Why some medicine come in capsule form?

  Some medications come in capsule form, because the nature of the substance makes it difficult or impossible to manufacture in a tablet form. Creating a tablet requires finding a binding material that allows the medication to be formed into a solid shape but that does not affect its chemical composition nor its bio-availability. For example, the typical aspirin tablet is held together mostly by corn starch.

  Some medications come in capsule form, because many consumers have a distinct preference for capsules. Many consumers perceive capsules as easier to swallow. Some consumers perceive capsules as more effective.

   An interesting example of the preference for capsules is provided by a study ("Effect of Shape of Medication in Treatment of Anxiety States") published in 1972 in the British Journal of Psychiatry by psychiatrist M. Z. Hussain, who found that patients being treated for anxiety responded better to treatment with the same drug (chlordiazepoxide) in capsule form rather than tablet form. There is no known medical reason for this, but its psychological significance is compelling. Capsules have been the required form for most clinical trials of psychiatric medications since 1972.

  Also some reason in capsule form because:-

       1. The nature of chemical substance. 

       2. Rapid bio availability rather than tablet.

       3. Easy to swallow for older and child patient. 

       4. Easy to manufacture where tablet need to more step.