IPDAS®
 | IPDAS, Intestinal Protective Drug Absorption System, was initially developed as part of the development process for Elan’s proprietary naproxen formulation, Naprelan®. The objective was to develop a once daily controlled release system that would have a fast onset of action and reduced gastric irritancy. IPDAS can also be employed to confer the advantages of multiparticulate technology, in a tablet dosage form. IPDAS is composed of numerous high density controlled release beads, which are compressed into a tablet form. |
| The method of manufacture for the multiparticulates can vary depending on the active ingredient loading and the required controlled release profile. Techniques such as extrusion/spheronization are employed and controlled release can be achieved with the use of different polymer systems incorporated into the resultant multiparticulate. |  . |
Another possibility is to coat the active ingredient onto an inert carrier such as non-pareil seeds to produce instant release multiparticulates. Controlled release can be achieved by the formation of a polymeric membrane onto these instant release multparticulates.
If a fast onset component is required, a portion of drug may be added as an immediate release component, either in the form of and instant release granulate as with the Naprelan formulation, or as instant release multiparticulates prepared as described above, without the incorporation of controlled release polymers.
Once an IPDAS tablet is ingested, it rapidly disintegrates and disperses beads containing a drug in the stomach, which subsequently pass into the duodenum and along the gastrointestinal tract in a controlled and gradual manner, independent of the feeding state.
 | Release of active ingredient from the multiparticulates occurs through a process of diffusion either through the polymeric membrane and or the micromatrix of polymer/active ingredient formed in the extruded/spheronized multiparticulates. The intestinal protection of IPDAS is by virtue of the multiparticulate nature of the formulation, which ensures wide dispersion of irritant drug throughout the gastrointestinal tract |
Naprelan, which is marketed in the United States, employs IPDAS technology. This innovative formulation of naproxen sodium is a unique controlled release formulation indicated both for acute and chronic pain.