Naslov
Interaction of salicylic acid with calcite

Autori
Ukrainczyk, Marko ; Kralj, Damir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
International School of Crystallization Abstract Book / Juan Manuel Garcia Ruiz - Granada : Laboratorio de Estudios Cristalograficos, 2009, 129-129

Skup
International School of Crystallization: Foods, Drugs and Agrochemicals

Mjesto i datum
Granada, Španjolska, 25.05.2009. - 29.05.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Precipitation; adsorption; calcite; salicylic acid

Sažetak
In recent years much attention have been devoted to the development of various drug delivery systems for controlled introduction and/or release of active organic substances in living organisms and tissues. Their application can also enhance drug stability and bioavailability or even target the drug to the specified cell or tissue as well. Although, the organic drug delivery systems are regularly used (e.g. liposomes, micelles etc.), some inorganic carriers have been recently developed and proposed for modulating drug delivery. In particular, calcium carbonate has potential use as mineral carrier of pharmaceutical substances due to its low cost, nontoxic properties and biocompatibility. The purpose of this work is to investigate the mechanism and extent of adsorption of salicylic acid, non-steroidal anti-inflammatory drug used as organic model molecule, on the calcite crystals of either, rhombohedral or scalenohedral morphology. The calcite crystal seed of rhombohedral and scalenohedral morphology have been prepared in precipitation system Ca(OH)2(s) – H2O(l) – CO2(g), which enables the preparation of high quantity of pure and well defined precipitate. Samples were characterized by means of FT-IR spectroscopy, scanning electron microscopy and surface area analyzer by the BET method of nitrogen adsorption. The adsorption of salicylic acid on calcite was studied using batch adsorption technique by means of UV spectroscopy and acoustic spectroscopy. In order to study the salicylic acid and calcite surface interactions, we investigate the effect of salicylic acid on the kinetics of calcite seed crystal growth. The precipitation process was followed by recording pH as a function of time. It was found that the extent of adsorption was higher at lower pH, which was explained to be a consequence of lower fraction of CO32- in solution at such conditions. The carbonate ions block the active sites on the calcite surface, thus competing with salicylate ions for the calcium sites on the calcite surface. However, the adsorption was found to be more pronounced on rhombohedral than on scalenohedral calcite, as a consequence of their different surface structure.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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