CN1202067C - Medicinal grade ferrum citricum iron-59 citrate and its preparation method - Google Patents

Abstract

The present invention provides medicinal grade ferric citrate. The mole percentage ratio of a citric acid radical contained in ferric citrate to Fe is from 99 to 101%. The medicinal grade ferric citrate provided by the present invention is prepared by refining normal ferric citrate by polar organic solvent. The polar organic solvent is selected from solvents in which the ferric citrate is not dissolved basically. The present invention also provides a medical composition which takes the ferric citrate as an active component and can be used for treating hyperphosphatemia caused by renal failure.

Description

The preparation method of pharmaceutical grade ferric citrate

Technical field

The present invention relates to pharmacy field, relate to pharmaceutical grade ferric citrate preparation and preparation thereof and process for purification.The pharmaceutical composition that to the invention still further relates to this pharmaceutical grade ferric citrate be effective constituent, this medical compounds can be treated because the hyperphosphatemia that renal failure causes.

Technical background

Ferric citrate has been used for many years as a kind of Chemicals, claims ironic citrate again, is the uncertain compound of a kind of structure.The ferric citrate of food additive grade and chemical reagent-grade had just had the record of suitability for industrialized production in the past as far back as nineteen fifties.

The method of the synthetic ferric citrate of document record is to be raw material with citric acid and ironic hydroxide, and citric acid is added in the ironic hydroxide liquid, to be lower than 60 ℃ temperature heating, is evaporated to pulpous state, coats on the sheet glass, and cryodrying is peeled off promptly to forming small thin slices.But continue to use this method of getting off for many years very big randomness should be arranged, only require in the finished product based on ferric citrate, each conditional parameter for preparation process does not have very clear and definite requirement, so it is rough ferric citrate that the ferric citrate product of this routine can only be called, be the thin flakey of puce, quality is loose, wherein contains more residual Citric Acid, can have influence on the quality and the action and efficacy of ferric citrate in use, also cause the waste of big content of starting materials (Citric Acid) simultaneously.This method does not have any progress for many years always yet.

For the ferric citrate of above-mentioned routine being made with extra care or being purified, the big water gaging flushing of Ceng Youyong is being used to remove the polymictic method of trying one's best in the industry, but ferric citrate still has certain solubleness in water, big water gaging dashes except that meeting causes the loss of ferric citrate, also can increase loss because of it is partly dissolved, add mass consumption water, cause whole process cost height and having little effect of playing.As the ferric citrate of food grade and SILVER REAGENT, all be that citric acid radical content wherein is all more than 102% after measured with making with extra care that this method or similar approach are carried out at present.

Because ferric citrate all is to be applied in chemical field for many years, wherein the content of citric acid radical does not put forward with regard to being used as an index strictness yet.Proposed ferric citrate in the United States Patent (USP) 5753706 first and can reduce human body to absorbing in the phosphatic intestines, thereby can be used for treating because the hyperphosphatemia that renal failure causes.The present invention is incorporated by reference in its entirety.The applicant has been found that too high citric acid radical content (being higher than 102%) can cause renal failure patient's metabolism disorder.So a very crucial problem is that the ferric citrate product that can be used for pharmacy field must be arranged in the enforcement of this United States Patent (USP).

In a word,, restricted the suitability for industrialized production of pharmaceutical grade ferric citrate preparation, also influenced the application of ferric citrate in field of medicaments owing to lack a kind of effective process for purification.

Summary of the invention

The present invention just is being based on the production needs of pharmaceutical grade ferric citrate, has proposed a kind of method that can effectively make with extra care ferric citrate, but and then provides the ferric citrate preparation of fulfilling medicinal demand.

A kind of synthetic method for preparing ferric citrate of the also corresponding proposition of the present invention by specializing of operational condition, has shortened the reaction times when improving yield, make the preparation process of ferric citrate adapt to industrialized operational requirement more.

Based on the pharmaceutical use of ferric citrate in the hyperphosphatemia that treatment causes owing to renal failure, the present invention also provides corresponding pharmaceutical compositions and pharmaceutical dosage form.

Ferric citrate generally becomes sorrel transparent sheet and brown ceramic powder, and it is acid that its aqueous solution becomes, and is not soluble in cold water, but then can slowly dissolve when the water water temperature raises, and permanent the stirring more increases dissolving.On the other hand, ferric citrate is insoluble to the polar organic solvent of some short carbon chains such as ethanol.Applicant of the present invention is based on the character of ferric citrate, a kind of process for purification that is different from conventional process has been proposed, this treating process comprises uses polar organic solvent that the ferric citrate that has synthesized is soaked removing residual Citric Acid and impurity, and described polar organic solvent is selected from the insoluble basically solvent of ferric citrate.

