Cocrystal of Telmisartan and Hydrochlorothiazide

Abstract

The present disclosure relates to a cocrystal of telmisartan and hydrochlorothiazide, a preparation method and use thereof. In the cocrystal, the molar ratio of telmisartan and hydrochlorothiazide is 1:1. The cocrystal of telmisartan and hydrochlorothiazide was characterized by X-ray powder diffraction (XRPD), proton nuclear magnetic resonance spectra (1H-NMR), thermal gravimetric analysis (TG), scanning differential calorimetry (DSC) and infrared (IR) spectra, and it was found that the maximum plasma concentration of the cocrystal in SD rats was higher than that of any one of hydrochlorothiazide and telmisartan itself. The cocrystal of telmisartan and hydrochlorothiazide has a simple preparation method and good physical and chemical properties.

Claims

1. A cocrystal of telmisartan and hydrochlorothiazide, characterized in that the molar ratio of telmisartan and hydrochlorothiazide in the cocrystal is 1:1.

2. The cocrystal of telmisartan and hydrochlorothiazide according to claim 1, characterized in that, in the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide, characteristic peaks exist at the 2 angle of about 5.560.2, 9.960.2, 11.130.2, 14.680.2, 15.470.2, 17.720.2, 18.350.2, 19.430.2.

3. The cocrystal of telmisartan and hydrochlorothiazide according to claim 1, characterized in that, in the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide, characteristic peaks exist at the 2 angle of about 5.560.2, 7.410.2, 9.960.2, 11.130.2, 12.300.2, 14.680.2, 15.470.2, 17.720.2, 18.350.2, 19.430.2, 21.200.2, 22.150.2, 24.300.2, 24.810.2.

4. The cocrystal of telmisartan and hydrochlorothiazide according to claim 1, characterized in that, the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide is shown substantially as the XRPD pattern of FIG. 1.

5. The cocrystal of telmisartan and hydrochlorothiazide according to claim 1, characterized in that, a characteristic melting peak at about 199.020.2 C. exists in the differential scanning calorimetry spectrum of the cocrystal of telmisartan and hydrochlorothiazide.

6. A preparation method for the cocrystal of telmisartan and hydrochlorothiazide of claim 1, the method is one of the following methods: Method I: The method I comprises the following steps: (a) dissolving the hydrochlorothiazide in an organic solvent to prepare a saturated solution of hydrochlorothiazide; (b) dissolving separately the telmisartan in the same organic solvent as that in step (a) to prepare a saturated solution of telmisartan; (c) mixing and stirring the saturated solution of hydrochlorothiazide in the step (a) and the saturated solution of telmisartan in the step (b), thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (d) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (c), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide; Method II: The method II comprises the following steps: (e) dissolving the hydrochlorothiazide in an organic solvent to prepare a saturated solution of hydrochlorothiazide; (f) adding a telmisartan powder to the saturated solution of hydrochlorothiazide, suspending until forming a supersaturated condition to precipitate crystals, thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (g) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (f), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide; Method III: The method III comprises the following steps: (h) dissolving the telmisartan in an organic solvent to prepare a saturated solution of telmisartan; (i) adding a hydrochlorothiazide powder to the saturated solution of telmisartan, suspending until forming a supersaturated condition to precipitate crystals, thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (j) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (i), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide.

7. The preparation method for the cocrystal of telmisartan and hydrochlorothiazide according to claim 6, characterized in that, the organic solvent is one or more selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, isopentanol, acetonitrile, methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone, preferably methanol; In step (d), step (g) and step (j), the separating comprises: (d1) obtaining the cocrystal of telmisartan and hydrochlorothiazide by filtration; or (d2) obtaining the cocrystal of telmisartan and hydrochlorothiazide by centrifugation and filtration; or (d3) after separating the cocrystal of telmisartan and hydrochlorothiazide in the step (d1) or (d2), further evaporating to remove the liquid solution separated in the step (d1) or (d2), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide.

8. A pharmaceutical composition, said pharmaceutical composition comprises the cocrystal of telmisartan and hydrochlorothiazide of claim 1, and a pharmaceutically acceptable carrier.

9. Use of the cocrystal of telmisartan and hydrochlorothiazide of claim 1 or a pharmaceutical composition comprising the cocrystal of telmisartan and hydrochlorothiazide of claim 1 and a pharmaceutically acceptable carrier in preparation of a drug for the treatment of cardiovascular and cerebrovascular diseases.

