JPH04256434A - Pyrogen adsorbent - Google Patents

Abstract

PURPOSE:To remove a pyrogen, that is, a substance which causes pyrexia by adsorption when allowed to enter a living body by injection, artificial dialysis or other method. CONSTITUTION:This pyrogen absorbent is porous silica gel having amino and hydrophobic groups obtd. by allowing porous silica gel to react with a silane coupling agent having amino and hydrophobic groups.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorbent effective for removing a pyrogen, a substance that induces heat generation when administered or eluted into a living body by injection, artificial dialysis, etc. More specifically, the present invention relates to an adsorption/removal agent for pyrogens contained in injection solutions, infusions, dialysates, and the like.

0002

BACKGROUND OF THE INVENTION It has been found that lipopolysaccharide (LPS), which is derived from the cell walls of Gram-negative bacteria such as Escherichia coli, is currently a problematic pyrogen. Various studies have been conducted regarding the removal of pyrogens, and attempts have been made to remove them using activated carbon, ion exchange resins, and various separation membranes, but they have not yet reached the level of practical use. That is, these adsorbents have low selectivity for pyrogen, and a satisfactory amount of adsorption and removal cannot be obtained. Furthermore, there is also the problem of impurity elution during the adsorbent synthesis process, so it is currently impossible to actually use it.

0003

Problems to be Solved by the Invention In view of the above-mentioned drawbacks of the prior art, the present invention provides high pyrogen selectivity,
The object of the present invention is to obtain a pyrogen adsorbent that has a sufficient amount of adsorption and removal and does not have the problem of impurity elution during the synthesis process.

0004

[Means for Solving the Problem] The present inventors have conventionally discovered that the phosphoric acid group of LPS interacts with the amino group, and that among the amino groups, the primary amino group type has the weakest interaction with anionic substances. , the selectivity for LPS is high, and when the amino group is bonded to the end of the hydrophobic group, LPS
The phosphoric acid groups and hydrophobic groups of silica gel interact with each other, resulting in high selectivity and adsorption ability.Furthermore, since silica gel involves a sintering operation during its manufacturing process, it does not contain bioreactive foreign substances and is suitable for processing such as infusions. Based on this knowledge, the present invention was completed.

That is, an object of the present invention is to provide a pyrogen adsorbent comprising silica gel bonded with a functional group having an amino group and a hydrophobic group, particularly a pyrogen adsorbent in which the silica gel is porous.

The silica gel used in the present invention is obtained by a normal sintering method and may be in either granular or crushed form. Furthermore, silica gel having a porous structure is particularly preferable because it has a large surface area involved in adsorption.

[0007] In the present invention, the functional group having an amino group and a hydrophobic group refers to a functional group containing one or more primary, secondary, tertiary or quaternary amino groups, and containing carbonized alkyl groups, aryl groups, phenyl groups, etc. Monoaminoalkyl groups such as aminoethyl, aminopropyl, aminobutyl, and aminohexyl groups; diaminoalkyl groups such as diaminoethyl, diaminopropyl, diaminobutyl, and diaminohexyl groups; Groups, etc. These amino groups may be bonded to any part of the hydrophobic group, but preferably at least one of these amino groups is bonded to the terminal. Further, the hydrophobic group may contain an ether bond, an amide bond, an ester bond, etc. The amino group contained in the silica gel is preferably 0.01 meq/g or more, more preferably 0.1 meq/g.
It is equal to or higher than eq/g.

[0008] A method for introducing these functional groups having an amino group and a hydrophobic group into silica gel usually uses a silane coupling reaction. That is, a silane coupling agent having the above amino group and a hydrophobic group, such as diethylaminopropyltriethoxysilane, aminobenzyltriethoxysilane, diethylaminoethyl phenyltriethoxysilane, etc., is added to silica gel dispersed in a dehydrated solvent. It reacts quickly at room temperature. After the reaction is completed, the silica gel is separated by filtration, centrifugation, etc.
Wash the gel with distilled water and a suitable organic solvent. The adsorbent thus prepared is used for adsorption after being sufficiently washed with a buffer solution, saline, etc.

[0009]

[Operation] According to the present invention, a technology for adsorbing pyrogens contained in injection solutions, dialysates, infusions, culture chemicals, etc. has been established. Although the mechanism is not clear, it is thought that LPS is selectively adsorbed by the amino group of the adsorbent and the hydrophobic group bonded thereto.

0010

Effects of the Invention The pyrogen adsorbent of the present invention (1) has high selectivity without adsorbing salts, amino acids, and useful proteins other than pyrogens; (2) has a large adsorption amount and adsorption rate of pyrogens ( 3) The adsorbent has excellent effects such as biocompatibility.

[0011]

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. The quantitative measurement of pyrogens was conducted by Seikagaku Kogyo Co., Ltd. (
A limulus color development test was conducted using an endotoxin quantitative reagent kit manufactured by Co., Ltd.). Production Example 1 Fully porous spherical silica gel for column chromatography (
15-40μm) well dried and dehydrated THF1
Dispersed in 00cc. To this was added 1.4 g of diethylaminopropyltriethoxysilane and the mixture was reacted for 2 hours under a nitrogen atmosphere, followed by filtration and thorough washing with distilled water and ethanol. The obtained gel was sufficiently dried and the amino group content was measured by titration and found to be 0.84 meq/g.

Production Example 2 In Production Example 1, 1 g of aminobenzyltriethoxysilane was used instead of diethylaminopropyltriethoxysilane.
It was synthesized in the same manner using The amino group content of the obtained gel was 0.54 meq/g.

Production Example 3 Synthesis was carried out in the same manner as in Production Example 1 except that 2 g of diethylaminohexyltriethoxysilane was used in place of diethylaminopropyltriethoxysilane. The amino group content of the obtained gel was 1.04 meq/g.

Example 1 1 g of each of the adsorbents obtained in Production Examples 1, 2, and 3 was
Stainless steel column (inner diameter 4.5mm, length 150mm)
Filled with 100ml of 30mmol phosphate buffer, 1mol
After passing 150 ml of saline at a rate of 0.5 ml/min, the salt is completely washed away with pyrogen-free distilled water, and then endotoxin derived from Escherichia coli (LPS control manufactured by Seikagaku Kogyo Co., Ltd.) is removed.
055-B5) 25ml of distilled water adjusted to 1ng/ml
was passed through the column at a flow rate of 0.5 ml/min, and the endotoxin contained in the distilled water collected from the column outlet was quantified.

Example 2 L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-threonine, L
- Distilled water containing 0.1 g/1 each of valine and L-tryptophan was added to Escherichia coli-derived endotoxin (LPS control manufactured by Seikagaku Corporation) E. coli 0
100 ml of solution adjusted to 1 ng/ml with 55-B5)
1 g of each of the adsorbents obtained in Production Examples 1 and 2 was dispersed therein and allowed to adsorb at room temperature for 8 hours while stirring.

The endotoxin concentration and amino acid concentration of the adsorbed supernatant were measured, and the endotoxin adsorption rate and amino acid recovery rate were calculated. For amino acid analysis, an amino acid analyzer manufactured by JASCO Corporation was used. Adsorbent production example 1 Adsorbent production example 2 Adsorbent production example 3 Endotoxin adsorption rate 99.5%
99.3% 99.7% Amino acid recovery L-isoleucine 99.1%
99.2% 98.9%L-leucine 97.5%
95.5% 96.8%L-lysine 98.8%
94.8% 93.7%L-Methionine 99.5%
96.8% 94.8%L-phenylalanine 96.9% 93.6
% 96.5% L-threonine
98.2% 98.8%
94.4% L-valine
99.0% 97.5%
97.1% L-tryptophan
95.7% 96.7%
94.7%

Example 3 The endotoxin concentration contained in the artificial kidney dialysis fluid was 1
．． It was 4ng/ml. 500 cc of this dialysate was passed through a stainless steel column filled with 2 g of the adsorbent prepared in Synthesis Examples 1, 2, and 3 at a flow rate of 1 ml/min, and the endotoxin concentration in the dialysate flowing out from the column was measured. Furthermore, no changes were observed in the concentrations of various ions and sugars in the adsorbed dialysate.

Claims (2)

[Claims] 1. A pyrogen adsorbent made of silica gel having an amino group and a hydrophobic group. Claim 2: Claim 1, wherein the silica gel is a porous material.
Pyrogen adsorbent as described.