Lot of experiment results proves, handles ferric citrate with organic solvent, is a kind of effective process for purification, and the citric acid radical that can make in the product to be contained and the molar percentage of iron become the ferric citrate of pharmaceutical grade at 99-101%.

Obviously, described polar organic solvent should be to be selected from the insoluble basically solvent of ferric citrate.The present invention preferably uses alcohols, ketone, ethers and the ester class equal solvent of 2-6 carbon, and it is ethanol, propyl alcohol, ethylene glycol, acetone, ethyl acetate, ether or methyl ethyl ether etc. that You Xuanke uses the solvent example.In refining, per 1 kilogram of ferric citrate can soak with the solvent about the 7000-8000 milliliter, and the ferric citrate yield after making with extra care can reach more than 99%.

The preferred treating process according to the present invention, be with 95% ethanol under room temperature or the subambient temperature to ferric citrate extraction once more than, the collecting precipitation thing promptly gets the pharmaceutical grade ferric citrate that meets the demands.

Described extraction can be immersed in ferric citrate in the solvent 1-2 hour, makes remaining Citric Acid dissolving, filters out solid then, can adopt vacuum filtration, uses solvent elution once more for the particle that leaches, and the gained solid be even shinny puce particle.

The present invention has also attempted cooperating purification operations with the synthetic ferric citrate of more scientific and effective method when groping to obtain the process for purification of medicinal ferric citrate, makes whole process of preparation more scientific and reasonable, is more suitable for the popularization of suitability for industrialized production.The applicant has passed through a large amount of experiments and analysis, find, because ferric citrate is a kind of compound that has the undefined structure of crystal water, iron exists with the form of complexing, be generally trivalent, under the influence of light and heat, can be reduced into ferrous salt, make entire structure destroyed, thereby the synthetic of ferric citrate on the books all be at low temperature, is lower than specifically under 60 ℃ and carries out.The present inventor is in the discovery in the experiment of groping to speed of reaction under the differing temps and productive rate, and temperature is influential to the two, and especially high temperature more helps the raising of speed of reaction.When temperature of reaction at 70 ℃, speed of reaction and productive rate and 90 ℃ do not have very big difference down, and the reaction yield under 60 ℃ is about 88%, 70 ℃ down or the reaction yield when being higher than 70 ℃ then can reach 95%, the shortening in reaction times helps more preventing that product is influenced by light and heat and destroys.So it is the process of the synthetic ferric citrate of raw material that the present invention has further proposed with ironic hydroxide and Citric Acid, wherein, the equivalence ratio of Citric Acid and ironic hydroxide is greater than 1.0, and temperature of reaction 60-70 ℃, synthetic product is in oven dry below 60 ℃.

All be that the requirement Citric Acid is excessive usually in the building-up reactions, with the carrying out that helps to react, but the inventor finds, when the equivalence ratio of Citric Acid and ironic hydroxide greater than 1.05 the time, although initial reaction stage is to reacting helpful, but the viscosity of product is bigger, influences the formation of product short texture, makes the wash-out impurity in the treating process that difficulty take place.So, the preferable methods according to the present invention, when synthesizing ferric citrate, the equivalence ratio of ironic hydroxide and Citric Acid is 1: 1.0-1: 1.05, reaction times 48-72 hour.In the concrete operations, can decide temperature of reaction according to turnout, for example, about 70 ℃ of in a small amount synthetic may command to be adding fast response, and are in enormous quantities synthetic owing to stir and be difficult for, and can be reduced to 60 ℃ or a little more than 60 ℃, the proper extension reaction times.

According to another aspect of the present invention, also proposed a kind of treatment because the pharmaceutical composition of the hyperphosphatemia that renal failure causes, it comprises acceptable assistant agent on the above-mentioned pharmaceutical grade ferric citrate for the treatment of significant quantity and the pharmaceutics.

On zooperal basis, can tentatively determine the dosis tolerata of human body, and the ferric citrate that draws in the significant quantity of treatment described in the composition of the present invention in conjunction with drug efficacy study (comprising clinical single-dose tolerance test and successive administration tolerance test) is generally in single dose 500-3000 milligram.Preferably, the single dose of ferric citrate is the 1000-2500 milligram in the described pharmaceutical composition, more preferably 2000 milligrams.