10. A cocrystal of telmisartan and hydrochlorothiazide, characterized in that, in the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide, characteristic peaks exist at the 2 angle of about 5.560.2, 14.680.2, 15.470.2.

11. The cocrystal of telmisartan and hydrochlorothiazide according to claim 10, characterized in that, in the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide, further characteristic peaks exist at the 2 angle of about 9.960.2, 11.130.2, 17.720.2, 18.350.2, 19.430.2.

12. The cocrystal of telmisartan and hydrochlorothiazide according to claim 10, characterized in that, in the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide, further characteristic peaks exist at the 2 angle of about 7.410.2, 9.960.2, 11.130.2, 12.300.2, 17.720.2, 18.350.2, 19.430.2, 21.200.2, 22.150.2, 24.300.2, 24.810.2.

13. The cocrystal of telmisartan and hydrochlorothiazide according to claim 10, characterized in that, the X-ray powder diffraction pattern of the cocrystal of telmisartan and hydrochlorothiazide is shown substantially as the XRPD pattern of FIG. 1.

14. The cocrystal of telmisartan and hydrochlorothiazide according to claim 10, characterized in that, a characteristic melting peak at about 199.020.2 C. exists in the differential scanning calorimetry spectrum of the cocrystal of telmisartan and hydrochlorothiazide.

15. A preparation method for the cocrystal of telmisartan and hydrochlorothiazide of claim 10, the method is one of the following methods: Method I: The method I comprises the following steps: (a) dissolving the hydrochlorothiazide in an organic solvent to prepare a saturated solution of hydrochlorothiazide; (b) dissolving separately the telmisartan in the same organic solvent as that in step (a) to prepare a saturated solution of telmisartan; (c) mixing and stirring the saturated solution of hydrochlorothiazide in the step (a) and the saturated solution of telmisartan in the step (b), thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (d) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (c), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide; Method II: The method II comprises the following steps: (e) dissolving the hydrochlorothiazide in an organic solvent to prepare a saturated solution of hydrochlorothiazide; (f) adding a telmisartan powder to the saturated solution of hydrochlorothiazide, suspending until forming a supersaturated condition to precipitate crystals, thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (g) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (f), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide; Method III: The method III comprises the following steps: (h) dissolving the telmisartan in an organic solvent to prepare a saturated solution of telmisartan; (i) adding a hydrochlorothiazide powder to the saturated solution of telmisartan, suspending until forming a supersaturated condition to precipitate crystals, thereby forming the cocrystal of telmisartan and hydrochlorothiazide; (j) separating the cocrystal of telmisartan and hydrochlorothiazide formed in the step (i), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide.

16. The preparation method for the cocrystal of telmisartan and hydrochlorothiazide according to claim 15, characterized in that, the organic solvent is one or more selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, isopentanol, acetonitrile, methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone, preferably methanol; In step (d), step (g) and step (j), the separating comprises: (d1) obtaining the cocrystal of telmisartan and hydrochlorothiazide by filtration; or (d2) obtaining the cocrystal of telmisartan and hydrochlorothiazide by centrifugation and filtration; or (d3) after separating the cocrystal of telmisartan and hydrochlorothiazide in the step (d1) or (d2), further evaporating to remove the liquid solution separated in the step (d1) or (d2), so as to obtain the cocrystal of telmisartan and hydrochlorothiazide.

17. A pharmaceutical composition, said pharmaceutical composition comprises the cocrystal of telmisartan and hydrochlorothiazide of claim 10, and a pharmaceutically acceptable carrier.

18. Use of the cocrystal of telmisartan and hydrochlorothiazide of claim 10 or a pharmaceutical composition comprising the cocrystal of telmisartan and hydrochlorothiazide of claim 10 and a pharmaceutically acceptable carrier in preparation of a drug for the treatment of cardiovascular and cerebrovascular diseases.

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0052] FIG. 1 is the X-ray powder diffraction (XRPD) pattern of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0053] FIG. 2 is the one-dimensional proton nuclear magnetic resonance spectra (.sup.1H NMR) of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0054] FIG. 3 is the thermal gravimetric analysis (TG) curve of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0055] FIG. 4 is the differential scanning calorimetry (DSC) diagram of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0056] FIG. 5 is the infrared spectrum (IR) of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0057] FIG. 6 is the hydrochlorothiazide concentration-time curve in SD rat in vivo of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention;

[0058] FIG. 7 is the telmisartan concentration-time curve in SD rat in vivo of the cocrystal of telmisartan and hydrochlorothiazide of the Example 1 of the present invention.

