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Identifier

000373685

Title

Ελεγχόμενη αποδέσμευση φωσφονικών φαρμάκων ακινητοποιημένα σε κατιοντικές πολυμερικές μήτρες

Alternative Title

Controlled release of phosphonate pharmaceuticals immobilized on cationic polymeric matrices

Author

Πασπαλάκη, Μαρία Εμμ.

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Δημάδης, Κωνσταντίνος Κ.

Abstract

The present thesis deals with the development of a controlled release system which could be used in pharmaceutical applications. Specifically, we attempted to immobilize anionic phosphonates onto cationic polymeric matrices and, furthermore, we examined the rate of phosphonate release from these polymeric matrices. The anionic phosphonates HEDP (hydroxyethylidene-diphosphonate) and EDTMP (ethylenediamine-tetrakis (methylenephosphonate)) are prospective drugs for calcium deposition diseases and the cationic polymers PEI (polyethyleneimine) and PDC (poly(diallyldimethylammonium chloride)) represent the polymeric matrices. When the above phosphonates react with the polymers, a complex salt is produced which is formed due to the electrostatic interactions between the polycation and the phosphonate. After synthesizing such complexes in various pH regions, they were characterized by using FT-IR spectroscopy, the phosphorus content was determined and, finally, tablets containing the synthesized complex were prepared and placed in a solution similar to the stomach environment. Then we studied the release of the phosphonates every one hour for 8 hours. In order to determine the concentration of the phosphonate released we used the HACH method in which a blue complex is produced after the reaction of phosphates with ammonium molybdate. The higher the concentration is the more intense the blue colour is. We tried to succeed controlled and slow release of the phosphonates from the polymeric matrices. Not all the complexes succeeded our purpose but some of them did. Those were the complexes with PEI and HEDP. Finally, efforts were made to establish the controlled release by using ¹H and ³¹P NMR spectroscopy.

Language

Greek

Subject

Bisphosphonates

Drug delivery

Etidronic acid

Osteoporosis

Polyethylenic

Polymers

Διφωσφονικά

Ετιδρονικό οξύ

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