BRPI0903275B1 - ARTEMISININ EXTRACTION AND PURIFICATION PROCESS FROM ARTEMISIA ANNUA SOLID MASS USING CARBON DIOXIDE - Google Patents

Abstract

process of extracting and purifying artemisinin from solid mass of sagebrush using carbon dioxide a process of extracting and purifying artemisinin from solid mass of sagebrush annua using supercritical carbon dioxide is described comprising at least (i) one first extraction step, which consists of a contact and dissolution of the particulate solid mass by supercritical co2 in an extractor (e1) obtaining co2 and dissolved plant drug; (ii) a second purification step consisting of a contact between co2 and dissolved plant extract with a fixed polar phase in a fractionating column (fi); and (iii) a third elution step consisting of a contact between a mixture of co2 and co-solvent with a fixed polar phase in the fractionating column (f1); (iv) the extractor (e1) and the fractionating column (f1) being arranged in a line in the same circuit. it is also described a pharmaceutical composition comprising containing artemisinin as the active principle from this process described in this invention; and b) a physiologically acceptable vehicle for treating malaria.

Description

The present invention relates to a process for extracting and purifying artemisinin from Artemisia annua using supercritical carbon dioxide.

The present invention further relates to a pharmaceutical use of the refined Artemisia annua extract obtained and purified from the process using supercritical carbon dioxide and to pharmaceutical compositions comprising said extract.

Description of the state of the art

Supercritical technology exploits the high densities (close to those of liquids) presented by supercritical fluids, associated with intermediate values of diffusivity (between gases and liquids) and low viscosities (characteristics of gases). These properties favor high extraction rates due to the great solvation power attributed to higher density values, while low viscosity values, associated with high diffusivity values, provide high penetration power 20 in the solid matrix [Yoda, SK Study of the kinetics of extraction of glycosides from Stevia reubadiana Bertoni with a CO2 + water mixture. 2001. 202p. Thesis (Masters in Food Engineering). Faculty of Food Engineering, State University of Campinas].

In the process of supercritical extraction in solid matrices, the supercritical fluid flows through the fixed bed (of solid particles) and solubilizes the compounds existing in the solid matrix, with the solvent being fed into the extractor and uniformly distributed inside the fixed bed. During extraction, the solid matrix absorbs the supercritical solvent, expanding the cell structure, promoting a decrease in the resistance to mass transfer and the extractable compounds are dissolved by the solvent and transferred by diffusion to the external surface of the particles. They are then transported by the fluid, and at this location, there may be changes in the state of aggregation, then they are removed from the extractor by the flow of the solute/solvent mixture. [Brunner, G. Gas extraction: An introduction to fundamentals of supercritical fluids and the 5 application to separation process. Darmastadt, Germany, Steinkpff; New York; Springer, 1994, pp.387].

Extraction with supercritical fluids promotes high mass transfer rates at relatively low temperatures, a fundamental characteristic for choosing this technique for extracting natural products (essential oils, 10 oleoresins, dyes and other active principles, etc.) in which the quality The final product is of great importance [Kiran, E., Brennecke, JF, Supercritical fluid engineering science: fundamentals and application. ACS, 1993, pp. 410].

The supercritical extraction technology has advantages when compared to conventional extractions, with organic solvents, related to 15 regulatory issues: environmental protection; these types of solvents have been banned by several countries; Extremely low residual concentrations are required in food products (the list of allowed solvents with food restrictions and the maximum level allowed in the final product can be found in the “Extraction Solvent in Foods” (Amendment Regulations. 1998 20 No 2257, ISBN 0 11 079579 2). Furthermore, supercritical technology is associated with the differentiated quality of the final product (high-value products such as food supplements, nutraceuticals, characterized as “natural” by the mode of preparation) [Perrut, M. Supercritical fluid application: industrial development and economic issues, Ind. Eng. Chem. Res., 2000, 39, 4531-4535], 25 According to Meireles [Meireles, MAA Supercritical extraction from solid process design data (2001-2003), Current Opinion in Solid State and Materials Science. 2003, 7, 321-330], when comparing the processes for obtaining natural extracts, the functional properties and quality of the extracts obtained should be taken into account. or different extraction technologies. Supercritical extraction certainly has an unfavorable investment cost compared to other technologies such as hydrodistillation (obtaining volatile oils) or any other low pressure solvent extraction process (LPSE). Even taking into account the number of associated unit operations that are not required by supercritical extraction (ESC) such as decantation, centrifugation, removal of the extract solvent and solid sludge (bagasse, exhausted material) which involves distillation, evaporation, decolorization , etc., ESC costs still higher. When the properties and quality of extracts obtained by different processes are compared, it is that ESC becomes competitive and becomes an option in the selection of an extraction process.

