Considering that approximately a third of all drugs currently on the market is derived from natural products, curcumin attracted attention due to its anticancer, antioxidative, antiinflammatory and antimicrobial properties. Unfortunately, its low solubility and depending on that a poor bioavailability are limiting factors for its clinical application. It was shown that the administration of curcumin with piperin, the main component of black pepper, increased the bioavailability of curcumin. In addition, piperine increased the plasma concentration and delayed the elimination of drugs like phenytoin and rifampin, and has antiinflammatory and antifungal properties among others. Considering the literature has shown that for extracting curcumin and piperine, respectively, Soxhlet, microwave-assisted extraction, supercritical carbon dioxide extraction and concentional extraction with ethanol as solvent were used among others. According to the concentional extraction of curcumin with ethanol important parameter like the ethanol concentration was not investigated. In addition the maximum extraction time in this case was only 50 minutes, too short in our opinion. Due to these facts the optimum extraction parameters for the conventional extraction of curcumin from turmeric and of piperine from black pepper, respectively, were investigted in this study, with respect to extraction time of 7-21 hours, ethanol concentration of 10-90 % and drug to solvent ratio of 1:10-1:30. Response surface methodology was used as a tool to determine the optimum conditions for the extraction of curcumin and piperine, with help of an experimental design, central composite design. The ideal parameter for this conventional extraction of curcumin from turmeric and of piperine from black pepper, respectively, were an extraction time of 15 hours, an ethanol concentration of 70 % (v/v) and a drug to solvent ratio of 1:20.Considering that approximately a third of all drugs currently on the market is derived from natural products, curcumin attracted attention due to its anticancer, antioxidative, antiinflammatory and antimicrobial properties. Unfortunately, its low solubility and depending on that a poor bioavailability are limiting factors for its clinical application. It was shown that the administration of curcumin with piperin, the main component of black pepper, increased the bioavailability of curcumin. In addition, piperine increased the plasma concentration and delayed the elimination of drugs like phenytoin and rifampin, and has antiinflammatory and antifungal properties among others. Considering the literature has shown that for extracting curcumin and piperine, respectively, Soxhlet, microwave-assisted extraction, supercritical carbon dioxide extraction and concentional extraction with ethanol as solvent were used among others. According to the concentional extraction of curcumin with ethanol important parameter like the ethanol concentration was not investigated. In addition the maximum extraction time in this case was only 50 minutes, too short in our opinion. Due to these facts the optimum extraction parameters for the conventional extraction of curcumin from turmeric and of piperine from black pepper, respectively, were investigted in this study, with respect to extraction time of 7-21 hours, ethanol concentration of 10-90 % and drug to solvent ratio of 1:10-1:30. Response surface methodology was used as a tool to determine the optimum conditions for the extraction of curcumin and piperine, with help of an experimental design, central composite design. The ideal parameter for this conventional extraction of curcumin from turmeric and of piperine from black pepper, respectively, were an extraction time of 15 hours, an ethanol concentration of 70 % (v/v) and a drug to solvent ratio of 1:20
