Crystalline trimetrexate salts and the process for making the same

Abstract

The present invention provides for a crystalline form of trimetrexate either as a glucuronate, acetate, hydrochloride, methanosulfonate or lactate salt, which can be processed galenically as a stable, well-defined solid substance and processes for producing the crystalline forms. Such crystalline forms allow for prolonged stability in storage and for oral and intravenous administration of the drug.

Description

1. FIELD OF THE INVENTION

The present invention is directed to novel crystalline forms of trimetrexate salts and the novel processes for making crystalline trimetrexate salts.

2. BACKGROUND OF THE INVENTION

The 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline salts ("trimetrexate") are known to have antineoplastic, antiparasitic and antibacterial activity. Trimetrexate is a potent inhibitor of the enzyme dihydrofolate reductase ("DHFR") that is known to catalyze the synthesis of nucleotide precursors of DNA and RNA. Inhibition of this enzyme results in cellular depletion of reduced folates, which are necessary for various cellular process, including RNA and DNA synthesis, and ultimately results in cell death. It is this property that gives trimetrexate its antineoplastic, antiparasitic and antibacterial activity.

Trimetrexate has demonstrated antitumor activity against a range of experimental murine and human tumor cell lines, in vitro and in vivo. For example, trimetrexate has shown antitumor activity against murine cell lines such as L1210, L5178Y, S-180, W-256 in vitro. In addition, trimetrexate has shown antitumor activity against human tumor cells lines derived from breast, colon, lung, ovary, renal cell and melanoma cells in vitro. In vivo studies have demonstrated that trimetrexate has therapeutic utility against murine tumors such as B16 melanoma, colon 26 and 38, L1210 and p388 leukemia and CD8F mammary tumors. Other possible uses for trimetrexate include the treatment of malaria, psoriasis, rheumatoid arthritis and prophylaxis against Pneumocystis carinii pneumonia.

Trimetrexate as the free base is a lipophilic DHFR with very low water solubility. To increase the aqueous solubility the Warner-Lambert Company synthesized a number of various salts which were disclosed by Colbry in U.S. Pat. No. 4,376,858 and issued on Mar. 15, 1983 and assigned to the Warner-Lambert Company. The preferred salt reported by Colbry was trimetrexate glucuronate due to its superior water solubility, stability and low toxicity of glucuronic acid. The method disclosed by Colbry gives a method of preparation where trimetrexate and glucuronic acid are dissolved in warm methanol and ethyl acetate and followed by cooling to precipitate the salt. The Colbry patent states that the disclosed trimetrexate glucuronate salt is non-crystalline.

J. L. Hicks et al., J. Labelled Compound Radiopharm. 29, 415 (1991) disclose another method of manufacture of trimetrexate glucuronate salt. In this method trimetrexate free base and glucuronic acid are added to an aqueous solution in an ampoule, followed by lyophilization to form a solid. This method also produces an amorphous salt.

An injectable form of amorphous trimetrexate glucuronate has received marketing authorization in the United States and Canada under the trade name Neutrexin by U.S. Bioscience (West Conshohocken, Pa.) for use in combination with leucovorin for the treatment of moderate to severe Pneumocystis carinii pneumonia in immunocompromised patients, e.g., those suffering from AIDS (U.S. Bioscience's Neutrexin for PCP, Scripp 1886/87, 31(1994).

A. Hempel et al., Cancer Biochem. Biophys. 10, 25-30 (1988), discloses the crystal structures of trimetrexate acetate monohydrate and hydrated trimetrexate free base. There is no suggestion regarding crystalline trimetrexate glucuronate or the method of making the same.

H. K. Chan et al., J. Crystal Growth 94, 488-498 (1989) discloses techniques for modifying the crystallization of methotrexate. The presence of trimetrexate in solution was shown to affect the crystalline habit of the methotrexate that is precipitated. There is no suggestion regarding the crystallization of trimetrexate glucuronate.

P. L. Stetson et al., J. Chromatography 464, 163-171 (1989) discusses the stability of the trimetrexate glucuronate salt obtained from Warner Lambert/Parke-Davis, Pharmaceutical Research Division. This salt is apparently that obtained by the process disclosed in the U.S. Pat. No. 4,376,858, which is assigned to Warner Lambert. It indicates that the salt has a half-life in solution of 51.6.+-.0.8 days at 37.degree. C.

It is recognized that the amorphous form of trimetrexate salts is not the preferred form as a drug substance for oral administration. Accordingly, there is a strong need in the art for suitable methods for producing quantities of highly purified, medical grade trimetrexate salts having a crystalline structure, in order to obtain high and uniform stability during storage, and to provide oral forms of trimetrexate medications with good stability and bioavailability.

3. SUMMARY OF THE INVENTION

The present invention provides for crystalline forms of trimetrexate, either as a glucuronate, acetate, hydrochloride, methanesulfonate or lactate salt, which can be processed galenically as stable, well-defined solid substances. Such crystalline forms allow for prolonged stability in storage and for oral and intravenous administration of the drug.

Trimetrexate base is treated with a soft carbon acid, i.e, gluconic acid, glucuronic acid, lactic acid, acetic acid etc., but preferably gluconic acid, in either an aqueous or hydro-alcoholic solution to solubilize the free base. The trimetrexate solution is heated to between 40.degree. to 80.degree. C. and stirred until practically homogeneous, treated with charcoal and vacuum filtered. The filtrate is treated with an excess of either the desired acid or conjugate base of the acid to give the desired trimetrexate salt. The solution is cooled to 20.degree. C., filtered and the crystals washed with an appropriate solvent followed by drying under vacuum.

The present invention further provides for novel processes for producing crystalline trimetrexate salts of good quality. In one preferred embodiment, the present invention provides for a novel process for producing crystalline trimetrexate glucuronate salt of good quality. The process is characterized as follows:

a. water is used as a solvent; b. excess glucuronic acid is used to prevent the co-precipitation of the trimetrexate free base with the desired trimetrexate glucuronate salt; c. n-heptane is used in the water solution as an antifoaming agent; d. the crystalline trimetrexate glucuronate salt is filtered and washed with a 2% glucuronic acid solution; e. the salt is dried at an elevated temperature in the range of 40 to 50 degrees under vacuum so as to avoid decomposition of the salt, and the formation of lumps and agglomerates.