It is known in the state of the art that supercritical fluid extraction has been used in the extraction of different kinds of substances, 10 subsequently applied commercially.

Document JP 02235997 refers to the use of supercritical technology for the preparation of seaweed, vegetable flavors, and extraction/separation of organic compounds from grape skins.

Document ES2103238 uses a mixture of carbon dioxide at high pressure (50 to 500 bar) and solvents such as water, hydrocarbons, alcohol, ketone, ether in proportions of less than 50%, where the novelty is in the use of a mixture in the which solvent is not in supercritical condition due to the large proportion of water or ethanol present.

Document CN1253951 mentions the use of the supercritical fluid extraction process to separate and purify vitamin E with a pressure of 10 to 26MPa and a temperature of 25-55 °C.

Document W02005044829 refers to a silicone purification process for use as a contact lens using supercritical fluid with a density between 0.2 and 0.8 g/ml. In that case, soluble solids (impurities) are transferred to the solvent phase.

US 2005/0142231 describes a method of isolating and purifying compounds from five plants that have hypoglycemic activity using super/subcritical carbon dioxide by adjusting the process conditions. The pharmacological study of the compounds showed hypocholesterolemic activity, showing that they can be used to treat atherosclerosis and obesity.

The document US 5,120,558 deals with a method of extraction and fractionation of plant extracts using supercritical fluid extraction and fractionation with subsequent steps with separators with reduced pressures (subcritical).

Document US 6,685,972 deals with a process of extraction and purification of artemisinin. The extraction of soluble compounds from Artemisia annua is carried out by percolation with a non-aqueous polar solvent (ethanol) for 4 - 10 6 hours, at a temperature of 20 to 50 °C. After this first step the extract is concentrated and followed by the purification step. Purification of artemisinin is carried out by a sequence of solvents (water and organic solvent such as hexane). The hexane solution is concentrated and then ethyl acetate is added to the solution containing a reduced amount of hexane to initiate the crystallization of liquid artemisinin, through slow evaporation. For the removal of pigments, an adsorbent agent from the celite group was used, activated carbon, then the solution was filtered. The mild conditions used for extraction result in a clean extract and prevent artemisinin degradation.

US 4,992,561 describes the production of artemisinin from artemisininic acid. Artemisininic acid is reduced to dehydroepideoxyartenuin-B acid by diluting the acid in methanol with NiCl, adding NaBH4 or LiBH4. The solution is acidified and the dehydroepudeoxyartenuin-B is isolated. The dehydroepideoxyartenuin-B, from two successive steps, a photosensitive solution with an organic solvent such as acetone or methylene hydrochloride, followed by a halogenated solvent or a hydrocarbon followed by contact with atmosphere, forming artemisinin.

Document US 4,952,603 refers to a process for obtaining substantially pure artemisinin by extracting Artemisia annua with hexane and fractionating the hexane, acetonitrile and water mixture through a chromatographic column (silica gel). Crystallization of artemisinia is carried out by mixing ether and hexane and hexane and dichloromethane.

Document US 6,180,105 refers to a process using liquid carbon dioxide to obtain artemisinin from Artemisia annua. The final extract obtained contains less than 10% (by mass) of artemisinin without the presence of residual solvent. The extraction pressure range comprises between 100 - 310 bar, preferably 100 bar (1500 psi) and temperature in the region between 20 - 50 °C, preferably 25 to 30 °C, using a mixture of liquid carbon dioxide and a solvent hydroxylic polar such as ethanol. The percentage of ethanol co-solvent was varied between 5-20% and 10%, keeping the pressure constant at 100 bar.

