Characteristics, Stability and Activity of Epigallocatechin Gallate (EGCG)-Chitosan Microspheres: Effect of Polymer Concentration

Abstract

Epigallocatechin gallate (EGCG) is a natural product compound which has known to have anticancer activity. However, its bioavailability was low of 0.1% limited by poor stability. This study was aimed to produce microspheres as drug delivery system to improve the stability of drug. EGCG-Chitosan microspheres were formed by ionotropic gelation-aerosolization technique and were produced from chitosan and sodium tripolyphosphate. This study evaluated effect of 1, 2 and 3% of chitosan concentration on physical characteristics, stability and activity of EGCG-Chitosan microspheres. Physical characteristics were evaluated in terms of particle size, morphology, moisture content, entrapment efficiency, drug loading, yield, swelling index, physical stability and activity. Stability was evaluated by measuring size, entrapment efficiency and drug loading at 25°C and 50°C temperature for storage period of 7, 14, 21 and 30 days. Activity test was evaluated with MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay using HeLa cells. Particle sizes of formula were 2.29, 2.68, and 3.11 µm respectively with entrapment efficiency of 33.94, 52.27, 62.14% and drug loading of 23.25, 29.36, and 32.24 % correspondingly. Morphology was spherical with smooth surface. Yields were 78.25, 79.36, and 79.77% respectively. No significant differences between all formulas indicated that microspheres were stable during storage. Activity results showed that formula with chitosan 3% was the most active as anti-cervical cancer showing by IC50 was 83.58 µg/mL. EGCG-chitosan microspheres demonstrated potential as drug delivery system and as anti-cervical cancer.