In another preferred embodiment, the present invention provides for a novel process for producing crystalline trimetrexate acetate hydrate salt of good quality. The process is characterized as follows:

a. ethanol, 20 to 30 percent in aqueous medium is used as a solvent to dissolve trimetrexate free base; b. excess gluconic acid is then added to form trimetrexate gluconate and to prevent the co-precipitation of the trimetrexate free base with the resulting trimetrexate gluconate salt; c. excess acetic acid is then added to convert the trimetrexate gluconate to the acetate salt; d. the crystalline trimetrexate acetate hydrate is filtered and washed with a 3 to 7 percent acetic acid solution; e. the salt is dried at an elevated temperature in the range of 70 to 80 degrees under vacuum so as to avoid decomposition of the salt, and to avoid the formation of lumps and agglomerates.

In a further preferred embodiment, the present invention provides for a novel process for producing crystalline trimetrexate hydrochloride hydrate salt of good quality. The process is characterized as follows:

a. water is used as a solvent to dissolve the trimetrexate free base; b. excess gluconic acid is then added to form trimetrexate gluconate and to prevent the co-precipitation of the trimetrexate free base with the resulting trimetrexate gluconate salt; c. excess sodium chloride is then added to convert the trimetrexate gluconate to the hydrochloride salt; d. the crystalline trimetrexate hydrochloride hydrate is filtered and washed with an aqueous ethanol solution of 75 to 85 percent; e. the salt is dried at an elevated temperature in the range of 70 to 80 degrees under vacuum so as to avoid decomposition of the salt, and the formation of lumps and agglomerates.

In a further preferred embodiment, the present invention provides for a novel process for producing crystalline trimetrexate methanesulfonate salt of good quality. The process is characterized as follows:

a. water is used as a solvent to dissolve the trimetrexate free base; b. excess gluconic acid is then added to form trimetrexate gluconate and to prevent the co-precipitation of the trimetrexate free base with the resulting trimetrexate gluconate salt; c. excess methanesulfonic acid is then added to convert the trimetrexate gluconate to the methanesulfonate salt; d. the crystalline trimetrexate methanesulfonate is filtered and washed with a water solution; e. the salt is dried at an elevated temperature in the range of 75 to 90 degrees under vacuum so as to avoid decomposition of the salt, and the formation of lumps and agglomerates.

In yet a further preferred embodiment, the present invention provides for a novel process for producing crystalline trimetrexate lactate hydrate salt of good quality. The process is characterized as follows:

a. water is used as a solvent to dissolve the trimetrexate free base; b. excess L-(+)-lactic acid is then added to convert the trimetrexate base to the lactate salt; c. the crystalline trimetrexate lactate hydrate is filtered and washed with a 50% aqueous ethanol solution to avoid yield losses due to the dissolution of the salt; d. the salt is dried at an elevated temperature in the range of 70 to 80 degrees under vacuum so as to avoid decomposition of the salt, and the formation of lumps and agglomerates.

4. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 exhibits the x-ray powder diffraction pattern of crystalline trimetrexate glucuronate hydrate salt of the present invention. The salt is crystalline, exhibiting measurable diffraction peaks. Cu radiation (1.54 .ANG.) is the x-ray source.

FIG. 2 exhibits the x-ray powder diffraction pattern of amorphous trimetrexate glucuronate salt produced by lyophilization. This salt exhibits no diffraction peaks and contains a hump in the two-theta range of 10.degree.-30.degree. which is characteristic of an amorphous material. Cu radiation (1.54 .ANG.) is the x-ray source.

FIG. 3 exhibits the differential scanning calorimetry scan of crystalline trimetrexate glucuronate hydrate salt of the present invention. The salt exhibits a sharp melting point at approximately 136.degree. C., closely followed by decomposition.

FIG. 4 exhibits the differential scanning calorimetry scan of amorphous trimetrexate glucuronate salt produced by lyophilization. This salt exhibits a broad melting range centered at 129.degree. C. and appears to decompose at high temperature at a slower rate.

FIG. 5 exhibits the differential scanning colorimetry scan of crystalline trimetrexate acetate hydrate salt of the present invention.

FIG. 6 exhibits the x-ray powder diffraction pattern of crystalline trimetrexate acetate hydrate salt of the present invention. Cu radiation (1.54 .ANG.) is the x-ray source.

FIG. 7 exhibits the differential scanning colorimetry scan of crystalline trimetrexate hydrochloride hydrate salt of the present invention.

FIG. 8 exhibits the x-ray powder diffraction pattern of crystalline trimetrexate hydrochloride hydrate salt of the present invention. Cu radiation (1.54 .ANG.) is the x-ray source.

FIG. 9 exhibits the differential scanning colorimetry scan of crystalline trimetrexate methanesulfonate salt of the present invention.

FIG. 10 exhibits the x-ray powder diffraction pattern of crystalline trimetrexate methanesulfonate salt of the present invention. Cu radiation (1.54 .ANG.) is the x-ray source.

FIG. 11 exhibits the differential scanning colorimetry scan of crystalline trimetrexate lactate hydrate salt of the present invention.

FIG. 12 exhibits the x-ray powder diffraction pattern of crystalline trimetrexate lactate hydrate salt of the present invention. Cu radiation (1.54 .ANG.) is the x-ray source.

5. DESCRIPTION OF THE PREFERRED EMBODIMENTS

It has been discovered that contamination and decreased yield of the trimetrexate salts can be avoided in part by careful control of the purity of the reagents used in the crystallization of the salt.

The purity of the glucuronic acid used in the preparation of the glucuronate and other crystalline salts should be high. Glucuronic acid is obtained either synthetically from glucose via a several step process or from natural products of flora, such as cherry gum (see, C. L. Mehltretter, et al. J. Amer. Chem. Soc. 73, 2424 (1951)). When synthetically prepared, the glucuronic acid may be contaminated by oxalate ions, calcium cations and reaction by-products. These contaminants should be removed by ion exchange or other suitable methods prior to use in the present crystallization process.

Likewise, the purity of the trimetrexate free base should be high. Possible contaminants of the trimetrexate free base include: 3, 4, 5-trimethoxyaniline, 2,4-diamino-5-methyl-6-quinazoline carboxaldehyde, 6-aminomethyl-5-methyl-2,4-quinazoline diamine, 2-amino-4-hydroxy-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline and 2,4-diamino-5-methyl-6-quinazoline hydroxymethyl.