Pharmaceutical composition of the present invention can be a solution for example, and acceptable assistant agent comprises solvent, sanitas, correctives or seasonings on the described pharmaceutics; Syrup, acceptable assistant agent comprises sucrose, sanitas, correctives or seasonings on the described pharmaceutics; Gelifying agent, acceptable assistant agent comprises jelling agent, sanitas, correctives or seasonings on the described pharmaceutics; Capsule; Granule; Powder or tablet.

In the above-mentioned assistant agent, sanitas can be: Tegosept E, quaternary ammonium salt, Sodium Benzoate, Sorbic Acid etc.Correctives can comprise sweeting agent, essence, rectify slurry agent, effervescent etc.Jelling agent is glycerine or propylene glycol and derivatived cellulose, carbomer, alginates, tragcanth, gelatin, starch etc. for example.

When making capsule, granule, powder or tablet, the available auxiliary material is material conventional on the pharmaceutics, and the present invention does not have special requirement.

Enforcement of the present invention provides the pharmaceutical grade that can be used for pharmaceutical industry ferric citrate, and can help to make the especially preparation of specificationization of pharmaceutical grade ferric citrate of ferric citrate, thereby realizes suitability for industrialized production.Also preparation is used for the treatment of because the medicine of the hyperphosphatemia that renal failure causes provides the foundation as effective constituent in order to utilize ferric citrate simultaneously in the present invention.

Pharmaceutical research and result

The main pharmacodynamics experiment: oral ferric citrate absorbs and metabolic influence chronic kidney hypofunction rat model inorganic phosphorus.

Pharmacological room of Nat'l Pharmaceutical ﹠ Biological Products Control Institute has carried out the main pharmacodynamics viewing test of ferric citrate to the renal failure rat.The content of phosphorus in concentration by measuring phosphorus, creatinine, blood urea nitrogen in chronic kidney hypofunction rat model serum and the urine and the ight soil, observing oral ferric citrate, and then estimate its therapeutic action to hyperphosphatemia due to the renal failure to the influence of chronic kidney hypofunction rat phosphate absorption and excretory.

The rat of the Wistar of laboratory animal: 250g～300g; Positive control drug: lime carbonate, analytical pure; Instrument: Hitachi produces 7060 automatic biochemical analyzers, creatinine, blood urea nitrogen, determination of inorganic phosphorus test kit, microplate reader; Special feed: in basic mash feed, add the different pharmaceutical powder respectively, stir and make particle.Pseudo-operation group and feed that model group is eaten are phosphorous 0.739%, and lime carbonate feed that group is eaten phosphorous 0.722% contains lime carbonate 2.33%, and ferric citrate feed that high dose group is eaten is phosphorous 0.704%, contains ferric citrate 4.76%; Dosage feed that group is eaten is phosphorous 0.721% in the ferric citrate, contains ferric citrate 2.44%; Ferric citrate feed that low dose group is eaten is phosphorous 0.730%, contains ferric citrate 1.23%.

Experimental technique: rat is divided into 6 groups at random, is respectively: pseudo-operation group, model group, lime carbonate group, high dose group, middle dosage group and low dose group, 10 of pseudo-operation groups, all the other every group 14.Except puppet operation group, all the other each group excisions and ligation kidney are made the kidney of rats failure model, two weeks of clinical follow, survival rats is according to sex and body weight random packet again, every group 10, animal drinking water is the deionized water through sterilization, collects urine and the ight soil of postoperative in the time of the 22nd, 28,31,35,38 days, measures respectively.Get blood simultaneously, food-intake is measured and write down to separation of serum.Begin to give the above-mentioned special feed of rat until the experiment end after putting into metabolic cage.

Measuring method: the mensuration of (1) serum biochemistry index: the eye socket vein is got blood, and separation of serum is with the content of creatinine, blood urea nitrogen, inorganic phosphorus in automatic biochemical analyzer and the kit measurement serum; (2) mensuration of urine biochemical indicator: collect rat twenty-four-hour urine liquid with metabolic cage, record urine amount is with the content of creatinine, blood urea nitrogen, inorganic phosphorus in automatic biochemical analyzer and the kit measurement serum; (3) the ight soil content of inorganic phosphorus is measured: collect 24 hours ight soil of rat with metabolic cage, ashing, weigh, take by weighing certainweight and place centrifuge tube, add 10% perchloric acid, ambient temperature overnight, to extract inorganic phosphorus, get supernatant liquor after centrifugal, measure, calculate the content of inorganic phosphorus with automatic biochemical analyzer and test kit.

Statistical method: numeric representation is a means standard deviation; Organize a t check between model group and the pseudo-operation group and between four administration groups and the model group.

Table 1. is respectively organized rat blood serum inosine content (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	59.14±15.46	63.80±6.73	66.27±6.40	62.40±6.33	50.81±4.49							64.51±4.31
Model group							113.10±22.50 **	83.59±17.36 *	90.62±20.72 **	76.33±8.16 **	67.43±15.71 *	79.60±19.45 *
	The lime carbonate group	102.70±26.52	80.78±7.68	80.66±8.16	75.48±8.67	65.37±8.97							79.92±9.92
High dose group							91.86±13.04 *	83.14±12.41	80.07±10.22	75.17±9.66	69.07±10.47	75.7±10.39
	Middle dosage group	80.15±20.47 **	86.44±25.40	96.29±22.67	72.72±10.00	68.6±10.05							80.88±10.00
Low dose group							84.63±17.41 **	77.42±14.09	105.30±34.43	66.47±10.04 *	74.86±19.36	82.20±15.62

^*：p＜0.05， ^**：p＜0.01。

Table 2. is respectively organized rat blood serum urea nitrogen content (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	6.81±1.07	7.52±2.04	7.70±1.30	7.04±1.18	7.65±0.83							7.14±1.07
Model group							12.77±3.29 **	13.78±4.61 *	14.95±4.41 *	11.09±4.56 *	16.17±5.21 **	11.36±4.81 *
	The lime carbonate group	13.20±4.24	14.74±4.10	12.09±3.69	13.68±2.80	14.48±2.75							15.22±5.17
High dose group							11.98±2.19	13.78±4.01	9.78±2.54	10.79±3.43	13.88±4.29	13.24±6.75
	Middle dosage group	12.80±2.69	19.51±6.96 *	15.78±5.80	12.45±2.65	15.68±5.02							11.97±3.11
Low dose group							11.83±2.94	14.68±5.33	17.27±6.54	12.08±3.81	16.47±6.29	14.22±4.65

^*：p＜0.05， ^**：p＜0.01。

Table 3. is respectively organized rat blood serum content of inorganic phosphorus (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	2.43±0.34	2.33±0.70	2.57±0.38	2.46±0.34	2.43±0.24							2.83±0.31
Model group							2.16±0.21 *	1.87±0.40	2.4±0.37	2.41±0.41	2.19±0.38	2.56±0.32
	The lime carbonate group	2.13±0.32	2.00±0.53	2.44±0.76	2.26±0.51	2.15±0.21							2.46±0.36
High dose group							2.35±0.31	2.05±0.30	2.72±0.38	2.16±0.33	2.25±0.30	2.51±0.48
	Middle dosage group	2.64±0.19 **	1.98±0.62	2.65±0.71	2.24±0.28	2.08±0.27							2.61±0.54
Low dose group							2.59±0.28 **	1.93±0.44	2.64±1.24	2.41±0.57	2.23±0.59	2.63±0.37

^*：p＜0.05， ^**：p＜0.01。

Table 1～3 shows that model group is compared with pseudo-operation group, and its serum inosine and serum urea nitrogen level had significantly in operation and increase in back 16 days, and except that indivedual times, four administration groups are compared with model group does not all have significant difference (seeing Table 1～3).

Table 4. is respectively organized rat uric creatinine content (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	7258±2581	7137±2316	6792±2700	4442±1406	6268±1093							6227±826
Model group							6432±2778	5198±2922	4138±2155 *	2422±1309 **	2144±830 **	3346±1813 **
	The lime carbonate group	6434±2288	4320±2463	3251±1915	3046±1274	2715±2300							2781±2265
High dose group							4909±2513	4229±2245	4183±1599	2434±965	2538±903	2820±1378
	Middle dosage group	5682±3511	3498±2517	3470±2025	1762±616	1558±862							2245±821
Low dose group							4321±2550	3854±1578	3991±1704	2780±1084	2172±1143	2839±1447

