%0 Journal Article
%T Preliminary Assessment of the Chemical Stability of Dried Extracts from Guazuma ulmifolia Lam. (Sterculiaceae)
%A Gisely C. Lopes
%A Renata Longhini
%A Paulo Victor P. dos Santos
%A Adriano A. S. Ara¨²jo
%A Marcos Luciano Bruschi
%A Jo£żo Carlos P. de Mello
%J International Journal of Analytical Chemistry
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/508945
%X We report the results of a preliminary estimation of the stability of the dried extract from bark of Guazuma ulmifolia Lam. (Ħ°MutambaĦħ), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature ( ) and humidity ( ). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract of G. ulmifolia. 1. Introduction The reasons for the determination of stability of pharmaceuticals are based on concern for public health. The World Health Organization (WHO) defines the stability of drugs and medicines as the ability of a pharmaceutical product to maintain its chemical, physical, microbiological, and biopharmaceutical properties within specified limits throughout the duration of product usage [1]. Several studies reported on the stability of drugs and medicines [2¨C4]. To the best of our knowledge, the number of stability studies of plant extracts is not the same [5¨C7]. Measuring the chemical stability of extracts is challenging because of their chemical complexity, which may include hundreds of different compounds. Moreover, the presence of enzymes such as glycosidases, esterases, or oxidases plays an important role in the breakdown of secondary plant metabolites. Assessment of the chemical stability of plant extracts, many of which are promising candidates for phytomedicines, plays an important role in the process of new drug development. A variety of environmental conditions, such as light, heat, humidity, and the freeze/thaw cycle, can significantly affect the chemical stability of drugs during storage and handling. Identification of stability-affecting factors facilitates the selection of packaging material and the definition of storage and handling conditions [8]. Guazuma ulmifolia Lam. (Sterculiaceae), popularly known as Ħ°MutambaĦħ, is a tropical American plant found from Mexico to southern South America. In the popular medicine of several Latin-American
%U http://www.hindawi.com/journals/ijac/2012/508945/