The loading and release properties of gallic acid encapsulated in Crocus sativus pollen as a new microsystem

The main problem with the most plant pollens as oral delivery system is very low loading capacity and burst release pattern. In addition, for nutraceutical loading, it is necessary to open the aperture of pollen with acid and alkaline treatments. We hypothesized that in sterile pollen such as Crocus sativus, cracking may be easily performed due to the weakness of the exine and intine. Accordingly, saffron pollens were swollen in two solvents of water and ethanol, and gallic acid (GA) loading was performed under the ultrasonic and non-ultrasonic condition at two temperatures of ۲۵ ºC and ۳۵ ºC. SEM images showed that shaking pollen in water for ۲ hours has created some surface pores and cracks which allowed the drug to enter the pollen easily. HPLC and TGA analyses revealed the loading yield of ۷۵.۵% after this treatment, which has not been reported for any pollen, so far. The loading yield in ethanol was ۴۱.۸%. The loading yield in water and ethanol solvents, under ultrasonic conditions, were ۹.۵% and ۴.۶%, respectively. The SEM images showed deformation and destruction of pollen under water-ultrasonic and ethanol-ultrasonic conditions, respectively. The release content of GA in the stomach and small intestine condition during ۷۲ h were ۴۰% and ۳۵%, respectively. According to these results, we can strongly suggest the saffron pollen as a high potential for studying the oral delivery of various drugs and food additives.

Keywords:

Gallic acid , Crocus sativus. Pollen , Sporopollenin , Microencapsulation