^*：p＜0.05， ^**：p＜0.01。

Table 5. is respectively organized rat urinary urea nitrogen content (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	715.8±350.9	851.2±328.4	1406.4±467.3	999.3±259.3	1306.3±149.1							1098.1±148.9
Model group							617.2±317.6	839.9±376.9	641.2±269.6 **	486.5±201.1 **	616.8±137.2 **	743.3±288.5
	The lime carbonate group	604.8±266.6	712.9±305.9	522.±223.4	683.8±220.5	687.1±283.6							636.7±306.3
High dose group							520.9±314.5	856.5±340.7	778.9±167.5	640.4±215.1	694.7±189.9	612.8±165.5
	Middle dosage group	621.6±392.5	663.3±381.9	537.1±157.1	512.1±123.4	576.4±114.2							497.3±324.7
Low dose group							460.4±216.4	754.4±274.1	690.9±199.0	533.5±168.6	758.9±276.8	710.8±356.5

^*：p＜0.05， ^**：p＜0.01。

Table 6. is respectively organized rat urine content of inorganic phosphorus (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	59.01±27.98	46.92±16.38	64.57±22.53	53.61±9.58	47.03±9.42							53.58±7.60
Model group							57.01±29.69	13.78±4.61 *	41.15±14.56	40.53±13.33 *	20.29±16.26 **	32.39±13.45
	The lime carbonate group	54.20±24.56	14.74±4.10	11.73±8.33	9.60±6.47 **	21.14±20.95							8.80±4.02
High dose group							44.66±25.88	13.78±4.01	22.79±14.25	29.17±10.89	8.52±4.86	14.54±8.49
	Middle dosage group	59.13±34.50	19.51±6.96 *	20.66±12.28	23.59±12.41	9.39±3.95							10.59±7.43
Low dose group							42.76±16.03	14.68±5.33	29.31±10.29	31.68±11.06	8.77±2.82	16.89±10.00

^*：p＜0.05， ^**：p＜0.01。

Table 7. is respectively organized rat urine inorganic phosphorus output (μ mol/L) measurement result (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	20.18±6.41	21.63±9.94	21.64±5.22	20.46±5.94	20.21±6.42							21.49±5.63
Model group							17.10±5.66	17.14±6.25	14.18±5.28 **	15.44±4.33 **	13.08±8.97 *	13.67±4.53 **
	The lime carbonate group	11.11±3.01 **	2.68±1.97 **	4.41±2.69 **	5.15±3.88 **	5.43±3.91 *							3.76±1.16 **
High dose group							9.74±5.04 **	6.34±3.01 **	6.79±3.77 **	7.84±1.67 **	3.93±1.64 *	4.96±2.20 **
	Middle dosage group	12.07±3.86 *	9.06±6.32 *	7.37±4.29 **	8.55±4.11 **	4.56±2.15 *							5.28±2.39 **
Low dose group							15.55±3.16	11.19±4.58 *	9.30±2.80 *	12.32±4.60	5.17±2.67 *	8.84±5.56 *

^*：p＜0.05， ^**：p＜0.01。

Table 4～7 results show that model group is compared with pseudo-operation group, and creatinine level, urea level, inorganic phosphorus level and inorganic phosphorus output begin to have remarkable reduction in postoperative in its urine in the time of the 28th day.Four administration group uric creatinine levels are compared with model group with urea nitrogen levels does not all have significant difference (table 4,5).Four administration groups urine inorganic phosphorus level is compared part, and there were significant differences (table 6) with model group.Four administration groups urine inorganic phosphorus output is compared the low dose group of removing the 16th day, the 31st day with model group do not have significant difference, and all the other all significantly reduce (table 7).

Table 8. is respectively organized rat excrement inorganic phosphorus output (mg/24h) (n=10)

Group	Nephrectomy POD
						The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	41.801±9.505	43.945±7.542	45.716±5.900	45.608±7.810						51.159±7.857
Model group						44.283±8.727	49.421±7.733	49.851±8.201	47.954±7.547	49.900±10.494
	The lime carbonate group	87.941±19.280 **	91.183±21.520 **	96.082±20.626 **	100.187±9.866 **						102.980±10.683 **
High dose group						93.530±19.240 **	103.427±11.295 **	100.847±9.125 **	103.570±10.430 **	106.959±12.273 **
	Middle dosage group	70.814±12.060 **	83.475±12.971 **	80.832±10.668 **	84.907±15.225 **						96.283±18.596 **
Low dose group						68.955±8.420 **	72.880±8.852 **	75.433±10.839 **	79.564±12.984 **	75.832±8.386 **

^*：p＜0.05， ^**：p＜0.01。

Model group is compared with pseudo-operation group, and its excrement inorganic phosphorus output does not have significant difference.Four administration group excrement inorganic phosphorus outputs are compared with model group all to have and are significantly increased (table 8).Each is organized does not all have significant difference (table 9) between the rats eating amount.Each is organized between the rat inorganic phosphorus intake does not all have significant difference (table 10).

