Naslov
Interactions of salicylic acid derivatives with calcite crystals

Autori
Ukrainczyk, Marko ; Gredičak, Matija ; Jerić, Ivanka ; Kralj, Damir

Izvornik
JOURNAL OF COLLOID AND INTERFACE SCIENCE (0021-9797) 365 (2012), 1; 296-307

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
calcium carbonate; calcite; salicylic acid derivatives; crystal growth kinetics; adsorption; drug delivery

Sažetak
Investigation of basic interactions between the active pharmaceutical compounds and calcium carbonates is of great importance because of the possibility to use the carbonates as a mineral carrier in drug delivery systems. In this study the mode and extent of interactions of salicylic acid and its amino acid derivates, chosen as pharmaceutically relevant model compounds, with calcite crystals are described. Therefore, the crystal growth kinetics of well defined rhombohedral calcite seed crystals in the systems containing salicylic acid (SA), 5-amino salicylic acid (5-ASA), N-salicyloil-L-aspartic acid (N-Sal-Asp) or N-salicyloil-L-glutamic acid (N-Sal-Glu), were investigated. The precipitation systems were of relatively low initial supersaturation and of apparently neutral pH. The data on the crystal growth rate reductions in the presence of the applied salicylate molecules were analyzed by means of Cabrera & Vermileya's, and Kubota & Mullin's models of interactions of the dissolved additives and crystal surfaces. The crystal growth kinetic experiments were additionally supported with the appropriate electrokinetic, spectroscopic and adsorption measurements. The Langmuir adsorption constants were determined and they were found to be in a good correlation with values obtained from crystal growth kinetic analyses. The results indicated that salicylate molecules preferentially adsorb along the steps on the growing calcite surfaces. The values of average spacing between the adjacent salicylate adsorption active sites and the average distance between the neighbouring adsorbed salicylate molecules were also estimated.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA