Abstract: An object the invention is to provide a method of analyzing the activation ratio of terminals of a polyoxyalkylene derivative so that the ratio can be accurately measured at a high precision even when the polyoxyalkylene derivative has a high molecular weight. The activation ratio of terminal of a polyoxyalkylene derivative having a terminal active group capable of bonding with a biologically active substance having a molecular weight of 1000 to 100000 is analyzed. The active group is labeled using a labeling reagent having an ionic functional group. The polyoxyalkylene derivative is then analyzed by means of liquid chromatography using an ion-exchange column and an RI detector outputting a chromatogram. The activation ratio of terminal is obtained based on percentage of an area of a peak corresponding to the active group in the chromatogram.

Abstract: Polyethylene glycol for use in fields with application to a living body wherein the sum of the contents of ethylene glycol and diethylene glycol in the polyethylene glycol is less than or equal to that expressed in the following formula [I]: Sum ⁢   ⁢ of ⁢   ⁢ ethylene ⁢   ⁢ glycol ⁢   ⁢ and ⁢   ⁢ diethylene ⁢   ⁢ glycol ⁢   ⁢ contents ⁢  

Abstract: Polyethylene glycol for use in fields with application to a living body wherein the sum of the contents of ethylene glycol and diethylene glycol in the polyethylene glycol is less than or equal to that expressed in the following formula [I]: 1 Sum ⁢   ⁢ of ⁢   ⁢ ethylene ⁢   ⁢ glycol ⁢   ⁢ and ⁢   ⁢ diethylene ⁢   ⁢ glycol ⁢   ⁢ contents ⁢   ⁢ ( ppm ) = 150 × 2900 × 0.

Abstract: Polyethylene glycol for use in fields with application to a living body wherein the sum of the contents of ethylene glycol and diethylene glycol in the polyethylene glycol is less than or equal to that expressed in the following formula [I]: Sum ⁢   ⁢ of ⁢   ⁢ ethylene ⁢   ⁢ glycol ⁢   ⁢ and ⁢   ⁢ diethylene ⁢   ⁢ glycol ⁢   ⁢ contents ⁢  

Abstract: Polyethylene glycol for use in fields with application to a living body wherein the sum of the contents of ethylene glycol and diethylene glycol in the polyethylene glycol is less than or equal to that expressed in the following formula [I]: 1 Sum ⁢   ⁢ of ⁢   ⁢ ethylene ⁢   ⁢ glycol ⁢   ⁢ and ⁢   ⁢ diethylene ⁢   ⁢ glycol ⁢   ⁢ contents ⁢   ⁢ ( ppm ) = 150 × 2900 × 0.

Abstract: An oxirane derivative and process for preparation of the same, having a high purity characterized in terms of gel permeation chromatography and thin layer chromatography. The oxirane derivative is useful as a starting material for medical purposes, and mainly drug delivery systems.

Abstract: The present invention provides an high purity and high molecular oxirane derivative useful as a starting material for medical purposes, mainly drug delivery system, and a process for the preparation thereof.

Abstract: A process for producing a polyoxyalkylene derivative substituted with succinimidyl group which comprises reacting a polyoxyalkylene compound having carboxyl group at ends with N-hydroxysuccinimide in an inert solvent in the presence of dicyclohexylcarbodiimide; dissolving an obtained reaction product into chloroform, an amount by weight of chloroform being 0.5 to 10 times as much as an amount by weight of the polyoxyalkylene compound having carboxyl group at ends; and crystallizing the polyoxyalkylene derivative substituted with succinimidyl group by adding an aliphatic hydrocarbon having 5 to 8 carbon atoms to a resultant solution, an amount by weight of the aliphatic hydrocarbon being 2 to 10 times as much as an amount by weight of chloroform. Materials can be handled with safety, and a highly pure polyoxyalkylene derivative substituted with succinimidyl group which does not cause turbidity in an aqueous solution and has an excellent quality as a material for drugs can be produced.

Abstract: A process for producing a polyoxyalkylene derivative substituted with succinimidyl group which comprises reacting a polyoxyalkylene compound having carboxyl group at ends with N-hydroxysuccinimide in an inert solvent in the presence of dicyclohexylcarbodiimide; filtering an obtained reaction product; and crystallizing the polyoxyalkylene derivative substituted with succinimidyl group by adding isopropyl alcohol to a filtrate obtained by the filtration, an amount by weight of isopropyl alcohol being 1 to 100 times as much as an amount by weight of the polyoxyalkylene compound having carboxyl group at ends.Materials can be handled with safety in the process of the present invention, and a highly pure polyoxyalkylene derivative substituted with succinimidyl group which does not cause turbidity in an aqueous solution and has an excellent quality as a material for drugs can be produced.

Abstract: A reactive vesicle comprising, as a vesicle-forming component, a reactive phospholipid derivative represented by the following general formula (1) and a functional substance-fixed vesicle prepared by reacting the reactive vesicle with a functional substance: ##STR1## in which R.sup.1 C(.dbd.O) and R.sup.2 C(.dbd.O) each represent an aliphatic acyl group, R.sup.3 denotes hydrogen atom or methyl group, OA represents an oxyalkylene group of 2-4 carbon atoms, n indicates the average number of moles of added oxyalkylene group and is 1-1,000, p is 0 or 1, X represents ##STR2## with q and r each being an integer of 0 to 4 or 1 to 4, respectively, and M denotes hydrogen atom or an alkli metal atom.

Abstract: A novel and useful phospholipid derivative to be used for a reactive vesicle-forming agent, which is represented by the following general formula (1): ##STR1## in which R.sup.1 C(.dbd.O) and R.sup.2 C(.dbd.O) represent each an aliphatic acyl group, R.sup.3 denotes hydrogen atom or methyl group, OA represents an oxyalkylene group of 2-4 carbon atoms, n indicates the average addition mole number of added oxyalkylene group and is 1-1,000, p is 0 or 1, X represents ##STR2## with q and r being each an integer of 0 to 4 or 1 to 4, respectively, and M denotes hydrogen atom or an alkali metal atom.