[Supercritical carbon dioxide; an efficient solvent for herbal extraction]

Supercritical fluid extraction [SFE] is an alternative to liquid extraction using solvents. Supercritical fluids can have solvating powers similar to organic solvents, but with higher diffusivities, lower viscosity, and lower surface tension. Carbon dioxide is the most commonly used supercritical fluid owing to its nontoxic, nonflammable, inexpensive, environmental friendly properties and mild critical conditions [Tc = 31.1 C° and Pc = 73.8 bar]. Due to the low heat of process and the relatively unreactive solvent used in the extraction, the fragrant compounds derived often closely resemble the original characteristics of the raw material. Like solvent extraction, extracts a wide range of compounds and leaves the aromatics unaltered by heat, rendering an essence more faithful to the original. In this review, some aspects of this etraction methods have been discussed

Chemical composition of the essential oil from aerial parts of Echinophora platyloba DC. from Iran

Essential oils and various extracts from plant are of great interests in the industry and scientific research. This study was designed to examine the chemical composition of essential oil and of Echinophora platyloba from Iran. The chemical composition of the hydrodistilled essential oil of the air-dried aerial parts of Echinophora platyloba growing wild in Iran was obtained by hydrodistillation and was analyzed by gas chromatography [GC] and gas chromatography-mass spectrometry [GC-MS]. The species is poor in essential oil [yield=0.7%]. Twenty-nine constituents representing 97.43% of total oil have been identified. The main constituents of the oil were found to be [Z]-beta-ocimene [26.71%], delta-3-carene [16.16%], Limonene [6.59%]. Other representative compounds were identified as Cis-3-hexylbenzoate [4.57%], Spathunenol [4.57%], Myristicin [4.48%], Myrcene [4.31%], 4-decanolide [4.2%] and alpha-Pinene [4.03%]. The oil of Echinophora platyloba consists of 16 monoterpenoids [69.55%] and 5 sesquiterpenoids [7.08%]

Chemical composition of the essential oil from leaves and flowering aerial parts of Psammogeton canescens [DC.] Vake from Iran

The genus Psammogeton Edyew. which belong to the umbelliferae family, is found in central areas of Asia. This genus consists of six species widespread in the sandy dunes of deserts. Among the four species present in Iran, Pssamogeton canescens [DC.] vatke is distributed in regions of Iran central. The aim of this study is to determine the chemical composition of essential oil of Psammogeton canescens. The essential oil was extracted by hydrodistillation of dried aerial part of plant and analysed by GC and GC/MS. Thirty constituents representing 99.7% of total oil have been identified. The main constituents of the oil were found to beta-bisabolene [33.35%], Apiole [28.34%], alpha-Pinene [11.86%] and Dill apiole [8.17%]. Other representative compounds were identified beta-Pinene [2.68%], Myrcene [2.62%] and sylvestrene [2.42%]. Amounting to 99.7% of the total oil, the sesquiterpene hydrocarbons and oxygenated sesquiterpene had the highest contribution [78.16%], these fractions dominated by micro sign bisabolene [33.35%], followed by Apiole [28.34%] and Dill apiole [8.17%]. The diterpene was very poor; it represented [0.49%], it is found to contain only a few percent of cembrene [0.49]

Precipitation of fluticasone propionate microparticles using supercritical antisolvent

The ability of supercritical fluids [SCFs], such as carbon dioxide, to dissolve and expand or extract organic solvents and as result lower their solvation power, makes it possible the use of SCFs for the precipitation of solids from organic solutions. The process could be the injection of a solution of the substrate in an organic solvent into a vessel which is swept by a supercritical fluid. The aim of this study was to ascertain the feasibility of supercritical processing to prepare different particulate forms of fluticasone propionate [FP], and to evaluate the influence of different liquid solvents and precipitation temperatures on the morphology, size and crystal habit of particles. The solution of FP in organic solvents, was precipitated by supercritical carbon dioxide [SCCO[2]] at two pressure and temperature levels. Effects of process parameters on the physicochemical characteristics of harvested microparticles were evaluated. Particle formation was observed only at the lower selected pressure, whilst at the higher pressure, no precipitation of particles was occurred due to dissolution of FP in supercritical antisolvent. The micrographs of the produced particles showed different morphologies for FP obtained from different conditions. The results of thermal analysis of the resulted particles showed that changes in the processing conditions didn't influence thermal behavior of the precipitated particles. Evaluation of the effect of temperature on the size distribution of particles showed that increase in the temperature from 40 °C to 50 °C, resulted in reduction of the mean particle size from about 30 micro m to about 12 micro m. From the results of this study it may be concluded that, processing of FP by supercritical antisolvent could be an approach for production of diverse forms of the drug and drastic changes in the physical characteristics of microparticles could be achieved by changing the type of solvent and temperature of operation

Comparison of super critical fluid extraction and hydrodistillation methods on lavander's essential oil composition and yield

Lavender's essential oil is commonly used in aromatherapy and massage. Its major clinical benefits are on the central nervous system. Linalyl acetate and linalool are the most predominant chemical constituents in the essential oil of Lavandula angustifolia Comparison of super critical fluid extraction [SCFE] and hydrodistillation [HD] methods on Lavander?s essential oil composition and yield methods In this work we extracted essential oil of this plant with two different methods; SCFE and HD and further analyzed by GC and GC-MS method. seventeen compounds were identified in the oil which prepared by HD, the major components of them were j. pinene [35.9%] and lavandulyl acetate [14.1%]. In the SCFE extracted sample, the most frequent components were linalyl acetate [73.5%] and lavandulyl acetate [7.5%]. According to obvious difference in the composition of the essential oils prepared by two different methods [SCFE and HD], it seems that extraction method differ chemical composition of the oil and probably affects pharmacological properties