsules have a wide purpose. Modern technologies make it possible to enclose in capsules, in addition to medicines, various nutritional supplements, for example, for sports nutrition, there are drugs for veterinary medicine, capsules for weight loss. There are capsules for cosmetic use, shell creams, bath products, aromatic oils.
For example, athletes add special amino acids to their diet to increase muscle mass. For convenience, instead of constantly diluting the powder of these additives, manufacturers enclose it in a capsule. Thus, they achieved the accuracy of the dosages taken, the convenience of transportation, the elimination of the unpleasant taste and smell of the powder, which eliminated the need to add unnecessary flavors and chemicals to improve the dissolution of powders in water.
Benefits of encapsulated dosage forms
Capsules are second most popular after tablets after all dosage forms. What are their advantages and features?
- Modern equipment allows to produce capsules with high accuracy and without loss of medicinal substance, and also allows you to paint in a different color and mark.
- The capsule hides the unpleasant taste and smell of the medicine.
- The shell reliably protects the drug from external adverse effects and reduces the addition of various stabilizers.
- Capsules quickly disintegrate in the body, a soft or powdery form of a drug substance is rapidly absorbed.
- There are drugs in which new pharmacological properties were discovered when they were enclosed in a capsule; instructions for the use of certain drugs, for example, make it clear that when they were enclosed in a capsule, they received a new method of use - as sleeping pills.
- The ability to set capsule shells with specific properties allows the creation of drugs with prolonged action or with protection against the effects of gastric juice, with dissolution in the small intestine.
The main differences from tablets
The main difference, in addition to appearance, is that in the manufacture of tablets, the manufacturer is forced to add various chemical binders to form the tablet, because not all drug powders are compressible.
Tablets that do not have incisions on the surface should not be divided before use. This is because the drug substance can be unevenly distributed inside. Therefore, tablets are not recommended to be divided for use in childhood due to a possible overdose. Also, a part of a divided tablet, which often has special components for better absorption, may have less therapeutic effect than its other part.
A capsule can only be opened and divided in very rare cases, especially for sealed capsules.
Pills can not only be swallowed, some of them need to chew or dissolve. But those tablets that are designed to be washed with water dissolve longer, since she still needs to go through many barriers of the gastrointestinal tract. In the capsule, the therapeutic substance is already crushed, when the shell is dissolved, it will immediately absorb and act faster.
How to take capsules
Today there is a wide variety of dosage forms, you need to know the general concepts about their use and carefully read the instructions. Replace yourself, for example, a tablet with a capsule or vice versa - not worth it. Since they can act in different ways or not at all.
Capsules enclosed in a special protective shell from the effects of gastric juice should act in the small intestine and dissolve only in its alkaline environment. The instructions for the use of capsules will indicate that it is impossible to open, otherwise the therapeutic effect is neutralized by the acid of the stomach, or completely harm its mucous membranes.
In order to make it easier to swallow the capsule, you can slightly moisten it with saliva in the mouth. And drink plenty of water.
Microcapsules
This type of capsule is an innovation in modern medicine. The microcapsule shell consists of a polymer. The medication enclosed may be a liquid, gas, or solid. The size of the microcapsule particles enclosed in the shell can be from 5 to 5000 microns, and their filling can be from 50 to 99%.
In addition to the general properties of capsules, microcapsules have a number of important advantages for pharmacy. Thanks to microencapsulation, it is possible to combine substances in a single dosage form, which in a free form would react among themselves.
The regulation of the thickness and porosity of the shell allows you to get a drug with slow release and longer duration. This allows you to increase the effectiveness and reduce the number of side effects of the drug. A good example is the new prolonged form of nitroglycerin, which is used to prevent angina attacks. Enclosed in microcapsules, he began to be released more slowly, and its effect increased to several hours.
Unstable in the free state, some enzymes, vitamins, antibiotics with microencapsulation become stable forms.
Can there be harm
The question of the dangers of capsules may concern people who are interested in the composition of their capsule. The gelatin shell is absolutely harmless to the body, it is non-toxic and is easily absorbed even with violations of the gastrointestinal tract. Manufacturers are constantly on the lookout for improved features, availability and safety. The capsule shell completely dissolves in the body and cannot be harmful. What can not be said about the opening of capsules, which are not intended for this.
Conclusion of the article
Pharmaceutical production is constantly being improved. In the same way, the methods of delivering drugs to our bodies are becoming more focused, perfect and safe. The capsule refers to those dosage forms that still go their way from a simple pouch to a drug that is quite technologically difficult. Which capsules are better, time will tell, but the fact that they are finding more and more use and are increasingly being introduced into medical practice is undeniable.