DETAILED DESCRIPTION

[0059] Hereinafter, the present invention is further illustrated with reference to specific embodiments, but the present invention is not limited thereto.

[0060] The testing instruments and methods are as follows:

[0061] The instrument used for X-ray powder diffraction (XRPD) was Bruker D8 Advance diffractometer, using K ray (line with K1.5418 ) of Cu, with the voltage of 40 kV and current of 40 mA. The instrument is corrected for the peak position using the standard sample that comes with the instrument before using. The acquisition software is Diffrac Plus XRD Commander and the analysis software is MDI Jade 6.0. The samples were tested at room temperature, and the samples to be detected are put on the organic glass slide. The detailed test conditions are as follows: 2 angle range: 3 to 40, step size: 0.02; speed: 0.1 second/step. Unless otherwise specified, the samples were not ground before testing.

[0062] The data of proton nuclear magnetic resonance spectra (.sup.1H NMR) was collected using Mercury-Plus 400 from Varian company of USA. The sample was prepared using deuterated DMSO solution, and the solvent peak thereof was at 2.50 ppm. The analysis software is MestReNova.

[0063] The thermogravimetric analysis (TGA) data was collected using TG20F3 from NETZSCH Scientific Instrument Co., Ltd. of Germany, the control software of the instrument was NETZSCH-Proteus-6, and the analysis software was Proteus Analysis. The sample was heated from room temperature to 400 C. at a heating rate of 10 C./min under the protection of 50 mL/min of dry nitrogen, and the weight change of the sample during the heating process was recorded by the software in the same time.

[0064] The data of differential thermal analysis (DSC) was collected using DSC Q2000 differential scanning calorimeter of TA Instrument Company of USA. The control software of the instrument was Thermal Advantage, and the analysis software was Universal Analysis. The sample was heated from room temperature to 200 C. at a heating rate of 10 C./min under the protection of 50 mL/min of dry nitrogen, and the heat change of the sample during the heating process was recorded by the TA software in the same time.

[0065] The infrared analysis (IR) was performed at room temperature using the Nicolet-Magna FT-IR 750 infrared spectrometer from Nichols, USA. The detection wave number range is 4000-350 cm.sup.1.

[0066] The reagents such as methanol are of analytical grade and are provided by Sinopharm Chemical Reagent Co., Ltd. The reagents and solvents used are specially treated unless otherwise specified. The active pharmaceutical ingredients (APIs) of hydrochlorothiazide and telmisartan were purchased from Adamas Reagent Company, with a purity of more than 99%. All temperatures are presented in C. (degrees Centigrade), and the room temperature means 20 to 25 C.

EXAMPLE 1

[0067] Cocrystal of Telmisartan and Hydrochlorothiazide

[0068] At room temperature, a saturated solution of hydrochlorothiazide (29.7 g) was formed in 200 mL of methanol solution, and the supernatant was taken by filtration. Similarly, a saturated solution of telmisartan (51.5 g) was formed in 200 mL of methanol solution, and the supernatant was taken by filtration. The saturated solution of hydrochlorothiazide and the saturated solution of telmisartan were added to the beaker in an equal volume ratio, and were suspended until forming a supersaturated state. The resultant was centrifugated and filtrated, so as to obtain the cocrystal of telmisartan and hydrochlorothiazide (75.6 g).

[0069] The produced cocrystal of telmisartan and hydrochlorothiazide was characterized by X-ray powder diffraction (XRPD), proton nuclear magnetic resonance spectra (.sup.1H-NMR), thermal gravimetric analysis (TG), differential scanning calorimetry (DSC) and infrared (IR) spectra.

[0070] The analysis result of proton nuclear magnetic resonance spectra (.sup.1H-NMR) is shown in the FIG. 2, the result of the proton nuclear magnetic resonance spectra showed that the molar ratio of telmisartan and hydrochlorothiazide is 1:1. The two hydrogen atoms in the CH.sub.2 segment in the structure of hydrochlorothiazide molecular have a chemical shift of 4.7 ppm, and the two hydrogen atoms in the CH.sub.2 segment in the structure of telmisartan molecular have a chemical shift of 5.7 ppm. In the .sup.1H-NMR spectrum of the cocrystal, it can be seen that there are peaks at both chemical shifts, and the ratio of the integrated area of them is 1:1. Therefore, it can be determined that the molar ratio of two molecules in the cocrystal is 1:1.