Table 9. is respectively organized rats eating amount (g/24h) (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	17.770±1.124	19.050±1.209	19.280±2.032	20.380±1.571	21.140±1.597							21.940±2.090
Model group							17.460±1.779	17.870±1.948	18.960±1.546	19.620±1.827	20.820±1.377	21.280±1.694
	The lime carbonate group	17.570±1.426	18.340±1.779	19.110±1.395	19.830±1.764	20.000±1.294							21.420±1.793
High dose group							17.540±1.469	18.810±1.315	18.720±2.222	20.550±2.270	21.120±1.284	21.920±1.996
	Middle dosage group	17.230±1.852	18.920±1.979	19.400±1.317	19.850±1.633	20.880±1.716							22.110±1.673
Low dose group							17.705±1.716	19.070±2.003	19.040±2.026	20.250±1.794	21.110±2.059	21.850±1.567

^*：p＜0.05， ^**：p＜0.01。

Table 10. is respectively organized rat inorganic phosphorus intake (mg/24h) (n=10)

Group	Nephrectomy POD
							The 16th day	The 22nd day	The 28th day	The 31st day	The 35th day	The 38th day
	Pseudo-operation group	131.320±8.303	140.780±8.938	142.479±15.019	150.608±11.611	156.225±11.804							162.137±15.447
Model group							129.029±13.147	132.059±14.393	140.114±11.428	144.992±13.500	153.860±10.173	157.259±12.521
	The lime carbonate group	126.680±10.281	132.231±12.827	137.783±10.056	142.974±12.722	151.410±9.333							154.438±14.236
High dose group							123.482±10.342	132.422±9.259	131.789±15.643	144.672±15.989	148.685±9.039	154.317±13.820
	Middle dosage group	124.228±13.351	136.413±14.270	139.874±9.498	143.119±11.790	150.545±12.376							159.413±12.062
Low dose group							129.247±12.529	139.211±14.620	138.992±14.786	147.825±13.096	154.103±15.029	159.505±12.133

^*：p＜0.05， ^**：p＜0.01。

Experiment conclusion: ferric citrate obviously increases renal failure rat excrement phosphorus output, reduce urine phosphorus output, and serum flesh liver and urea nitrogen levels does not have obvious change, and serum inorganic phosphorus content is compared also no significant difference with normal rat.Urine creatinine level and urea nitrogen levels do not have obvious change.

Pharmacokinetic

Ferric citrate produces and the similar calcium phosphate precipitation of aluminium salt by combining with phosphoric acid salt under one's belt.In intestines, be not absorbed.Ferric citrate is water miscible, and soluble iron is absorbable.As if the adjustment mechanism that inorganic iron is absorbed be present in the small intestinal cell.The small intestine rapid absorption is crossed by Tie Tong, and duodenum is the initial place that iron absorbs.The iron that great majority enter into mucomembranous cell can not be transported to blood plasma, but remains in the cell, drains when cell detachment and enters the abdominal cavity.

The zooscopy that the applicant utilizes rat to finish shows that after normal rat was taken in around the ferric citrate 4g/kg, the blood concentration of iron had slight rising (control group 1.26mg/ml, ferric citrate group 2.10mg/ml).Experimentation on animals has determined that ferric citrate is effective phosphate binders.The 1g ferric citrate can combine with the phosphoric acid salt of 40mg in the food, because bonding mechanism is a simple chemical reaction, the applicant thinks that the ferric citrate in human body has same bonding force.

Anxious malicious experimental study

On the prerun basis, get 70 of kunming mices (19～21g, male and female half and half), fasting is divided into 7 groups after 15 hours at random, 10 every group.With 4% starch paste ferric citrate is mixed with the even suspension of 7 kinds of concentration, 7 dosage groups are set, concentration is followed successively by from high to low: 10.00,8.00,6.40,5.12,4.10,3.28 and 2.62g/kg.Give mouse stomach respectively by 20ml/kg, observe and write down activity, feed, skin, mucous membrane, ight soil and the death condition of animal after the administration at once, and after administration, observe once every day at least in two weeks.Dead animal is carried out necrotomy, observe the changing conditions of each histoorgan.Calculate medium lethal dose with the Bliss method.The results are shown in following each table:

Each dosage treated animal death toll of table 1

Dosage (g/kg)	10.00	8.00	6.40	5.12	4.10	3.28	2.62
								Female	5	5	6	3	2	1	0
Male	5	5	3	4	3	2	0
								Amount to	10	10	8	7	5	3	0

Send out calculating medium lethal dose, LD with Bliss ₅₀=4.2821g/kg, the 95% credible 3.7019-4.8935g/kg of being limited to (seeing Table 2).

