Method for the direct detection and/or quantification of at least one compound with a molecular weight of at least 200
The present invention relates to method for the direct detection and/or quantification of at least one compound with a molecular weight of at least 200, wherein the compound to be detected and/or quantified is a chemically complex molecule, wherein said chemically complex molecule is substituted with at least two groups R, wherein each R group means independently —OH, —OP(O)(OH)2 or —P(O)(OH)2, with the proviso that at least two R are independently selected from —P(O)(OH)2 and —OP(O)(OH)2, wherein the compound or compounds to be detected and/or quantified are within a biological matrix, wherein said biological matrix is a biological fluid, a biological tissue, stomach contents, intestine contents, stool sample or a culture cells, wherein the method comprises performing a chromatography and identifying the retention time and/or the intensity of the signal by means of a mass or radioactivity detector.
1. A method for analyzing a pharmaceutical composition comprising at least one phosphorus containing compound having a molecular weight of at least 200 daltons, wherein the amount of the at least one phosphorus containing compound in the pharmaceutical compostions is above 70% by weight,
wherein the method comprises quantifying the phosphorus containing compound together with its impurities, wherein
the at least one phosphorus containing compound is selected from:
(a) a bisphosphonate or polyphosphonate;
(b) a hexametaphosphate;
(c) a C3-C7 cycloalkyl substituted compound with at least two —R group wherein each —R group is —OH, —OP(O)(OH) 2 or —P(O)(OH) 2 , and wherein at least two —R groups are independently selected from —P(O)(OH) 2 and —OP(O)(OH) 2 and said C3-C7 cycloalkyl is cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl;
(d) ions or salts thereof; or,
(e) a combination thereof; and,
wherein said method comprises:
1) preparing at least one standard sample of a phosphorus containing compound to be analyzed;
2) preparing a test sample of the composition containing the at least one phosphorus containing compound, wherein the process to prepare said sample comprises at least partially or totally dissolving said composition to form a solution or a slurry containing the compound, without any sample pretreatment apart from diluting the test sample:
3) introducing the at least one standard sample together or sequentially with the test sample into a stream of a solvent system, wherein the solvent system is a polar solvent comprising potassium hydroxide (KOH) or a solvent mixture comprising at least one polar solvent comprising potassium hydroxide (KOH); and passing the samples through a single anion-exchange chromatography column containing particles of a polystyrene cross-linked with divinylbenzene polymer resin, wherein the column is essentially filled of the cross-linked polymer particles in a stationary phase while maintaining the pressure of the system in the anion-exchange chromatography column between 5 and 1500 atm; and,
4) identifying the retention time and/or quantifying the intensity of the signal of the at least one phosphorus containing compound when the samples are eluted from the anion-exchange chromatography column.
2. The method according to claim 1 , wherein identifying the retention time and/or quantifying the intensity of the signal of the at least one phosphorus containing compound is conducted by means of a mass spectrometry detector.
3. The method according to claim 2 , wherein the mass spectrometry detector is a tandem mass spectrometer, a triple quadrupole spectrometer, or a single quadrupole spectrometer.
4. The method according to claim 2 , wherein the mass spectrometry detector operates under selected ion monitoring (SIM) mode, multiple reaction monitoring (MRM) mode, selected reaction monitoring (SRM) mode, SCAN (positive/negative), or a combination thereof.
5. The method according to claim 1 , wherein the method further comprises quantifying the amount of the at least one phosphorus containing compound in the composition.
6. The method according to claim 1 , wherein the method further comprises quantifying the purity of the at least one phosphorus containing compound in the composition.
7. The method according to claim 1 , wherein the method is used to detect and quantify any of the impurities in an impurities profile.
8. The method according to claim 1 , wherein the C3-C7 cycloalkyl substituted compound is an inositol polyphosphate comprising from 2 to 6 phosphate groups.
9. The method according to claim 8 , wherein the inositol polyphosphate is phytate.
10. The method according to claim 1 , wherein the pH of the solvent system is between 7 and 14.
11. The method according to claim 1 , wherein the standard sample is a reference standard, an external standard, an internal standard, or a standard addition.
12. The method of claim 1 , wherein identifying the retention time and/or quantifying the intensity of the signal of the at least one phosphorus containing compound is conducted by means of post column derivatization followed by UV detection.
13. A process for preparing a pharmaceutical composition comprising at least one phosphorus containing compound having a molecular weight of at least 200 daltons, wherein the process comprises quantifying the compound together with its impurities, wherein
the at least one phosphorus containing compound is selected from:
(a) a bisphosphonate or polyphosphonate;
(b) a hexametaphosphate;
(c) a C3-C7 cycloalkyl substituted compound with at least two —R groups wherein each —R group is —OH, —OP(O)(OH) 2 or —P(O)(OH) 2 , and wherein at least two —R groups are independently selected from —P(O)(OH) 2 and —OP(O)(OH) 2 and said C3-C7 cycloalkyl is cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl;
(d) ions or salts thereof; or,
(e) a combination thereof; and,
wherein the process comprises measuring the percentage of purity of the at least one phosphorus containing compound in the pharmaceutical composition by a process comprising the method according to claim 1 , and including the batch of pharmaceutical composition only if the percentage of purity of the at least one phosphorus containing compound is above 70% by weight.