The general process for producing crystalline trimetrexate glucuronate hydrate is as follows:

a. mix trimetrexate free base and glucuronic acid or a precursor of glucuronic acid in water at about 60.degree.-70.degree. C. until a homogeneous solution is formed; b. filter the homogeneous solution through a clarifying filter; c. cool the filtered solution down to about 40.degree. to about 50.degree. C.; d. add an anti-foaming agent such as heptane to the solution; e. cool the solution to about 20.degree. C. over 1 hour, then cool to 10.degree. C. for 1 hour and then to 5.degree. C. filter off trimetrexate glucuronate crystals and wash the crystals with about a 2% trimetrexate glucuronate solution to form a slurry; and f. stir the trimetrexate glucuronate slurry in acetone, filter and dry the crystals at about 50.degree. C. in vacuum.

A precursor of glucuronic acid useful in the above process is glucuronic acid-lactone, which can be hydrolyzed into glucuronic acid by reaction with water.

The preferred molar ratio of trimetrexate free base to the glucuronic acid or its precursor is from about 1.17 to about 1.22. An excess of the glucuronic acid is required to prevent the precipitation of the trimetrexate free base and ensure the complete conversion of this base to the salt. Too great an excess of the glucuronic acid, however, may cause the co-precipitation of the glucuronic acid. Further, a molar ratio of trimetrexate free base to the glucuronic acid of less than 1.17 results in greater difficulty in completely dissolving the trimetrexate free base in the water within a short period of time.

The amount of water used in dissolving the trimetrexate free base and the glucuronic acid is determined by the solubility of the reagents as well as the stirability of the solution. Preferably, the amount of water is about 500 ml of water per kilogram of the trimetrexate free base.

Preferably, n-heptane, octanol or toluene can be added to the aqueous solution to reduce foaming.

The solution is clarified by a clarifying medium selected from the group consisting of bentonite, montmorillorite or other acid washed bleaching earths or synthetic silica in order to remove colored impurities such as polar oxidation products.

Once the crystalline trimetrexate glucuronate hydrate salt is formed in the cooled solution, the salt is filtered to separate it from the solution. The filtered salt is washed with about 2% glucuronic acid solution to remove colored impurities and avoid dissolving the salt. The salt is then dried by slurrying in anhydrous acetone which should not contain more than 1% water, filtering and drying the salt in vacuum at about 50.degree. C. to a water content of about 3% to about 9% to thereby form the mono-, di- or trihydrate form of trimetrexate glucuronate hydrate salt. The temperature and length of time for drying are chosen so as to avoid decomposing the salt and to efficiently attain the correct water content.

Decomposition products present with the salt may be qualitatively analyzed by HPLC, thin layer chromatography or NMR analysis.

For the preparation of the acetate, hydrochloride and methanesulfonate salts of trimetrexate, it is preferred to first convert trimetrexate base to the gluconate salt by treatment with gluconic acid. The TMTX gluconate salt can be converted into the desired TMTX salt by treatment with the conjugate acid of that salt. Examples for the preparation of the various salts are given below.

Trimetrexate gluconate can be converted into trimetrexate acetate hydrate by treating the trimetrexate gluconate salt with a combination of excess of acetic acid and sodium acetate and at a temperature range from 70.degree. to 80.degree. C. The resulting trimetrexate acetate is then crystallized by cooling to a temperature ranging from 20.degree. to 25.degree. C., filtered and washed with acetic acid solution in a concentration range of from 3 to 7%, or another suitable solvent that avoids solvent losses during washing. In a preferred method, the trimetrexate gluconate salt is formed using an ethanol solvent and thereafter directly converted to the acetate.

Alternatively, the trimetrexate gluconate salt may be converted to trimetrexate hydrochloride hydrate, by treating the trimetrexate gluconate salt with an excess of sodium chloride and at a temperature range from 65.degree. to 75.degree. C. The resulting trimetrexate hydrochloride hydrate is then crystallized by cooling to a temperature ranging from 45.degree. to 55.degree. C., filtered and washed with 80% ethanol in water or another suitable solvent that avoids solvent losses during washing. In a preferred method, the trimetrexate gluconate salt is formed using an aqueous solvent and thereafter directly converted to the hydrochloride.

In another alternative, the trimetrexate gluconate salt may be converted to trimetrexate methanesulfonate, by treating the trimetrexate gluconate salt with an excess of methanesulfonic acid and at a temperature range from 80.degree. to 90.degree. C. The resulting trimetrexate methanesulfonate is then crystallized by cooling to a temperature ranging from 15.degree. to 25.degree. C., filtered and washed with water or another suitable solvent that avoids solvent losses during washing. In a preferred method, the trimetrexate gluconate salt is formed using an aqueous solvent and thereafter directly converted to the methanesulfonate.

In another alternative, the trimetrexate lactate hydrate salt may be formed by direct reaction by treating the trimetrexate base with an excess aqueous lactic acid solution. The resulting trimetrexate lactate hydrate is then crystallized by cooling to a temperature ranging from 0.degree. to 10.degree. C., filtered and washed with aqueous ethanol in a concentration range of from 45 to 55%, or another suitable solvent that avoids solvent losses during washing.

6. EXAMPLES

Example 1

Process for Producing Crystalline Trimetrexate D(+) Glucuronate Hydrate

33 L of purified water was heated in a vessel to 60.degree.-70.degree. C. 2.23 kgs (11.49 kg mol) of glucuronic acid was added to the warmed water, and 3.88 kg (10.50 kg mol) (based on the dry material) of trimetrexate base was charged. Thereafter 0.33 kgs of Tonsil was added and the mixture was pressure filtered at 50.degree.-70.degree. C. at a pressure of about 1 bar. The filtrate was cooled to 45.degree.-50.degree. C.

After stirring the filtrate for about 30 minutes at 45.degree.-50.degree. C., 0.1 L of n-heptane was added. The suspension was slowly cooled to 20.degree. C. over 1 hour, then cooled to 10.degree. C., stirred at this temperature for 1 hour and finally cooled to 5.degree. C.

The product was filtered off by vacuum and washed first with 3L of a 2% solution of glucuronic acid in purified water, and then with 5 L of acetone.