The oral ferric citrate acute toxicity of table 2 mouse LD ₅₀Reckoner (Bliss method)

Dosage	Log10 dose	Number of animals	Death toll	Mortality ratio	The experiment probability	Return probability
							(g/kg)	[Log(D)]	(only)	(only)	(％)	Unit (Y)	Unit (Y)
10.00	1.00000	10	10	100	-	7.6011
							8.00	0.90309	10	10	100	-	6.9168
6.40	0.80618	10	8	80	5.8415	6.2324
							5.12	0.70927	10	7	70	5.5240	5.5481
4.10	0.61278	10	5	50	5.0000	4.8667
							3.28	0.51587	10	3	30	4.4760	4.1823
2.62	0.41830	10	0	0	-	3.4933

Regression equation Y (Probit)=0.53937+7.0617 Log (D)

Medium lethal dose LD ₅₀=4.2821g/kg

LD ₅₀(Feiller correction) 95% fiducial limit=3.7019-4.8935g/kg

LD ₅＝2.5046g/kg

LD ₉₅＝7.3214g/kg

The LD of the oral ferric citrate of mouse ₅₀Be 4.28g/kg, animal does not have considerable change at once after administration, and the appearance activity reduces after about 1 hour, and state is dispirited, reactions such as expiratory dyspnea.Begin to occur dead after about 1.5 hours, death all occurred in after the medication within 24 hours.Dead animal is through dissecting, and each internal organs shows no obvious abnormalities.

Long malicious experimental study

The long-term toxicity test result of 96 weeks who adds the 0.12-0.06% ferric citrate in mouse drinking-water shows that compare with control group, ferric citrate group mouse is not found any tangible physiology and pathological change.Ferric citrate does not have carcinogenic potential yet.

Specific embodiments

Below the beneficial effect of further setting forth enforcement of the present invention and having by specific embodiment, be intended to help the reader to understand the essence of technical solution of the present invention better, but can not be interpreted as qualification the present invention's practical range.

Embodiment 1

300 mesh sieves (Chinese Industrial Standards (CIS) sieve, aperture 0.050mm) are crossed in the prior micronization of ironic hydroxide, take by weighing 1 equivalent, mix, add the purified water of 4 times of weight with Citric Acid 1.05 equivalents that contain a crystal water, make it in 60-65 ℃ of water-bath, to react, keep stirring, to avoid deposition.Because Citric Acid is dissolved in water and will absorbs heat, the mixing of two kinds of reactants does not have instant intense reaction.

Note in the reaction process keeping the skin wet, to keep the amount of reaction soln.The concentration and the proportion of resultant (ferric citrate) in the recording solution in the reaction process reacted about 70 hours, and the change in concentration of resultant is driven in constant, and reaction is finished.Suspended particulates are removed in reaction solution centrifugation under 4000rpm.Isolated clear liquid is removed moisture at 60 ℃ of heating evaporations.

The thick paste shape fluid that is condensed into is not placed and can spread lamellar out on the flat board of react with, 60 ℃ of oven dry down.

The also available hypobaric drying method of whole concentration process directly quickens to finish in reaction vessel.

The gained dry product is the thin flakey of puce, and quality is loose, very easily peels off, and almost can break away from container or flat board automatically in rocking.This crude product particle is crossed 10 mesh sieves, determine wherein citric acid radical content simultaneously 105.3%.

Above-mentioned crude product particle at room temperature soaks 2 hours (by per 10 grams with 80 milliliters of alcohol meters) under (25 ℃) or the lower temperature with 95% ethanol, with wherein residual Citric Acid stripping.With medium size filter paper or strainer filtering, or vacuum filtration, the particle that obtains is used ethanol elution once more, and obtain evenly shinny puce particle same the separation, measures wherein citric acid radical content 100.3%, yield 99.56%.

