An in vitro methodology was developed to investigate the passive diffusion of Ca2+ ions across different membranes. Different natural mineral clays (bentonite, clinoptiolite, mordenite) were investigated to find the best model material which can be used as Ca-reservoir in form of patches applied on human skin and which can be an alternative for calcium supplementation in medical treatment of osteoporosis. The bentonite from Istenmezeje, a mineral clay with a great cation exchange capacity (CEC = 2450 meq/kg) enriched with Ca2+ in its layers proved to be the best Ca-supplying material. Building a simple permeation cell and using an AAS spectrometer it was possible to determine and to measure the Ca2+ concentration in the collected fractions. Matrix effects of the physiological saline solution were taken into consideration when Ca2+ concentrations were measured and various factors affecting the passive transdermal diffusion of Ca2+ were studied: temperature, the bentonite applying method, the quality and quantity of the enricher and the quantity of bentonite applied on the pig skin surface. The obtained results underlined the importance of this kind of in vitro experiments, which represent the first step in elucidation of the effect of different parameters influencing the local transdermal introduction of calcium from bentonite patches, envisaging the possibility of using the method for the treatment of osteoporosis. Using Bernard-type pulsate currents for delivering Ca2+ through pig skin further experiments (part II of present article, under preparation) were performed in order to determine the physical and chemical parameters governing ion transport during iontophoresis for a local therapeutical effect. Moreover, the effects of the combination of transdermally introducing calcium therapy with oral administration of calcium replacing drugs to a number of volunteers will be presented.
|Number of pages||8|
|Journal||Magyar Kemiai Folyoirat, Kemiai Kozlemenyek|
|Publication status||Published - aug. 1 2002|
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