A Capsule is a dosage form common in day-to-day health management. It exists as a packaging or a gummy and soluble envelope. Capsules are mostly without taste and are used as coats for drugs of liquid or pasty form. It can be made up of gelatin, hydroxypropyl methylcellulose (HPMC), and starch. Those made from materials other than gelatin are known as vegetarian capsules. In Choosing a capsule, you should know which one is right for you. Capsules can be divided based on the origin into vegetarian and gelatin capsules.
Gelatin capsule shells are of animal origin. Gelatin capsules are made up of gelatin which can be hard or soft. They are made from the hydrolysis of collagen from cows, fish, or pigs. As a result of the low cost of production, gelatin capsules are often used. It rapidly dissolves and ruptures. Therefore, it has the potential for rapid drug release.
The gelatin used in making the capsules has a lot of health benefits for you. It aids digestion, protects joints, and helps reduce joint pain. It can also improve your sleep and cognitive functions. Gelatin capsules have a high degree of flexibility and are easier to formulate.
Vegetarian capsules are also called HPMC or starch-based shells. Unlike gelatin capsules, they are of plant origin. They consist mainly of cellulose. The cellulose type used in the vegetarian capsule is hydroxypropyl methylcellulose (HPMC). Vegetarian capsules are non-toxic and do not have potential health hazards when taken for prolonged periods.
Gelatin Capsules or Vegetarian Capsules
When choosing a capsule, the gelatin capsule type will be the best for you when considering factors such as the cost, dissolution rate, and mechanical stability. Gelatin capsule dissolves readily in your stomach, and the active ingredients are released to be absorbed. It has one of the best API dissolution rates. With high dissolution, drugs are readily available for absorption into your body. Choosing capsules made from gelatin will be the best for fast drug onset.
When the cost factor is the primary concern, gelatin capsules would be most appropriate for you. They are cost-efficient compared to other capsule types. This is why most manufacturers will choose capsules made from gelatin. Ingredients for HPMC capsules are about three to four times higher than gelatin.
It is important to note that capsules have to be mechanically strong enough to cope with stress. Gelatin capsules have higher mechanical strength compared to other capsule types. Capsules made from gelatin are much stronger than capsules of different materials. So, if you want a mechanically stable capsule, those made from gelatin have upper hands.
Vegetarian capsules are most suitable for consumers who do not take products of animal origin such as gelatin or have dietary restrictions preventing them from consuming animal products. Also, people who have issues related to religion may go for vegetarian capsules.
When considering the aspect of stability, and solubility choosing capsules made from cellulose (vegetarian capsules) would be the best. Vegetarian capsules are less hygroscopic, making them more stable than gelatin capsules.
Acid Resistant Capsules
Gelatin capsules, as well as vegetarian capsules, dissolve readily in the gastric juices in the stomach. Some medications become ineffective when hydrolyzed or released into the stomach. Acid-resistant capsules can pass through the stomach unaffected and dissolve in the small intestine. They are also called enteric-coated capsules.
The enteric coating protects them from hydrolysis when they pass through the stomach. The capsules are soluble when they pass through an alkaline environment. This is usually in the small intestine.
When to choose capsules with enteric coating
Enteric capsules are the best when choosing capsules for drugs that can irritate the stomach. Pharmaceutical capsules with enteric coating move through the stomach without upsetting the stomach walls.
Also, to choose capsules for drugs that are affected by gastric juices and enzymes, enteric capsules are mainly considered.
Enteric-coated capsules are used in time-sensitive medications. This is because they take a longer time (an hour or two) to dissolve. The empty capsules are usually made of gelatin or HPMC and have various HMPC or gelatin capsules sizes.
Continue reading: A Guide to Choosing the Right Capsule Size for Your Needs