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The Preparation of Pyrogen-Free Inulin Solution
PREPARATION OF
PYROGEN-FREE INULIN SOLUTION by DON E. FRANCKE and VINCENT L. REES UNIVERSITY HOSPITAL, UNIVERSITY OF MICHIGAN
R
ICHARDS in 1934 introduced inulin (a starchlike polymer of fructose) as an inert compound removed from the human body exclusively through renal glomerular filtration. It promptly became of interest to the physiologists because with it they had a means of measuring one of the specific physiological activities occurring in the kidney, namely, glomerular filtration. More recently, it has been utilized clinically to specifically determine the renal changes occurring in various pathological states. By means of inulin clearance studies, an accurate knowledge of glomerular activity can be obtained. With the advent of the present war, filters essential for the preparation of pyrogen-free solutions of inulin were no longer available and so both experimental and commercial preparations of pyrogen-free inulin were no longer available. Attempts were then made to devise a method of purifying inulin with materials that were available. After several attempts, we were successful in preparing a 10 percent solution of chemically pure inulin that, when administered intravenously, caused no untoward reactions and proved a satisfactory agent for studying renal filtration. It has been shown that solutions may be rendered pyrogen free by filtration 1 ' 2 through a double Seitz No.3 filter pad or by shaking 3 the solution for a few minutes with powdered char-' coal and then removing the charcoal by filtration. In each of these methods the pyrogens are adsorbed frbm the solution. Both of these methods were tried in an attempt to prepare a pyrogen-free inulin solution. However, since with this particular preparation, neither method was successful, it was decided to try a combination of the two methods. By using the combined method we were able to prepare solutions of pyrogen-free inulin. After preparation all lots were tested for pyrogens, first on dogs, and then if negative, on man.
A sterile nonpyrogenic solution of chemically pure inulin suitable for intravenous use may be prepared as follows: Inulin, c. P ..••.•........ . ....... Sodium chloride, c. P •••. • • • •••• . • Water for injection, U. S. P .. . ... .
10.0% 0.9% 89.1%
Heat the recently distilled water to 80 0 C. dissolve the salt and then the inulin in the water. Transfer the resulting solution to a bottle of suitable size, add 0.1 percent powdered charcoal, * and agitate in a shaking machine for twenty minutes. To remove most of the charcoal, filter by suction through a Buchner funnel fitted with a medium filter paper to which a Kleenex tissue has been added; this latter device greatly facili· tates filtration. Immediately after the coarse filtration the solution is passed by means of combined pressure and suction through a Seitz· Uhlenhut-Monteufel filter which has been pre· viously fitted and sterilized with double filter pads. t The resulting solution is then ready to be filled into ampuls and autoc1aved at 250 0 F. for fifteen minutes. After the solution has been autoclaved it is tested for pyrogens.
CONCLUSION Sterile non pyrogenic solutions of chemically pure inulin suitable for intravenous injection may be prepared by treating a solution of chemically pure inulin in physiological saline with charcoal and then passing the solution through a Seitz filter fitted with double filter pads. REFERENCES
* HNucbar;" Nuchar Laboratories, 230 Park Avenue, New York, N. Y. t Filter Pad, Serum No. I, Republic Filters, Inc., Pater·
501: NC~' Tui;
McCloskey, K. L.; Schrift, Milton; and Yates, A. L., J . Am. M.d. Assoc., 109 (1937),250. d 2 Co Tui' Schrift, Milton; McCloskey, K. L.; an Yates, A. L., Soc. Exp. Bioi. M.d., 36 (1937), 227. 3. Lees, J. C., and Levvy, G. A., Brit. M_d. J., 1 (1940), 430.
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PYROGEN-FREE INULIN SOLUTION by DON E. FRANCKE and VINCENT L. REES UNIVERSITY HOSPITAL, UNIVERSITY OF MICHIGAN
R
ICHARDS in 1934 introduced inulin (a starchlike polymer of fructose) as an inert compound removed from the human body exclusively through renal glomerular filtration. It promptly became of interest to the physiologists because with it they had a means of measuring one of the specific physiological activities occurring in the kidney, namely, glomerular filtration. More recently, it has been utilized clinically to specifically determine the renal changes occurring in various pathological states. By means of inulin clearance studies, an accurate knowledge of glomerular activity can be obtained. With the advent of the present war, filters essential for the preparation of pyrogen-free solutions of inulin were no longer available and so both experimental and commercial preparations of pyrogen-free inulin were no longer available. Attempts were then made to devise a method of purifying inulin with materials that were available. After several attempts, we were successful in preparing a 10 percent solution of chemically pure inulin that, when administered intravenously, caused no untoward reactions and proved a satisfactory agent for studying renal filtration. It has been shown that solutions may be rendered pyrogen free by filtration 1 ' 2 through a double Seitz No.3 filter pad or by shaking 3 the solution for a few minutes with powdered char-' coal and then removing the charcoal by filtration. In each of these methods the pyrogens are adsorbed frbm the solution. Both of these methods were tried in an attempt to prepare a pyrogen-free inulin solution. However, since with this particular preparation, neither method was successful, it was decided to try a combination of the two methods. By using the combined method we were able to prepare solutions of pyrogen-free inulin. After preparation all lots were tested for pyrogens, first on dogs, and then if negative, on man.
A sterile nonpyrogenic solution of chemically pure inulin suitable for intravenous use may be prepared as follows: Inulin, c. P ..••.•........ . ....... Sodium chloride, c. P •••. • • • •••• . • Water for injection, U. S. P .. . ... .
10.0% 0.9% 89.1%
Heat the recently distilled water to 80 0 C. dissolve the salt and then the inulin in the water. Transfer the resulting solution to a bottle of suitable size, add 0.1 percent powdered charcoal, * and agitate in a shaking machine for twenty minutes. To remove most of the charcoal, filter by suction through a Buchner funnel fitted with a medium filter paper to which a Kleenex tissue has been added; this latter device greatly facili· tates filtration. Immediately after the coarse filtration the solution is passed by means of combined pressure and suction through a Seitz· Uhlenhut-Monteufel filter which has been pre· viously fitted and sterilized with double filter pads. t The resulting solution is then ready to be filled into ampuls and autoc1aved at 250 0 F. for fifteen minutes. After the solution has been autoclaved it is tested for pyrogens.
CONCLUSION Sterile non pyrogenic solutions of chemically pure inulin suitable for intravenous injection may be prepared by treating a solution of chemically pure inulin in physiological saline with charcoal and then passing the solution through a Seitz filter fitted with double filter pads. REFERENCES
* HNucbar;" Nuchar Laboratories, 230 Park Avenue, New York, N. Y. t Filter Pad, Serum No. I, Republic Filters, Inc., Pater·
501: NC~' Tui;
McCloskey, K. L.; Schrift, Milton; and Yates, A. L., J . Am. M.d. Assoc., 109 (1937),250. d 2 Co Tui' Schrift, Milton; McCloskey, K. L.; an Yates, A. L., Soc. Exp. Bioi. M.d., 36 (1937), 227. 3. Lees, J. C., and Levvy, G. A., Brit. M_d. J., 1 (1940), 430.
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