Cationic surfactants-modified natural zeolites: improvement of the excipients functionality.
BACKGROUND
In this study an investigation of cationic surfactants-modified natural zeolites as drug formulation excipient was performed.


OBJECTIVE
The aim of this work was to carry out a study of the purified natural zeolitic tuff with high amount of clinoptilolite as a potential carrier for molecules of pharmaceutical interest.


METHODS
Two cationic surfactants (benzalkonium chloride and hexadecyltrimethylammonium bromide) were used for modification of the zeolitic surface in two levels (equal to and twice as external cation-exchange capacity of the zeolitic tuff). Prepared samples were characterized by Fourier transform infrared spectroscopy, thermogravimetric, high-performance liquid chromatography analysis, and powder flow determination. Different surfactant/zeolite composites were used for additional investigation of three model drugs: diclofenac diethylamine, diclofenac sodium, and ibuprofen by means of adsorption isotherm measurements in aqueous solutions.


RESULTS
The modified zeolites with two levels of surfactant coverage within the short activation time were prepared. Determination of flow properties showed that modification of zeolitic surface reflected on powder flow characteristics. Investigation of the model drugs adsorption on the obtained composites revealed that a variation between adsorption levels was influenced by the surfactant type and the amount present at the surface of the composites.


CONCLUSIONS
In vitro release profiles of the drugs from the zeolite-surfactant-drug composites revealed that sustained drug release could be attained over a period of 8 hours. The presented results for drug uptake by surfactant-zeolite composites and the afterward drug release demonstrated the potential use of investigated modified natural zeolite as excipients for advanced excipients in drug formulations.
Krajisnik
Danina
D
Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia. danina@pharmacy.bg.ac.rs
Milojević
Maja
M
Malenović
Anđelija
A
Daković
Aleksandra
A
Ibrić
Svetlana
S
Savić
Snezana
S
Dondur
Vera
V
Matijasević
Srđan
S
Radulović
Aleksandra
A
Daniels
Rolf
R
Milić
Jela
J
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry; D001548:Benzalkonium Compounds / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D004008:Diclofenac / Q000031:analogs & derivatives / Q000737:chemistry; D005079:Excipients; D007052:Ibuprofen / Q000737:chemistry; D011208:Powders / Q000032:analysis / Q000737:chemistry; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001548:Benzalkonium Compounds; D002412:Cations; D002593:Cetrimonium Compounds; D005079:Excipients; D011208:Powders; D013501:Surface-Active Agents; D017641:Zeolites; D004008:Diclofenac; D007052:Ibuprofen; D000077286:Cetrimonium