Ferric citrate content utilizes visible light instrument rapid determination (readable ferric citrate concentration range is at 0.1%-1.0%) in the above-mentioned preparation process: extract reaction solution and place centrifuge tube, under 4000rpm centrifugal 5 minutes, accurately measuring clear liquor suitably dilutes with purified water, reading under the 405nm in the visible light instrument, the concentration curve (1.0%-0.001%) of this numerical value that reads and ferric citrate standard substance is compared, can learn the relative concentration of reaction solution.

During reaction end, the proportion of reaction solution is 1.13, also can be used as reference.Measuring method is to draw the solution of 6-7cm with the kapillary of demarcating, and wipes away clean kapillary outer wall, the calculated specific gravity of weighing.

The content assaying method of citric acid radical in the ferric citrate after refining: measure the wherein content of iron (oxidation reduction process) earlier, calculate the due content of citric acid radical by 1: 1 molar ratio computing with the content of iron.

Use liquid chromatography for measuring citric acid radical content then, do external standard, measure citric acid radical content with Sodium Citrate.

Chromatographic condition is: chromatographic column: the ODS post; Moving phase: 0.5% phosphate aqueous solution, regulate pH=2.6 with ammonia solution; Flow velocity: 1ml/min; Detector: Uv@208nm

Embodiment 2

Embodiment 1 synthetic ferric citrate crude product soaks with ethyl acetate, and according to 70 milliliters of addings of per 10 grams, with the method refinement treatment of embodiment 12 times, yield 99.77%, citric acid radical content is 100.6% in the ferric citrate after refining.

Embodiment 3:

The pharmaceutical grade ferric citrate that adopts embodiment 1 or 2 to obtain is mixed with following preparation:

1) solution:

Ferric citrate 30 grams

Sodium Benzoate 0.2 gram

Sweeting agent is an amount of

Essence is an amount of

Glycerine is made 100 ml solns

2) syrup:

With sucrose and ferric citrate compatibility, sucrose and ferric citrate all are dissolved in the water make syrup, add other assistant agent then:

Ferric citrate 30 grams

Sorbic Acid 0.3 gram

Sucrose 66 grams

Essence is an amount of

Pure water is made 100 milliliters of syrup

3) gelifying agent:

With ferric citrate and the auxiliary material that can form gel make evenly, the glop or the semi-solid preparation of suspendible:

Ferric citrate 30 grams

Sodium Benzoate 0.2 gram

Sweeting agent is an amount of

Essence is an amount of

Sodium alginate is an amount of

Pure water is made 100 gram gels

4) capsule:

With ferric citrate and auxiliary material or do not add auxiliary material and be filled in Capsules or the soft capsule material and make:

Ferric citrate 500 grams

Microcrystalline Cellulose is an amount of

Talcum powder is an amount of

1000 of Capsuleses

6) granule:

Ferric citrate and suitable auxiliary material are made the dried particles shape preparation with certain particle size:

Ferric citrate 500 grams

Sucrose is an amount of

Polyoxyethylene glycol is an amount of

Make 1000 bags

7) tablet

With suitable auxiliary material uniform mixing, suppress disk shape or the special-shaped flaky solid preparation that forms by preparation technique:

Ferric citrate 500g

Starch 130g

Sodium starch glycolate 26g

3% hypromellose is an amount of

Magnesium Stearate 3.2g

Make 1000

8) powder

Become finely powdered with the ferric citrate pulverizing and by 120 order mesh screens:

Ferric citrate 500g

Direct packaging becomes the 0.5g/ bag, amounts to 1000 bags.

Claims (4)

1, a kind of preparation method of pharmaceutical grade ferric citrate comprises that the alcohols or the ketone that use 2-6 carbon soak to remove the treating process of residual Citric Acid and impurity the ferric citrate that has synthesized under room temperature or subambient temperature.

2, the described preparation method of claim 1, the alcohols of a described 2-6 carbon is 95% ethanol, treating process be with 95% ethanol at room temperature to more than the ferric citrate extraction once, the collecting precipitation thing.

3, claim 1 or 2 described preparation methods, it also comprises with ironic hydroxide and Citric Acid is the process of the synthetic ferric citrate of raw material, and wherein, the equivalence ratio of ironic hydroxide and Citric Acid is 1: 1.0-1: 1.05, temperature of reaction 60-70 ℃, synthetic product is in oven dry below 60 ℃.

4, the described preparation method of claim 3, when synthesizing ferric citrate, the reaction times is 48-72 hour.