Evaluation of the Intestinal Absorption of Maltol-Zn and Ethyl maltol-Zn Complexes in Rat

Zinc deficiency in man is characterized by skin lesion, alopecia and has been linked to growth retardation and mental disturbance. For supplementation purposes zinc is currently presented as its sulfate salt, from which uptake by the body is poor, necesseting the administration of high doses. This leads to a range of unpleasant side effects. In order to increase the bioavailability of zinc, several zinc complexes such as malthol-Zn, ethyl maltol-Zn have been designed and synthesized. The distribution coefficients (Kpart) of the complexes between 1-octanol and water (pH 7.4) were also determined. The intestinal absorption (I.A) of complexes and zinc sulfate was determined using Everted Gut Sac (E.G.S) method at different concentration of (0-1000μg/lit) zinc and different times (0-120 min).The results showed that, at the concentration of 800 μg/lit zinc and after 120 minutes, the absorption was reached to maximum for both complexes and zinc sulfate.
Zinc uptake from zinc sulfate, maltol-Zn and ethyl maltol-Zn complexes were 210, 220 and 235 μg/lit respectively. The higher zinc uptake from ethyl maltol-Zn complex may be attributed to its higher lipophilicity (Kpart = 0.18) than maltol-Zn complex ((Kpart = 0.5).
The results showed that, in spite of higher zinc uptake of ethyl maltol-Zn complex in comparison with zinc sulfate, statistically there is no significant difference between them. This investigation indicated that ethyl maltol-Zn complex could be considered as a suitable zinc complex for the treatment of zinc deficiency in replacement of zinc sulfate.