Document US 5,955,084 deals with a process that uses hexane to extract artemisinin from Artemisia annua. Fractionation is carried out with a mixture of solvents between hexane and acetonitrile/water. The residue of the hexane fraction is hydrodistilled to obtain the essential oil. The extract contained in the acetonitrile phase is extracted with a hexane-benzene mixture. The solvent is removed and the extract dissolved in chloroform. A base is added to the solution to extract the chloroform solution. The aqueous base solution is then neutralized. The compounds of interest are extracted from the solution neutralized with chloroform and then the chloroform is evaporated and the extract is crystallized with a mixture of hexane-benzene to produce artemisininic acid. Artemisininic acid is reduced through photooxidation. Through silica gel chromatography, the acetonitrile phase is fractionated with hexane. The solvent is evaporated and finally the fractions enriched in artemisinin are obtained.

Document CN1680388 presents a methodology for extracting artemisinin using 60 to 70% solvent, regulating the pH between 7.5-8.0, thus depositing impurities.

The document PI9804730-2 describes a classical extraction process (96° Gl_ ethanol solvent) and serial extraction, so that the solutions obtained in these two processes are treated with activated carbon for approximately 1.5 hours at room temperature, and then filtered over diatomaceous earth, obtaining a solution to which precipitated silica was added. The solvent is distilled and the solid obtained called “farofa” is placed in an extractor adapted with a mechanical stirrer. The elution of this "crumb" with hexane and subsequent 15% (v/v) hexane/ethyl acetate in filtration with a column packed with silica (ratio of column diameter and height of silica column: 1:1.5) allowed to obtain a fraction enriched with artemisinin being subsequently treated with activated charcoal for 1.5 hours at room temperature, and then filtered over diatomite earth. The solution is concentrated to 5% of the initial volume. The suspension obtained is then crystallized under cooling (0 to 5 °C) for approximately 2 hours and then vacuum filtered and washed with a 15% hexane/ethyl acetate mixture previously cooled, this filtrate is then dried at 40 °C C for 8 hours. Artemisinin is obtained as a white solid in 0.9% yield (mass of artemisinin per mass of Artemisia annua raw material) with 91% purity. For the classic extraction process followed by purification and crystallization, 27.8 L of solvent is used, including ethanol, hexane and ethyl acetate, and for the series process, 10.3 L per kg of dry raw material is used.

Document FR2706166 deals with a process that uses supercritical extraction with carbon dioxide with pressure ranging from 60 to 500 bar and temperature ranging from 10 to 100 °C preferably 280 bar and 50 °C with the possibility of using a co-solvent (modifier) with pressure ranging from 150 to 300 bar and temperature ranging from 30 to 80 °C with preferably 20% (m/m) of ethanol. The yield of Artemisia annua total extract was 4.33% (m/m) with artemisinin content in the extract (m/m) of 3.72%, and the yield of artemisinin per raw material used was 0 .16% (mass of artemisinin per mass of Artemisia annua).

Document DE10336056 makes reference to a high pressure extraction process with carbon dioxide (60 - 85 bar) and a temperature of 20 - 50 °C, particularly with the presence of a modifier, specifically ethanol (2 - 20%), to obtain of artemisinin from Artemisia annua. The best extraction condition was with 10% ethanol, 90% carbon dioxide with a density of 0.79 g/mL. Extractors of 4L capacity were used, whose total extraction yield was 8%, containing 0.15% of artemisinin, therefore yield in artemisinin of 0.012%. After extraction, impurities and precursors of artemisinin are separated from the extract and artemisinin is isolated through purification in a chromatographic column and subsequent recrystallization.

Through supercritical extraction using carbon dioxide (75 to 400 bar and 30 to 50 °C), the maximum yield in total artemisinin under the operating conditions studied was 0.7% (bs) and the content of artemisinin in the total extract was 12.1% (m/m). In the initial part of the extraction (5% of the total extraction time for total bed depletion) an extract with a content of 17.9% (m/m) of artemisinin in the extract was obtained. [Quispe-Condori, S., Sanchez, D., Foglio, MA, Rosa, PTV, Zetzl, C., Brunner, G., Meireles, MAA, Global yield isotherms and kinetic of artemisinin extraction from Artemisia annua L leaves using supercritical carbon dioxide, J. Supercr. Fluids., 2005, 36, 40-48].

Still, the state of the art is aware of the interest in the preservation or packaging of the plant extract through Artemisia annua extract capsules, as shown by documents WO9920289-A; WO9920289-A1 and AU9896162-A. These documents present the alternative of encapsulating natural extracts with, for example, Artemisia annua extract capsule, among others, obtained via supercritical extraction with carbon dioxide by adding soybean oil (forming a solution) and then being encapsulated.