[0071] The results of X-ray powder diffraction analysis are shown in FIG. 1; the results of thermogravimetric analysis are shown in FIG. 3; the results of differential scanning calorimetry analysis are shown in FIG. 4; and the results of infrared analysis are shown in FIG. 5.

EXAMPLE 2

[0072] Cocrystal of Telmisartan and Hydrochlorothiazide

[0073] At room temperature, hydrochlorothiazide (35.6 g) was dissolved in a methanol solution (200 mL) to form a saturated solution, and the supernatant was taken by filtration. A telmisartan powder (61.8 g) was added into the saturated solution of hydrochlorothiazide in methanol, the resultant was suspended until forming a supersaturated condition to precipitate crystals, so as to form cocrystal of hydrochlorothiazide and telmisartan. The resultant was centrifugated and filtrated, so as to obtain the cocrystal of hydrochlorothiazide and telmisartan (87.4 g).

EXAMPLE 3

[0074] Cocrystal of Hydrochlorothiazide and Telmisartan

[0075] At room temperature, telmisartan (66.9 g) was dissolved in a methanol solution (250 mL) to form a saturated solution, and the supernatant was taken by filtration. A hydrochlorothiazide powder (46.2 g) was added into the saturated solution of telmisartan in methanol, the resultant was suspended until forming a supersaturated condition to precipitate crystals, so as to form cocrystal of hydrochlorothiazide and telmisartan. The resultant was centrifugated and filtrated, so as to obtain the cocrystal of hydrochlorothiazide and telmisartan (100.2 g).

[0076] The produced cocrystal of hydrochlorothiazide and telmisartan in the Examples 2 and 3 were characterized by the solid chemical characterization method, such as X-ray powder diffraction (XRPD), proton nuclear magnetic resonance spectra (.sup.1H-NMR), thermal gravimetric analysis (TG), differential scanning calorimetry (DSC) and infrared (IR) spectra. The results thereof are substantially the same as those of the cocrystal of hydrochlorothiazide and telmisartan prepared in the Example 1.

EXPERIMENTAL EXAMPLE 1

[0077] Comparison of the maximum plasma concentration of cocrystal of hydrochlorothiazide and telmisartan in SD rats with that of hydrochlorothiazide or telmisartan itself.

[0078] The source of the test sample: cocrystal of hydrochlorothiazide and telmisartan prepared in Example 1, and hydrochlorothiazide and telmisartan APIs purchased from Adamas Reagent Company.

[0079] The experimental method is as follows:

[0080] The rats (females) were randomly divided into 4 groups with 6 rats per each group. The rats were fasted for 12 h but can drink freely before the test, and then were weighed.

[0081] Mode of Administration: Administrate with Suspension Agent

[0082] Administration dose: calculated according to the rat mass of 200 g for each one, formulated in a 0.5% sodium carboxymethylcellulose CMCNa aqueous solution.

TABLE-US-00001 Suspension Concen- Administration medium dose Administration tration dose (mg/kg) (mL) mass (mg/rat) (mg/mL) HCT 2.3 2 0.46 0.23 TEL 4 2 0.8 0.4 Cocrystal 6.3 2 1.26 0.63 Physical HCT 2.3 and 2 1.26 0.63 mixture TEL 4

[0083] The 4 groups were administrated intragastrically with HCT (hydrochlorothiazide), TEL (telmisartan), CC (co-crystal of telmisartan and hydrochlorothiazide) and PM (physical mixture of hydrochlorothiazide and telmisartan) respectively (approximately 2 mL). The rats were fed 3 h after the drug-administration. The 4 groups were administrated intragastrically with HCT, TEL, CC and PM respectively (approximately 2 mL). The rats were fed 3 h after the drug-administration. The blood collection site was orbital blood collection, blood collection time points: 0, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 18 h, 24 h. 200 L of blood (heparinized tube) were taken, which was centrifuged at 10,000 rpm for 5 min (at 10 C.). The plasma was separated, freezed at 20 C. in refrigerator, and used for blood concentration test after freezing.

