Background:
Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin
belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release
tablets were found.
Objective:
The aim of this study was to find the influential factor of the crystal transition of clarithromycin
in preparation process of sustained-release tablets and to investigate the possible interactions
between the clarithromycin and pharmaceutical excipients.
Methods and Results:
The crystal transition of active pharmaceuticals ingredients from form II to form
I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction.
The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder
diffraction were used for assessing the compatibility between clarithromycin and several excipients as
magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline
cellulose. All of these methods showed compatibilities between clarithromycin and the selected
excipients. Alcohol prescription simulation was also done, which showed incompatibility between
clarithromycin and concentration alcohol.
Conclusion:
It was confirmed that the reason for the incompatibility of clarithromycin with high concentration
of alcohol was crystal transition.