A vessel was charged with 25 L of acetone and the wet trimetrexate glucuronate hydrate obtained above was charged to form a slurry. The slurry was stirred at 20.degree.-25.degree. C. for 15 minutes and the product was again filtered off by vacuum and washed with 5 L of acetone to 7.0 kg of wet product.

The wet trimetrexate glucuronate hydrate was transferred into a cold vacuum dryer and dried at 20-30 mbar up to a maximum temperature of 50.degree. C. for 3-6 hours to give 4.80 kg of dry trimetrexate glucuronate hydrate (78% of theoretical yield based on trimetrexate free base). Thereafter the dried product was sieved (500.mu.) and if a tray dryer was used, also blended and filled into fiber drums with double PE bags as the insert. DSC max=136.degree. C. The water content was 4.26% (w/w) and the purity was assayed as 104% (w/w) by HPLC with reference to the anhydrous substance.

The dry product of trimetrexate glucuronate hydrate salt exhibits an x-ray powder diffraction pattern shown in FIG. 1 and a differential scanning calorimetry scan shown in FIG. 3. Table 1 indicates the peak positions and intensities of the x-ray powder diffraction pattern of crystalline trimetrexate glucoronate hydrate salt. Additionally, a sample of the dry product prepared as a mineral oil dispersion exhibits birefringence typical of crystalline materials.

Example 2

Process for Producing Trimetrexate Acetate Hydrate

62.0 g of Trimetrexate base hydrate (160 mMol) were slurried in 350 ml of ethanol and 100 ml of water. The mixture was heated to 70.degree. C. and 28 ml of a 50% aqueous gluconic acid solution (90 mMol), 7.5 ml of glacial acetic acid, 4 g of Tonsil and 0.5 g of activated charcoal were added. The mixture was then pressure filtered at 70.degree.-75.degree. C.

The clear brown solution was then charged with a solution of 6.5 g (80 mMol) of sodium acetate in 25 ml of water and then with 11 ml of glacial acetic acid at 70.degree.-75.degree. C.

The mixture was then cooled to 20.degree. C. The coarsely crystalline precipitate of the acetate salt was filtered off via a nutsche filter and washed with 50 ml of a 5% aqueous solution of acetic acid. After drying in a vacuum oven at 75.degree. C., 65.5 g (84% of the theoretical yield) of dark-yellow crystals were obtained. DSCmax=128.degree. C. (--H.sub.2 O), min=209.degree. C., 217.degree. C. The water content was 4.1% (w/w) and the purity was assayed at 99.3% (w/w) by titration with reference to the anhydrous substance.

The dry product of trimetrexate acetate hydrate exhibits the differential scanning colorimetry scan shown in FIG. 5, and the x-ray powder diffraction pattern shown in FIG. 6. Table 2 indicates the peak positions and intensities of the x-ray powder diffraction pattern of crystalline trimetrexate acetate hydrate salt.

Example 3

Process for Producing Trimetrexate Hydrochloride Hydrate

50 g of Trimetrexate base hydrate (130 mMol) were slurried in 500 ml of water and 72 ml of a 50% aqueous gluconic acid solution. The mixture was heated to 70.degree. C. and stirred until a homogeneous solution was obtained. After the addition of 1 g of activated charcoal the mixture was pressure filtered and cooled to 50.degree. C.

20 g of sodium chloride was added. The solution was then cooled to 20.degree. C. and stirred for one hour. The crystals were filtered off on a nutsche filter and washed two times with 50 ml of 80% ethanol. After drying in a vacuum oven at 75.degree. C. 48 g (90% of the theoretical yield) of the hydrochloride salt was obtained. DSCmax=148.degree. C., min=233.degree. C. The water content was 5.9% (w/w) and the purity was assayed at 98.7% (w/w) by titration with reference to the anhydrous substance. The dry product of trimetrexate hydrochloride hydrate exhibits the differential scanning colorimetry scan shown in FIG. 7, and the x-ray powder diffraction pattern shown in FIG. 8. Table 3 indicates the peak positions and intensities of the x-ray powder diffraction pattern of crystalline trimetrexate hydrochloride hydrate salt.

Example 4

Process for Producing Trimetrexate Methanesulfonate

77 g (200 mMol) of Trimetrexate base hydrate were slurried in 700 ml of deionized water. To the suspension were added 100 ml of 50% aqueous gluconic acid solution, 5 g of Tonsil and 5 g of activated charcoal. The mixture was heated to 50.degree. C. and pressure filtered.

The filtrate was then heated to 80.degree. C. and charged with 26.4 ml (400 mMol) of methanesulfonic acid). In the range of 80.degree. to 90.degree. C., a solution of 30 ml of 30% sodium hydroxide in 100 ml of water was added to adjust the pH to 4.2. After crystallization of the colorless methanesulfonate, the solution was cooled to 20.degree. C. The solid was filtered off on a nutsche filter and washed with water. After drying to a constant weight in a vacuum oven at 75.degree. to 90.degree. C. 89 g (95% of the theoretical yield) was obtained. DSCmax=239.degree. C, min=241.degree. C. and 290.degree. C. The water content was 0.2% (w/w) and the purity was assayed as 99.2% (w/w) by titration with reference to the anhydrous substance.

The dry product of trimetrexate methanesulfonate exhibits the differential scanning colorimetry scan shown in FIG. 9, and the x-ray powder diffraction pattern shown in FIG. 10. Table 4 indicates the peak positions and intensities of the x-ray powder diffraction pattern of crystalline trimetrexate methanesulfonate salt.

Example 5

Process for Producing Trimetrexate Lactate Hydrate

13 g (34 mMol) of Trimetrexate base hydrate and 3.5 ml of an 85% aqueous solution of L-(+)-lactic acid (40 mMol) were dissolved in 100 ml of water by heating to 40.degree. C. A pressure filter filtration with 1 g of activated charcoal and 1 g of Tonsil was performed at this temperature.

100 ml of ethanol were added to the filtrate and the mixture was then cooled to 5.degree. C. The precipitated solid was filtered off and washed with 20 ml of 50% aqueous ethanol.

After drying in vacuo at 75.degree. C. 13.1 g (81% of the theoretical yield) of the pale yellow lactate salt was obtained. DSCmax=196.degree. C. and 208.degree. C., min=198.degree. C. The water content was 3.3% (W/W) and the purity was assayed as 99.2% (w/w) by titration with reference to the anhydrous substance.

