Patent Application
20070259434
The present invention relates to an analytic method; more particularly, relates to easily and quickly obtaining an analysis on the radiochemical purity (RCP) of a sample.
Usually, a method used to obtain an analysis of RCP is selected from the following methods: one is an analysis method by using a Sep-Pac cartridge, and the other is an analysis method by using a High Pressure Liquid Chromatography (HPLC) system.
Regarding the analytic method by using a Sep-Pac cartridge, Sep-Pac cartridges (Waters, Milford, Mass., USA) are at first washed with methanol and water for injection; a plastic piston syringe having 1 milliliter (ml) capacity is used to aspirate 0.1 ml of a reconstruction sample of In-111-Pentetreotide to be injected into a Sep-Pac cartridge with 5 mL of water for injection added into the same cartridge while a first glass vial is used to collect the first fluid overflowed. Then, another piston syringe aspirates 5 mL of methanol is followed to flow through the same cartridge using the same way mentioned just now while a second glass vial is used to collect the second fluid overflowed. In the end, the other piston syringe aspirates 10 ml of air to be separately injected into the cartridges while a third glass vial is used to collect the third fluid overflowed; and then a radioactivity measurement (Capintac CRC-15 R ) i s used to measure radio-activities of the first, the second and the third glass vial to obtain the results A, B, C, respectively. So that the RCP for the sample of In-111-Pentetreotide is obtained according to the following formula:
[B/(A+B+C)]×100%.
Regarding the analysis method by using the HPLC system, a sodium acetate solution (solution A) and a methanol (solution B) are prepared. The solution A is obtained through the following steps: obtaining 6.8 g of sodium acetate accurately weighted; solving the sodium acetate into 500 mL of water for injection; adjusting the pH value of the solution to 5.5 by adding glacial acetic acid; and diluting the solution with water to 1000 ml amount. Then, a stainless steel tube filled with 10-μm C18 (VERCOPACK, 4.0 mm×30 cm) is used as a separation column. An irrigation solution is set to function in a gradient way, where ‘60% of solution A together with 40% of solution B’ is linearly changed to ‘20% of solution A together with 80% of solution B’ under a flow rate of 1 mL/min. A change monitor over radioactivity is done with a radio-detector to be shown by a diagram drawn. In the end, the RCP of In-111-Pentetreotide is obtained by an area integration of the diagram.
Although the above prior arts both can analyze the RCP of In-111-Pentetreotide, the equipments and the procedure used are complex with long processing time. Hence, the prior arts do not fulfill users' requests on actual use.
The present invention is to easily and quickly obtain an analysis on an RCP of a sample.
To achieve the above purpose, the present invention is a rapid method for determining an RCP of In-111-Pentetreotide, where an analysis of an RCP is obtained by using a technology of Thin-Layer Chromatography; the rapid method comprises steps of labeling developing spots, dropping a sample, developing the sample, heating and drying on the hotplate and obtaining the chromatogram for an analysis. At first, an Instant Thin-Layer Chromatography-Silica Gel (ITLC-SG) is obtained to be labeled with a beginning spot and an ending spot upon; then a sample of a reconstruction of the radioactive material is dropped at the beginning spot of the ITLC-SG. Later, the ITLC-SG is deposed in a developing tank to develop the sample and the developing tank has a buffer solution at bottom of the developing tank; after a liquid surface of the sample is developed to arrive at the ending spot of the ITLC-SG, the ITLC-SG is taken out to be dried by heating on the hot plate. Finally, after the ITLC-SG is dried by heating, the ITLC-SG is taken out to be analyzed by a radio-thin-layer chromatography scanner through an integration chromatography. Accordingly, a novel rapid method for determining an RCP of In-111-Pentetreotide is obtained.
The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which
The following description of the preferred embodiment is provided to understand the features and the structures of the present invention.
Please refer to
Please refer to
(A) Labeling developing spots: At first, a plate of an Instant Thin-Layer Chromatography-Silica Gel (ITLC-SG) [11] is obtained to be labeled with a beginning spot [12] at 2 centimeters (cm) to a boarder of the ITLC-SG [11] and an ending spot [13] at 12 cm to the boarder of the ITLC-SG [11].
(B ) Dropping a sample: Then, a sample [21] of a reconstruction of a radioactive material is dropped at the beginning spot [12] of the ITLC-SG
(C) Developing the sample: The ITLC-SG [11] dropped with the sample [21] is put in a developing tank [31] having a buffer solution of citrate buffer [32] at bottom to develop the sample; and the citrate buffer [32] of the developing tank [31] has a liquid level at 0.5 cm.
(D) Heating a plate: After a liquid surface of the sample [21] is developed to arrive at the ending spot [13] of the ITLC-SG [11], the ITLC-SG [11] is taken out to be dried by heating in a fume hood.
(E) Obtaining an analysis: Finally, after the ITLC-SG [11] is dried in step (D) of “Heating the ITLC-SG plate [4]”, the ITLC-SG [11] is taken out to be analyzed by a radio-thin-layer chromatography scanner (Bioscan-2000) through an integration chromatography so that an analysis of an RCP of the sample is obtained.
Please refer to
To sum up, the present invention is a rapid and convenient method for determining the RCP of In-111-Pentetreotide, where an analysis on an RCP of a sample is easily and quickly obtained.
The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.