As can be seen in the prior art documents described above, the extraction and purification processes already known use organic solvents that are notably toxic in their steps, in addition to being impractical and costly processes. Furthermore, the processes already known in the state of the art have artemisinin content in the extract and artemisinin yield lower than that given by the present invention

Thus, from the description of the present invention below, it can be concluded that a process of extraction and purification of artemisinin from Artemisia annua using supercritical carbon dioxide, constituted by an adsorption column, is not known in the prior art and an extraction column arranged in series, making it possible to carry out these two steps in a single process. The process object of this invention does not use toxic solvents, in addition to being practical, as it allows the coupling of different industrial steps in a single continuous or semi-continuous process. In addition, the artemisinin extract obtained from the process described herein has an active mass content greater than 34.9% (equivalent to a content nine times higher than that reported by patent FR2706166-A1 and twice that reported by Quispe -Condori et al, 2005).

Objectives of the invention

The present invention aims to provide a process for obtaining a fraction substantially enriched in artemisinin from Artemisia annua using supercritical carbon dioxide.

It is also the aim of this invention to provide a pharmaceutical use for the enriched fraction of Artemisia annua extract obtained and purified from the process using supercritical carbon dioxide.

Furthermore, it is the aim of the present invention to provide the use of Artemisinina annua extract in the preparation of pharmaceutical compositions.

Brief description of the invention

The invention has as its object a process of extraction and purification of artemisinin from the solid mass of Artemisia annua using supercritical carbon dioxide comprising at least: (i) a first extraction step consisting of a contact and dissolution of the solid mass particulate by Supercritical CO2 in an extractor obtaining CO2 and dissolved plant drug; (ii) a second adsorption step consisting of a contact between CO2 and dissolved plant drug with a fixed polar phase in a fractionator column; and (iii) a third elution step consisting of a contact between a mixture of CO2 and a co-solvent with a fixed polar phase in the fractionating column; (iv) the extractor and the fractionating column being arranged in line in the same circuit.

This invention also has for its object a pharmaceutical use of the enriched fraction of the Artemisia annua extract obtained from the process described above and pharmaceutical compositions comprising said extract.

Brief description of figures

Figure 1 illustrates a flowchart of artemisinin extraction and purification process from Artemisia annua solid mass using supercritical carbon dioxide; Figure 2 illustrates the structural formula of artemisinin; Figure 3 illustrates the artemisinin pattern chromatogram; and

Figures 4a - 4f illustrate the chromatograms of the refined Artemisia annua extracts containing fractions enriched in artemisinin, obtained by the process described in this invention.

Detailed description of the invention

According to a preferred embodiment and as can be seen in figures 1, 2, 3 and 4a - 4f, the present invention relates to a process for extracting and purifying artemisinin from the solid mass of Artemisia annua using carbon dioxide supercritical (CO2); a pharmaceutical use of the enriched fraction of Artemisia annua extract; and pharmaceutical compositions comprising said extract.

The process described here presents a number of advantages when compared to the processes already known in the prior art for the extraction and purification of Artemisia annua: - With the introduction of a fractionating column (F1) in series with an extractor (E1), the steps of extraction and adsorption/elution are carried out in the same circuit, with or without the addition of modifiers, in an enriched fraction of Artemisia annua extract containing enriched artemisinin fractions; - Practical process (few steps), low cost (grade equipment low in sophistication) and does not use toxic organic solvents; - Residues and solvents covered during the steps of this process are classified as “GRAS” (Generally recognized as safe\,- The extraction environment (circuit) is completely hermetic, allowing to obtain refined extracts of Artemisia annua with the minimum potential of oxidation; - The process allows the extraction of the desired substance at mild temperatures (30 to 70 °C); - The process is versatile (continuous or semi-continuous), being able to couple in its circuit more than one extractor, fractionating column and separator; - The process avoids some types of degradation common to plant drug extraction processes, for example, in the process of hydrodistillation or steam distillation, hydrolysis of the extract occurs; - Enriched fraction of the Artemisia annua extract obtained from the object process of this invention comprises a content greater than 34.9% by mass of artemisinin. Process of extraction and purification of solid mass of Artemisia annua:

The process of extraction and purification of artemisinin from solid mass of Artemisia annua using supercritical carbon dioxide, object of the present invention, comprises at least: (i) a first extraction step consisting of a contact and dissolution of the particulate solid mass by supercritical CO2 in an extractor (E1) obtaining CO2 and dissolved plant drug; (ii) a second adsorption step consisting of a contact between CO2 and dissolved plant drug with a fixed polar phase in a fractionating column (F1); and( iii) a third elution step consisting of a contact between a mixture of CO2 and co-solvent with a fixed polar phase in the fractionating column (F1); (iv) the extractor (E1) and the fractionating column (F1) being arranged in line on the same circuit.