The dry product of trimetrexate lactate hydrate exhibits the differential scanning colorimetry scan shown in FIG. 11, and the x-ray powder diffraction pattern shown in FIG. 12. Table 5 indicates the peak positions and intensities of the x-ray powder diffraction pattern of crystalline trimetrexate lactate hydrate salt.

PARAMETERS

Molar ratios for raw materials and reagents vary typically .+-.3%

A .+-.5% variation is an operational allowance for all solvent measurements unless otherwise stated.

The additions "about" and "approx." indicate that the quantities may vary in a broader range.

Times are approximate and may vary .+-.5% unless otherwise stated.

Tolerance for temperature is .+-.5.degree. C. unless otherwise stated.

For pressure, a variation range of .+-.10% is allowed unless otherwise stated.

pH may vary .+-.1 pH unit unless otherwise stated. If pH is exceeded during adjustment it may be corrected using an appropriate acid or base.

TABLE 1______________________________________Date: 6-DEC-93 Time: .sub.-- :51:46EXTENDED OUTPUT FROM THE PEAK LOCATE PROGRAMSample ID: TRIMETREXATE-GLUCORONATE BATCH NO. 93-07231File: HEU06.RAW D/I File: HEU06.DIFDate & time of measurement: 03-DEC-93 10:21:49FILE MEASUREMENT PARAMETERS:RANGE Start angle: Stop angle: 80.000 Step: 0.050 Count#1 2.000 time:Diffractometer: 1-A Scan: STEP SCANSpecified parameters: Method = Trend-orientedSensitivity factor = 2.00The smallest peak relative to the largest = 0.50%Alpha-2 removalAlpha-1/alpha-2 ratio = 2.00Calibration of 2-thetaSERIES #1No 2Theta d Rel I (%) Max I Integ I Width Type______________________________________Range #11 4.473 19.7411 100.0 309. 1531.94 0.248 KA12 6.348 13.9127 41.5 128. 468.33 0.182 KA13 8.990 9.8289 51.6 160. 1210.00 0.379 KA14 10.086 8.7627 12.6 39. 176.94 0.228 KA15 12.711 6.9584 9.3 29. 198.89 0.344 KA16 13.517 6.5454 51.1 158. 1063.61 0.336 KA17 14.286 6.1949 30.8 95. 574.17 0.301 KA18 16.290 5.4369 6.5 20. 112.78 0.281 KA19 18.061 4.9075 27.0 84. 589.44 0.353 KA110 22.698 3.9145 10.2 31. 179.44 0.286 KA111 69.486 1.3516 3.8 12. 32.22 0.138 KA1______________________________________ TABLE 2______________________________________Date: 22-DEC-94 Time: 12:47:38EXTENDED OUTPUT FROM THE PEAK LOCATE PROGRAMSample ID: LO7 92-11926File: USB27.RAW D/I File: USB27.DIFDate & time of measurement: 22-DEC-94 11:36:33FILE MEASUREMENT PARAMETERS:RANGE Star angle: Stop angle: 40.000 Step: 0.050 Count#1 4.000 time:Diffractometer: 1-A Scan: STEP SCANSpecified parameters: Method = Trend-orientedSensitivity factor = 2.00The smallest peak relative to the largest = 0.50%Alpha-2 removalAlpha-1/alpha-2 ratio = 2.00Calibration of 2-thetaSERIES #1No 2Theta d Rel I (%) Max I Integ I Width Type______________________________________Range #11 5.049 17.4873 3.0 66. 94.44 0.071 KA12 5.401 16.3488 19.8 441. 1377.22 0.156 KA13 10.604 8.3359 54.9 1218. 4812.06 0.221 KA14 10.800 8.1851 100.0 2221. 7485.72 0.169 KA15 11.592 7.6278 27.4 609. 2614.17 0.215 KA16 12.504 7.0731 7.5 166. 570.00 0.172 KA17 13.546 6.5315 5.1 114. 438.06 0.192 KA18 13.900 6.3660 6.0 133. 366.67 0.138 KA19 15.077 5.8717 6.0 134. 332.78 0.124 KA110 15.353 5.7664 19.5 434. 1590.28 0.183 KA111 16.234 5.4555 24.4 543. 2397.11 0.238 KA112 16.500 5.3682 35.7 794. 2926.23 0.184 KA113 17.674 5.0143 11.5 256. 893.33 0.174 KA114 18.416 4.8137 6.9 153. 525.00 0.171 KA115 19.167 4.6269 5.9 130. 367.78 0.141 KA116 20.049 4.4253 7.8 173. 785.56 0.227 KA117 21.140 4.1992 16.1 357. 2059.44 0.289 KA118 21.679 4.0961 7.0 156. 200.35 0.116 KA119 21.896 4.0560 16.9 376. 1767.43 0.235 KA120 22.902 3.8801 31.8 707. 3481.67 0.246 KA121 23.312 3.8126 14.8 329. 1003.33 0.152 KA122 23.998 3.7052 9.0 199. 871.99 0.242 KA123 24.105 3.6890 12.0 267. 771.34 0.144 KA124 24.507 3.6294 8.4 186. 461.39 0.124 KA125 24.963 3.5642 6.0 134. 353.33 0.132 KA126 25.216 3.5290 2.3 51. 126.11 0.123 KA127 25.657 3.4694 45.7 1015. 5032.78 0.248 KA128 26.722 3.3334 13.8 305. 1221.94 0.200 KA129 27.198 3.2761 10.3 228. 805.56 0.177 KA130 27.548 3.2353 10.0 222. 671.39 0.151 KA131 28.140 3.1686 8.4 187. 606.99 0.175 KA133 29.541 3..sub.-- 214 1.4 31. 51.67 0.082 KA134 31.471 2..sub.-- 403 1.2 27. 92.22 0.168 KA135 34.406 2.6045 2.5 55. 179.72 0.163 KA136 37.820 2.3769 2.9 64. 270.00 0.209 KA137 38.356 2.3449 3.8 84. 281.39 0.168 KA1______________________________________ TABLE 3______________________________________Date: 22-DEC-94 Time: 12:49:55EXTENDED OUTPUT FROM THE PEAK LOCATE PROGRAMSample ID: LO7 92-11927File: USB28.RAW D/I File: USB28.DIFDate & time of measurement: 22-DEC-94 11:59:09FILE MEASUREMENT PARAMETERS:RANGE Start angle: Stop angle: 40.000 Step: 0.05 Count#1 4.000 time: 1Diffractometer: 1-A Scan: STEP SCANSpecified parameters: Method = Trend-orientedSensitivity factor = 2.00The smallest peak relative to the largest = 0.50%Alpha-2 removalAlpha-1/alpha-2 ratio = 2.00Calibration of 2-thetaSERIES #1No 2Theta d Rel I (%) Max I Integ I Width Type______________________________________Range #11 8.100 10.9064 14.2 181. 