[0084] Biological Sample Test Method:

[0085] Instrument: Shimadzu LC-MS 8030

[0086] MS Conditions:

TABLE-US-00002 Internal Hydrochlo- standard MS conditions rothiazide Telmisartan (tolbutamide) Ion pair detected in Q1 296/268.9 513.3/469.25 269.1/169.85 chamber/Ion pair detected in Q3 chamber Collision energy (eV) 18 22 15 Interface temperature ( C.) 400 DL pipe temperature ( C.) 250 Spraying gas flow 3 (mL/min) Heater component 400 temperature ( C.) Dry gas flow (mL/min) 15

Chromatographic Conditions:

[0087]

TABLE-US-00003 Packed column shim-pack GVP-ODS 5L * 2.0 (SHIMADZU) Chromatographic ACE column column Column temperature 40 C. Mobile phase A Acetonitrile Mobile phase C Aqueous solution containing 0.2% formic acid and 5 mmol of ammonium acetate Autosampler MeOHH.sub.2O 1:1 cleaning solution Flow Time rate A C Elution gradient (min) (mL/min) (%) (%) 0.01 0.2 60 40 5 0.2 STOP Total detection time 5 min Injection amount 10 L Each retention time HCT, TEL, IS 1.5 min, 2.3 min, 2.4 min

[0088] The results are shown in FIG. 6 and FIG. 7. It can be shown that under the condition that the hydrochlorothiazide, telmisartan and cocrystal thereof are administered with the same dose by intragastric administration, both the area under the curve (AUC) and the maximum concentration (Cmax) in the drug-time curve of the cocrystal are much higher than those of hydrochlorothiazide and telmisartan. It can be seen from the pharmacokinetic parameters of HCT that, the maximum concentration of the cocrystal sample is 1.24 times that of the separate administration group, and the AUC of the cocrystal sample is 1.65 times that of the separate administration group. It can be seen from the pharmacokinetic parameters of TEL that, the maximum concentration of the cocrystal sample is 5.64 times that of the separate administration group, and the AUC of the cocrystal sample is 5.0 times that of the separate administration group. Further, the AUC of cocrystal sample is also higher than the AUC of the normal mixed samples with the same dose. In particular, for telmisartan, the AUC of the cocrystal sample is considerably higher than the AUC of the normal mixed samples with the same dose. Thus it can be seen that the cocrystal samples have improved pharmacokinetic behavior of hydrochlorothiazide and telmisartan, especially, the cocrystal samples can significantly increase the content of telmisartan exposed in vivo.

EXPERIMENTAL EXAMPLE 2

[0089] According to the description in Stability Data Evaluation of ICH guidelines Q1E, a comparison of accelerated stability test (at 40 C.2 C., RH 755%) of cocrystal of hydrochlorothiazide and telmisartan obtained in Example 1 with that of telmisartan or hydrochlorothiazide itself was conducted respectively. The cocrystal of telmisartan and hydrochlorothiazide, telmisartan, and hydrochlorothiazide were double packaged using the polyethylene-sealed bag respectively, stood for 1, 2 or 3 months under the accelerated stability test conditions (at 40 C.2 C., RH 755%). Then the samples were taken and measured for the change of the content.

[0090] The Results of the Content Test in the Accelerated Test

TABLE-US-00004 Hydrochlo- Telmisartan Hydrochlo- time Telmisartan rothiazide in cocrystal rothiazide in (month) (%) (%) (%) cocrystal (%) 0 100 100 100 100 1 97.28 97.37 99.46 100.19 2 94.47 96.34 100.15 100.75 3 94.20 95.28 99.13 99.77

[0091] As can be seen from the results of accelerated tests, after 3 months, the contents of telmisartan and hydrochlorothiazide in the cocrystal were substantially maintained as the initial contents, but the telmisartan alone degraded to 94.20%, and hydrochlorothiazide alone degraded to 95.28%. It can be seen that, compared to the telmisartan and hydrochlorothiazide, the cocrystal of telmisartan and hydrochlorothiazide has better stability in the accelerated test, thus can effectively extend the shelf life of the drug.

[0092] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0093] The use of the terms a and an and the and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms comprising, having, including, and containing are to be construed as open-ended terms (i.e., meaning including, but not limited to,) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., such as) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0094] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.