In more detail, the preferred embodiment of this process comprises the steps: - System loading: The extractor (E1) is fed with solid particulate mass of Artemisia annua, for example, leaves, stems or roots. The fractionating column 5 (F1), which is in series with the extractor (E1), is packed with the adsorption material such as silica or alumina. - Solvent feeding system: The pump (B1), fed with Liquefied carbon dioxide at -15 and -10 °C from a tank (T1) is used to raise the system pressure to a range between 60 and 400 bar, preferably 100 bar. In one of the following steps, as described in Example 6, a compressor (C-3) is fed with, for example, pressurized synthetic air from the tank (T3) with a pressure equal to or greater than 55 bar or pressurized nitrogen from the tank (T3) with a pressure equal to or greater than 40 bar, both examples, pressurized gases.

The pump (B2), fed with ethanol from a tank (T2), is used to displace the solvent and promote the pressurization of the system, equaling the pressure of carbon dioxide. - Extraction step: A possible configuration of this step comprises a CO2 solvent pressurized by the pump (B1) flows into the valve system (V1 20 and V4). The carbon dioxide then passes through the solid particulate mass of Artemisia annua that is housed inside the extractor (E1) and solubilizes the solutes according to the operating condition (preferably temperature of 30 °C and pressure of 100 bar) for 1 to 60 minutes, preferably for 10 minutes, without carbon dioxide flow through the extractor outlet valve (V7) 25 (static period). After this period, the flow of CO2 through the valve through the extractor (E1), valve (V7), fractionating column (F1) and separator (S1) and valve (V8) is allowed, preferably, but not restricting, following the example below, the ratio of mass of carbon dioxide used by solid particulate feed mass equal to 96.22 (kg/kg). During this period, the extraction and purification step30 take place simultaneously and the extract is collected in the collector (C1). - Purification step: In this step, the extraction solvent (supercritical carbon dioxide) from the tank (T1) passes through valve (V1), pump (B1), valve (V4), extractor (E1). Upon discharge from the extractor (E1), the mixture composed of the solvent (supercritical carbon dioxide) and the dissolved vegetable drug passes through the valve (V7), fractionating column (F1) and then through the separator (S1). In the fractionating column (F1) arranged in series with the extractor (E1), the dissolved plant extract comes into contact with the fixed polar phase, for example, silica. At that moment, when the hydrophilic components come into contact with the adsorption column, as in the case of artemisinin, they are retained on the surface of the fixed polar phase. The extraction solvent serves as the mobile phase in the artemisinin elution step. Carbon dioxide, an extract containing hydrophobic components that were not retained in the fixed polar phase of the fractionating column and co-solvent, if any, are directed to an S1 separator and then to a collector (C1).- Elution step: In this In this step, the F1 fractionator column is fed with a mixture of polar co-solvent and CO2, such as ethanol contained in tanks T2 and T1 respectively, through the simultaneous operation of pumps B1 and B2. Thus, the CO2 from tank T1 goes through valve V1 and is pressurized in pump B1 to operating pressure, goes through valve V5, enters mixer M1 for homogenization with the ethanol co-solvent that comes from tank T2 that initially leaves from tank T2, passes through valve V2, is pressurized to operating pressure B2, passes through valve V6 to 0 mixer M1. The mixture of CO2 + ethanol passes through valve V10 and feeds the fractionator column F1. The solvent feed system (CO2 + ethanol) in the F1 fractionator column follows a gradient (% ethanol) of 0, 1, 3, 5 and 10% (m/m). Between each step called elution within the fractionating column F1 the system is depressurized and a fraction is obtained in collector C2 after the separation step S1 as described below in the separation step. Then, the fractionator column F1 is fed with 100% (m/m) of ethanol (preferably in a 3:1 ratio of ethanol/silica) through the exclusive operation of Pump B2 operating at atmospheric pressure (valves V1 and V5 are kept closed and the B1 pump inoperative). After this “washing” step of the fractionator column F1 with 100% ethanol, valve V2 is closed and pump B2 is turned off. An inert pressurized gas, such as synthetic air or nitrogen, from tank T3 passes through valve V3, is pumped through compressor C3 into fractionator column F1 for complete removal of ethanol + "recovered" enriched fraction in collector C2 after passing through separator S1 and valve V10. The pressurization of the adsorption column starts again with the simultaneous supply of solvent, with the percentage of co-solvent being higher, according to the gradient presented above. This fractionator elution step uses a mass ratio of carbon dioxide by mass of silica equal to 79.19 and preferably the ethanol gradient is 0 and 1% (m/m).- Separation step: The extract fractions solid mass of Artemisia annua pass through the S1 separator. The step of separating carbon dioxide and ethanol (in the case of using a modifier) with extracted natural compounds is carried out by depressurizing the carbon dioxide, which passes to the gaseous state and loses its solvating power. Separator pressure may be in the range of 1 to 40 bar. The enriched fraction passes through valve V8 in the extraction/adsorption step or V11 in the elution step and is collected in collectors C1 and C2, respectively. Carbon dioxide is collected through valve V9, passing through condenser L1 and stored in tank T1 for later reuse.