555.83 0.153 KA12 8.772 10.0726 33.1 422. 1858.33 0.220 KA13 10.357 8.5341 100.0 1277. 5850.56 0.229 KA14 11.910 7.4249 3.0 39. 56.39 0.073 KA15 15.182 5.8310 1.4 18. 56.11 0.155 KA16 15.568 5.6873 61.3 783. 3116.94 0.199 KA17 17.299 5.1221 2.9 37. 110.28 0.150 KA18 18.539 4.7821 9.3 119. 508.06 0.214 KA19 19.055 4.6538 1.7 22. 30.00 0.069 KA110 20.811 4.2648 98.1 1252. 5814.44 0.232 KA111 21.397 4.1494 2.9 37. 86.11 0.117 KA112 22.658 3.9213 1.1 14. 25.28 0.092 KA113 22.893 3.8816 2.0 25. 68.89 0.137 KA114 23.424 3.7947 18.6 237. 1412.78 0.298 KA115 25.393 3.5048 2.9 37. 61.11 0.083 KA116 25.917 3.4350 5.1 65. 143.19 0.155 KA117 26.030 3.4204 7.2 92. 338.75 0.185 KA118 27.510 3.2397 21.9 280. 1365.56 0.244 KA119 28.824 3.0949 5.3 68. 241.67 0.178 KA120 31.541 2.8342 0.5 6. 26.67 0.207 KA1______________________________________ TABLE 4______________________________________Date: 22-DEC-94 Time: 13:07:28EXTENDED OUTPUT FROM THE PEAK LOCATE PROGRAMSample ID: LO7 92-11929File: USB30.RAW D/I File: USB30.DIFDate & time of measurement: 22-DEC-94 12:41:39FILE MEASUREMENT PARAMETERS:RANGE Start angle: Stop angle: 40.000 Step: 0.050 Count#1 4.000 time:Diffractometer: 1-A Scan: STEP SCANSpecified parameters: Method = Trend-orientedSensitivity factor = 2.00The smallest peak relative to the largest = 0.50%Alpha-2 removalAlpha-1/alpha-2 ratio = 2.00Calibration of 2-thetaSERIES #1No 2Theta d Rel I (%) Max I Integ I Width Type______________________________________Range #11 7.541 11.7132 100.0 1725. 7379.44 0.214 KA12 9.196 9.6093 9.2 158. 617.78 0.195 KA13 11.007 8.0317 32.0 553. 2370.00 0.214 KA14 12.036 7.3475 12.1 208. 810.56 0.195 KA15 15.159 5.8401 47.0 811. 4142.64 0.257 KA16 15.337 5.7724 13.1 226. 480.14 0.106 KA17 15.993 5.5372 6.7 116. 381.67 0.164 KA18 16.473 5.3770 3.7 64. 211.67 0.165 KA19 17.799 4.9794 13.0 224. 978.33 0.218 KA110 18.521 4.7867 19.2 331. 1376.16 0.225 KA111 18.657 4.7521 19.8 342. 942.73 0.138 KA112 20.571 4.3140 9.5 165. 508.33 0.154 KA113 21.060 4.2150 1.9 32. 59.44 0.092 KA114 22.744 3.9067 9.1 157. 710.92 0.241 KA115 22.856 3.8878 9.0 155. 339.91 0.110 KA116 23.969 3.7096 29.1 502. 2503.89 0.249 KA117 24.653 3.6083 4.4 76. 191.94 0.126 KA118 25.405 3.5032 5.1 87. 342.22 0.196 KA119 25.988 3.4258 2.1 36. 107.50 0.147 KA120 26.328 3.3823 9.3 161. 685.00 0.212 KA121 27.503 3.2405 2.8 48. 143.61 0.151 KA122 27.832 3.2030 4.7 82. 360.00 0.221 KA123 28.906 3.0863 2.7 46. 131.39 0.142 KA124 29.807 2.9950 2.2 37. 71.11 0.095 KA125 30.463 2.9320 1.7 29. 60.56 0.103 KA126 33.219 2.6948 2.0 34. 120.56 0.177 KA127 34.569 2.5926 1.0 18. 49.44 0.140 KA128 35.656 2.5160 1.1 19. 53.33 0.140 KA1______________________________________ TABLE 5______________________________________Date: 22-DEC-94 Time: 12:53:01EXTENDED OUTPUT FROM THE PEAK LOCATE PROGRAMSample ID: LO7 92-11928File: USB29.RAW D/I File: USB29.DIFDate & time of measurement: 22-DEC-94 12:20:33FILE MEASUREMENT PARAMETERS:RANGE Start angle: Stop angle: 40.000 Step: 0.050 Count#1 4.000 time: 1Diffractometer: 1-A Scan: STEP SCANSpecified parameters: Method = Trend-orientedSensitivity factor = 2.00The smallest peak relative to the largest = 0.50%Alpha-2 removalAlpha-1/alpha-2 ratio = 2.00Calibration of 2-thetaSERIES #1No 2Theta d Rel I (%) Max I Integ I Width Type______________________________________Range #11 4.894 18.0405 8.0 69. 227.78 0.164 KA12 7.528 11.7334 100.0 866. 3915.00 0.226 KA13 9.805 9.0140 46.9 406. 1807.78 0.222 KA14 11.360 7.7830 63.8 553. 2597.22 0.235 KA15 12.816 6.9016 28.2 244. 985.56 0.202 KA16 14.730 6.0092 19.4 168. 608.33 0.181 KA17 15.662 5.6534 84.4 731. 3580.56 0.245 KA18 17.071 5.1900 9.0 78. 253.89 0.162 KA19 18.353 4.8301 16.5 143. 502.22 0.176 KA110 19.700 4.5029 45.8 396. 2038.61 0.257 KA111 20.500 4.3288 2.9 25. 39.17 0.078 KA112 20.745 4.2782 2.8 24. 38.61 0.079 KA113 20.957 4.2355 10.7 92. 235.00 0.127 KA114 21.407 4.1475 16.7 145. 535.56 0.185 KA115 22.110 4.0172 4.8 41. 88.89 0.108 KA116 22.834 3.8915 6.9 60. 183.33 0.154 KA117 23.062 3.8535 9.7 84. 154.17 0.092 KA118 23.950 3.7125 3.0 26. 78.89 0.151 KA119 24.245 3.6680 24.0 208. 746.67 0.180 KA120 24.682 3.6041 29.2 253 913.89 0.181 KA121 25.055 3.5513 1.6 14. 13.89 0.050 KA122 25.341 3.5119 8.5 74. 283.89 0.193 KA123 26.244 3.3930 16.8 145. 613.33 0.211 KA124 27.296 3.2646 7.6 65. 233.33 0.178 KA125 28.801 3.0973 3.2 28. 63.89 0.115 KA126 29.351 3.0405 2.0 17. 42.78 0.124 KA127 33.687 2.6585 4.5 39. 117.78 0.152 KA128 34.292 2.6129 1.5 13. 20.00 0.077 KA129 34.814 2.5749 5.0 44. 150.56 0.173 KA130 35.305 2.5402 5.6 48. 166.67 0.172 KA131 36.894 2.4343 3.6 31. 57.22 0.091 KA1______________________________________

