ABSTRACT
ABSTRACT Centella asiatica (L.) Urb., Apiaceae, is commonly used as food, food supplement, and medicine. Development of the extraction process to obtain the high extent of the active compound is necessary. So, the response surface methodology was used in this work to optimize the dynamic maceration of C. asiatica to obtain the highest content of the four centelloids including asiatic acid, madecassic acid, asiaticoside, and madecassoside. Two factors: extraction temperature and extraction time, were studied. The content of four centelloids was observed. After the extraction of C. asiatica using ethanol, the content of four centelloids was analyzed using validated high performance liquid chromatography. The optimization result showed that madecassoside and asiaticoside had a similar pattern of the contour plots and response surfaces. These two centelloids were highly extracted at a high extraction time and high extraction temperature. The other two centelloids had the same pattern, they had a high content at a high temperature and time as well as at a low temperature and time. The simultaneous highest content of four centelloids was achieved when extracted at 60 °C for 120 min. The optimal condition could be used as standard condition for extraction of C. asiatica to provide the highest content of four centelloids.
ABSTRACT
ABSTRACT The objective of the work was to validate the high performance liquid chromatography for simultaneous determination of stability of madecassoside and asiaticoside in Centella asiatica (L.) Urb., Apiaceae, extract-loaded film forming polymeric dispersions. High performance liquid chromatography method was validated in five topics: linearity and range, limit of detection and limit of quantitation, specificity, precision, and accuracy. Results showed the method had a good linearity (R2 > 0.9990) in the range of 5-150 µg/ml and specific. The limit of detection and limit of quantitation of madecassoside were 81 and 245 ng/ml and asiaticoside were 21 and 64 ng/ml, respectively. The percent relative standard deviation of intraday and interday precision were less than 1 and 3%, respectively. The accuracy presented as percent recovery was 101.54-103.29% for madecassoside and 100.39-102.58% for asiaticoside. This validated high performance liquid chromatography method was used to determine the stability of the formulation containing Centella asiatica extract. Centella asiatica extract-loaded film forming polymeric dispersions used Eudragit® RS 30D and Eudragit® RL 30D as film former, glycerin as plasticizer, and absolute ethanol as solvent and penetration enhancer. Three formulations with different ratio of Eudragit® RS 30D and Eudragit® RL 30D were prepared and stored for 90 days at 4 ºC, 25 ºC, and 40 ºC. Stability results showed that almost all of the formulations were unstable at 25 ºC and 40 ºC. Except, two of three formulations were stable at 4 ºC. However, the formulation was further developed to improve the stability of madecassoside and asiaticoside in the formulation.