Preferably, after the extraction step as described above, the E1 extractor is unloaded and re-fed. The F1 fractionator column whose silica is partially recovered at the end of the elution step must go through a full recovery step (removal of contaminating compounds) and is ready for the next cycle, since the recovery of the silica is total.- Concentration step: The polar organic co-solvent used must be removed from the fractions enriched with hydrophilic components (artemisinin, among others) using vacuum evaporators, preferably.

The process object of the present invention can be continuous, for this, a larger number of extractors and fractionators is required so that they are used in sequence, so that, while the line stops (E1 and S1 exhausted), another line (E2 and S2) is prepared with particulate vegetable mass and the separator is ready for a new extraction/adsorption/elution cycle. Preferably, if the process is continuous, the equipment should contain at least two extractors, two fractionators and two separators. - Quantification of artemisinin present in the fractions collected in collectors C1 and C2:

The samples were analyzed by gas chromatography with a flame ionization detector (CG-FID, Shimadzu, model 17A, Japan) equipped with a DB-5 capillary column (30m x 0.25mm x 0.25um, J & W Scientific). Carrier gas was helium (1.7 mL/min, 99% purity); 1:30 split. Injector and detector temperatures were 240 °C and 280 °C, respectively. The column was held at 50 °C for 5 minutes, followed by a ramp of 5 °C/min to 280 °C, held at this value for another 5 minutes. 1 μL of the sample was injected. The artemisinin standard was used for identification and quantification. Artemisinin is known to degrade during gas chromatography analysis [Christen, P., Veuthey, J.L. New trends in extraction, identification and quantification of artemisinin and its derivatives. Curr. Med. Chem., 2001, 8, 1827-1839], thus the indirect method of determination proposed by Sipahimalani et al [Sipahimalani, A.T., Fulzele, D.P., Heble, M.R. Rapid method for detection and determination of artemisinin by gas chromatography. J. Chromatogr., 1991, 538, 452-455] was used for this quantification assay.

The enriched fraction of the Artemisia annua extract obtained and purified from the process object of the present invention has an artemisinin content greater than 34%

Pharmaceutical composition comprising enriched fraction of Artemisia annua extract obtained from the process object of the present invention for the treatment of malaria Pharmaceutical composition

The pharmaceutical composition object of the present invention comprises: (i) enriched fraction of the Artemisia annua extract prepared from the process object of this invention; and (ii) a physiologically acceptable vehicle; all amounts being based on the total weight of the mixture.

The main examples of dosage forms of products that can be prepared from the pharmaceutical composition object of this invention are: a) injectable formulas; b) tablets; and c) suspensions;

As for the physiologically acceptable vehicle, it consists of a usual pharmaceutical base according to the intended application for the composition to be prepared. This vehicle consists of physiologically inert compounds and usual adjuvants.