The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.

All references cited in the present application are incorporated by reference in their entirety.

Claims

1. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline glucuronate hydrate.

2. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline glucuronate hydrate according to claim 1 wherein the glucuronate is D(+)glucuronate.

3. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline glucuronate hydrate according to claim 2 having an x-ray powder diffraction pattern essentially the same as FIG. 1.

4. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline glucuronate hydrate according to claim 2 having an x-ray powder diffraction pattern essentially the same as the following table:

______________________________________ d Rel I (%)______________________________________ 19.7411 100.0 13.9127 41.5 9.8289 51.6 8.7627 12.6 6.9584 9.3 6.5454 51.1 6.1949 30.8 5.4369 6.5 4.9075 27.0 3.9145 10.2 1.3516 3.8.______________________________________

5. A method of producing crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline glucuronate hydrate comprising the steps of:

a. mixing trimetrexate free base and glucuronic acid or a precursor of glucuronic acid in water at a temperature range from about 60.degree.-70.degree. C. to form a solution to produce trimetrexate glucuronate hydrate salt;

b. cooling the solution to about 40.degree. C. to about 50.degree. C.;

c. passing the cooled solution through a clarifying medium; and

d. cooling the clarified solution to about 20.degree. C. over 1 hour, then cooled to 10.degree. C. for 1 hour and then to 5.degree. C. to allow the crystallization of the trimetrexate glucuronate hydrate salt.

6. The method of claim 5 wherein the molar ratio of trimetrexate free base and glucuronic acid is from about 1.17 to about 1.22.

7. The method of claim 5 wherein the precursor of glucuronic acid is selected from the group consisting of glucuronic acid-.gamma.-lactone and glucuronic acid monoacetonide.

8. The method of claim 5 wherein the solution in step a) further comprises an anti-foaming agent selected from the group consisting of n-heptane, octanol and toluene.

9. The method of claim 5 wherein the clarifying medium is selected from the group consisting of bentonite and montmorillonite.

10. The method of claim 5 where the crystalline trimetrexate glucuronate hydrate salt of step d) is separated from the solution and washed with about 2% glucuronic acid solution.

11. The method of claim 10 where the washed crystalline trimetrexate glucuronate hydrate salt is dried to a water content of about 3 to about 9%.

12. The method of claim 11 where the crystalline trimetrexate glucuronate hydrate salt is dried by slurrying in acetone, separating the salt from the acetone and drying the salt in vacuum.

13. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline acetate hydrate having an x-ray powder diffraction pattern essentially the same as the following table:

______________________________________ d Rel I (%)______________________________________ 17.4873 3.0 16.3488 19.8 8.3359 54.9 8.1851 100.0 7.6278 27.4 7.0731 7.5 6.5315 5.1 6.3660 6.0 5.8717 6.0 5.7664 19.5 5.4555 24.4 5.3682 35.7 5.0143 11.5 4.8137 6.9 4.6269 5.9 4.4253 7.8 4.1992 16.1 4.0961 7.0 4.0560 16.9 3.8801 31.8 3.8126 14.8 3.7052 9.0 3.6890 12.0 3.6294 8.4 3.5642 6.0 3.5290 2.3 3.4694 45.7 3.3334 13.8 3.2761 10.3 3.2353 10.0 3.1686 8.4 3.0214 1.4 2.8403 1.2 2.6045 2.5 2.3769 2.9 2.3449 3.8.______________________________________

14. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline acetate hydrate having an x-ray powder diffraction pattern essentially the same as FIG. 6.

15. A method of producing crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline acetate hydrate comprising the steps of:

a. mixing trimetrexate free base and gluconic acid or a precursor of gluconic acid in ethanol and warming said mixture to about 70.degree. C.;

b. adding glacial acetic acid to said mixture;

c. passing said mixture through a clarifying medium and adding sodium acetate to said clarified mixture to produce trimetrexate acetate hydrate salt; and

d. cooling the clarified mixture to about 20.degree. C. to allow the crystallization of the trimetrexate acetate hydrate salt.

16. The method of claim 15 wherein the molar ratio of trimetrexate free base and gluconic acid is from about 2 to about 1.

17. The method of claim 15 wherein the precursor of gluconic acid is selected from the group consisting of gluconic acid-lactone and gluconic acid monoacetonide.

18. The method of claim 15 wherein the clarifying medium is selected from the group consisting of bentonite and montmorillonite.

19. The method of claim 15 where the crystalline trimetrexate acetate hydrate salt of step d) is separated from the solution and washed with about 5% acetic acid solution.

20. The method of claim 19 where the washed crystalline trimetrexate acetate hydrate salt is dried to a water content of about 3.5 to about 5%.

21. The method of claim 20 where the crystalline trimetrexate acetate hydrate salt is dried by separating the salt from the acetic acid solution and drying the salt in vacuum.

22. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethyoxyanilino)methyl!quinazoline hydrochloride hydrate having an x-ray powder diffraction pattern essentially the same as the following table:

______________________________________ d Rel I (%)______________________________________ 10.9064 14.2 10.0726 33.1 8.5341 100.0 7.4249 3.0 5.8310 1.4 5.6873 61.3 5.1221 2.9 4.7821 9.3 4.6538 1.7 4.2648 98.1 4.1494 2.9 3.9213 1.1 3.8816 2.0 3.7947 18.6 3.5048 2.9 3.4350 5.1 3.4204 7.2 3.2397 21.9 3.0949 5.3 2.8342 0.5.______________________________________

23. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline hydrochloride hydrate having an x-ray powder diffraction pattern essentially the same as FIG. 8.

24. A method of producing crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline hydrochloride hydrate comprising the steps of:

a. mixing trimetrexate free base and gluconic acid or a precursor of gluconic acid in water and warming said mixture to about 70.degree. C.;

b. passing said mixture through a clarifying medium and adding sodium chloride to said clarified mixture to produce trimetrexate hydrochloride hydrate salt;

c. cooling the clarified mixture to about 20.degree. C. to allow the crystallization of the trimetrexate hydrochloride hydrate salt.

25. The method of claim 24 wherein the molar ratio of trimetrexate free base and gluconic acid is from about 1 to about 2.

26. The method Of claim 24 wherein the precursor of gluconic acid is selected from the group consisting of gluconic acid-lactone and gluconic acid monoacetonide.

27. The method of claim 24 wherein the clarifying medium is selected from the group consisting of bentonite and montmorillonite.

28. The method of claim 24 where the crystalline trimetrexate hydrochloride hydrate salt of step c) is separated from the solution and washed with about 80% ethanol solution.

29. The method of claim 28 where the washed crystalline trimetrexate hydrochloride hydrate salt is dried to a water content of about 3.5 to about 8%.

30. The method of claim 29 where the crystalline trimetrexate hydrochloride hydrate salt is dried by separating the salt from the ethanol solution and heating the salt in vacuum.

31. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline methanesulfonate having an x-ray powder diffraction pattern essentially the same as the following table:

______________________________________ d Rel I (%)______________________________________ 11.7132 100.0 9.6093 9.2 8.0317 32.0 7.3475 12.1 5.8401 47.0 5.7724 13.1 5.5372 6.7 5.3770 3.7 4.9794 13.0 4.7867 19.2 4.7521 19.8 4.3140 9.5 4.2150 1.9 3.9067 9.1 3.8878 9.0 3.7096 29.1 3.6083 4.4 3.5032 5.1 3.4258 2.1 3.3823 9.3 3.2405 2.8 3.2030 4.7 3.0863 2.7 2.9950 2.2 2.9320 1.7 2.6948 2.0 2.5926 1.0 2.5160 1.1.______________________________________

32. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline methanesulfonate having an x-ray powder diffraction pattern essentially the same as FIG. 10.

33. A method of producing, crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline methanesulfonate comprising the steps of:

a. mixing trimetrexate free base and gluconic acid or a precursor of gluconic acid to form a mixture and warming said mixture to about 50.degree. C.;

b. passing said mixture through a clarifying medium, warming said clarified mixture to about 80.degree. C. and adding sodium methanesulfonic acid to said warmed clarified mixture to produce trimetrexate methanesulfonate salt;

c. cooling the mixture to about 20.degree. C. to allow the crystallization of the trimetrexate methanesulfonate salt.

34. The method of claim 33 wherein the molar ratio of trimetrexate free base and gluconic acid is from about 2 to about 3.

35. The method of claim 33 wherein the precursor of gluconic acid is selected from the group consisting of gluconic acid-.gamma.-lactone and gluconic acid monoacetonide.

36. The method of claim 33 wherein the clarifying medium is selected from the group consisting of bentonite and montmorillonite.

37. The method of claim 33 where the crystalline trimetrexate methanesulfonate salt of step c) is separated from the solution and washed with about 30% sodium hydroxide solution.

38. The method of claim 37 where the washed crystalline trimetrexate methanesulfonate salt is dried to a water content of about 0 to about 1%.

39. The method of claim 38 where the crystalline trimetrexate methanesulfonate salt is dried by separating the salt from the sodium hydroxide solution and drying the salt in vacuum.

40. A crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline lactate hydrate having an x-ray powder diffraction pattern essentially the same as the following table:

______________________________________ d Rel I (%)______________________________________ 18.0405 8.0 11.7334 100.0 9.0140 46.9 7.7830 63.8 6.9016 28.2 6.0092 19.4 5.6534 84.4 5.1900 9.0 4.8301 16.5 4.5029 45.8 4.3288 2.9 4.2782 2.8 4.2355 10.7 4.1475 16.7 4.0172 4.8 3.8915 6.9 3.8535 9.7 3.7125 3.0 3.6680 24.0 3.6041 29.2 3.5513 1.6 3.5119 8.5 3.3930 16.8 3.2646 7.6 3.0973 3.2 3.0405 2.0 2.6585 4.5 2.6129 1.5 2.5749 5.0 2.5402 5.6 2.4343 3.6.______________________________________

41. The crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline lactate hydrate having an x-ray powder diffraction pattern essentially the same as FIG. 12.

42. A method of producing crystalline 2,4-diamino-5-methyl-6-�(3,4,5-trimethoxyanilino)methyl!quinazoline lactate hydrate comprising the steps of:

a. mixing trimetrexate free base and lactic acid to form a mixture and warming said mixture to about 40.degree. C. to produce trimetrexate lactate hydrate salt;

b. passing said mixture through a clarifying medium;

c. cooling the clarified mixture to about 5.degree. C. to allow the crystallization of the trimetrexate lactate hydrate salt.

43. The method of claim 42 wherein the molar ratio of trimetrexate free base and lactic acid is from about 1 to about 2.

44. The method of claim 42 wherein the clarifying medium is selected from the group consisting of bentonite and montmorillonite.

45. The method of claim 42 where the crystalline trimetrexate lactate hydrate salt of step c) is separated from the solution and washed with about 50% ethanol solution.

46. The method of claim 45 where the washed crystalline trimetrexate lactate hydrate salt is dried to a water content of about 3.5 to about 5%.

47. The method of claim 46 where the crystalline trimetrexate lactate hydrate salt is dried by separating the salt from the ethanol solution and drying the salt in vacuum.