A New Approach to Enhance Bioavailability: Dosage Forms with Extended Residence Time in the Stomach

Berna TÜRKMEN*, Eda GÖKBULUT**, Nurten ÖZDEMİR*°

* Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100, Ankara, Turkey
** Nobel Pharmaceuticals, Tahran St. 6/6 Kavaklıdere, Ankara, Turkey

° Corresponding Author;
Tel: 0312 203 31 51
Fax: 0312 213 10 81
e-mail address: nozdemir@pharmacy.ankara.edu.tr

 

Summary

In recent years there has been an increase in studies aiming to enhance bioavailability by extending the residence time of active substances absorbed in the stomach and the upper part of the small intestine in the gastrointestinal system (GIS). From the studies conducted, it has been proved that the residence time of dosage forms in GIS can be extended and bioavailability can be enhanced by preparing high density systems, floating dosage systems, swelling and expanding systems, superporous hydrogel systems, mucoadhesive and bioadhesive systems, and magnetic systems. This article includes information on the classification of dosage forms that reside in GIS, which characteristics of active substances need to have for the preparation of these dosage forms, the factors impacting the residence time in GIS, the physiology of the GIS area, the gastric discharge procedure, gastric pH, and studies conducted on these issues.

Key Words :
Bioavailability, floating dosage forms, swelling systems, mucoadhesive systems, high density systems.