Listed below are some examples - in a non-restrictive, but only demonstrative way - of adjuvants and inert constituents compatible with the properties of the composition described herein and which, in addition, can be used in the present pharmaceutical composition intended for the treatment of malaria:- Water: Water is the basis of several preferred embodiments of the pharmaceutical composition of the present invention, acting as the vehicle for the other components (including artemisinin, the main component of the enriched fraction of the extract). The compositions of the present invention preferably comprise sterile water in a suitable percentage (q.s.p.) to achieve 100% of the formula based on the total weight of the present composition. Of course, other physiologically acceptable carriers can be used in the present invention.- Antioxidant agents; -Preserving agents:- Gums and polysaccharides:- Disintegrating agents:

Having described an example of preferred embodiment, it should be understood that the scope of the present invention encompasses other possible variations, being limited solely by the content of the appended claims, including possible equivalents therein.

Claims (17)

1. Artemisinin extraction and purification process characterized by using supercritical carbon dioxide from solid mass of Artemisia annua which comprises: (i) extraction - contact of the plant material with the supercritical fluid of CO2 pressurized between 60 and 400 bar, preferably 100 bar, at a temperature of 30°C for a period of 1 and 60 minutes, preferably 10 minutes, at a ratio of 10 to 500 kg preferably 96.22 kg of CO2 to 1 kg of particulate solid mass and dissolution of the particulate solid mass by CO2 supercritical in an extractor (E1) obtaining CO2 and dissolved vegetable drug; (ii) adsorption - contact between CO2 and dissolved vegetable drug obtained in (i) and retention in the fixed polar phase in a fractionating column (F1) that follows gradient (% ethanol ) of 0, 1, 3, 5 and 10% (m/m) and retention of the vegetable drug; (iii) elution consisting of a contact between a mixture of CO2 and co-solvent with a fixed polar phase in the fractionating column (F1);( iv) the extractor (E1) and the fractionating column (F1) packed with polar physical phase in silica or alumina arranged in line in the same circuit. (v) obtaining artemisinin content greater than 34.9% by mass in the enriched fraction of the extract of hydrophilic components. 2. Process according to claim 1, characterized in that before the first step the extractor (E1) is fed with solid mass of particulate Artemisia annua and the fractionating column (F1) is packed with a fixed polar phase. 3. Process according to claim 1, characterized in that the first extraction step occurs simultaneously with the second purification step. 4. Process according to claim 1, characterized in that in the second purification step hydrophilic components present in the dissolved plant extract are retained in the fixed polar phase in the fractionating column (F1). 5. Process according to claim 4, characterized in that the CO2 and extract containing hydrophobic components present in the plant extract are directed to a fractionator (F1). 6. Process according to claims 1 and 5, characterized in that after the second adsorption step and before the third elution step, a mixture between supercritical and co-solvent CO2 occurs in a mixer (M1) that feeds said fractionator . 7. Process according to claim 6, characterized in that the co-solvent is selected from the group of polar solvents. 8. Process according to claim 7, characterized in that the co-solvent consists of ethanol. 9. Process according to claims 1 to 8 characterized in that the separator (S1) separates the CO2 from the extract containing a first fraction of Artemisia annua extract. 10. Process according to claim 9, characterized in that the separated, condensed CO2 is later directed to the storage tank and the extract is collected in a first collector (C1). 11. Process according to claims 5, 9 and 10, characterized in that in the third elution step the mixture of CO2 and co-solvent solubilizes the hydrophilic components of the dissolved plant extract adsorbed on the fixed polar phase in the fractionating column (F1) . 12. Process according to claim 10, characterized in that the mixture between CO2, co-solvent and hydrophilic components is directed to a separator (S1). 13. Process according to claim 12, characterized in that in the separator (S1) there is a separation between CO2 and co-solvent solution and hydrophilic components. 14. Process according to claim 12, characterized in that the separated CO2 is condensed and the solution of co-solvent and hydrophilic components is collected in a second collector (C2). 15. Process according to claim 13, characterized in that after the third elution step an inert pressurized gas is inserted into the fractionating column (F1) removing residues of hydrophilic components adsorbed to the polar fixed phase. 16. Process according to claim 14, characterized in that the residues of hydrophilic components are directed to a second collector (C2). 17. Process according to claims 13, 15 and 16, characterized in that the solution of co-solvent and hydrophilic components is subjected to evaporation separating the co-solvent and obtaining a fraction of the extract with hydrophilic components.

Images