PharmD Info

Drug delivery experts use the words “encapsulation” and “entrapped efficiency” to refer to how well a delivery mechanism works at getting a medicine to its destination. Despite their similarities, they do not describe the same components of the drug delivery process and cannot be used interchangeably.

Encapsulation is the process of encapsulating a medicine in a carrier substance, such as a microsphere, liposome, or polymer nanoparticle. It can increase the medication's stability and bioavailability since the drug is physically confined within the carrier, shielding it from oxidation or removal by the body's defences. The amount of the medicine that is effectively encapsulated inside the carrier is known as the encapsulation efficiency.


On the other hand, entrapment efficiency describes the proportion of the medication that is really released from the carrier and administered at the target location. The characteristics of the carrier material, the size of the particles, the pace of medication release, and the environment at the target location all have an impact on this. A high entrapment efficiency does not always translate into a high delivery efficiency, since certain carriers may hold onto the medication for a long time while other carriers may release it too fast or inefficiently.

In summary, encapsulation and entrapped efficiency are both important considerations in drug delivery systems, but they describe different aspects of the process. Encapsulation efficiency measures the percentage of the drug that is successfully enclosed within the carrier, while entrapped efficiency measures the percentage of the drug that is actually released from the carrier and delivered to the target site.