Characterization of the cocrystal products formed by metoprolol and dabigatran bases with L-theanine

Abstract

Methods of making cocrystal compositions of metoprolol and dabigatran bases with enantiomers of theanine.

Claims

1. A method of making a cocrystal composition, comprising the steps of: providing a quantity of metoprolol; adding a quantity of a theanine enantiomer to the quantity of metoprolol to form a mixture comprising the quantity of metoprolol and the quantity of theanine enantiomer; wetting said mixture; and grinding said mixture, wherein the theanine enantiomer is selected from the group consisting of L-theanine, D-theanine and DL-theanine, and wherein the molar ratio of metoprolol to the theanine enantiomer is about 1:1.

2. The method of claim 1, wherein the quantity of metoprolol is 0.329 g or 1.231 mmol.

3. The method of claim 1, wherein the quantity of theanine enantiomer is 0.214 g or 1.228 mmol.

4. The method of claim 1, wherein the mixture is wetted with a solution comprising isopropanol.

5. The method of claim 1, wherein the wetting is conducted until a slurry is formed.

6. The method of claim 5, wherein the slurry is ground at the time of mixing.

7. The method of claim 1, wherein the grinding is performed until the mixture is dry.

8. The method of claim 4, wherein the solution comprises about 70% isopropanol.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The following is a brief description of the drawings, which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same.

(2) FIG. 1 depicts XRPD patterns of L-theanine (lower trace), metoprolol (middle trace), and the L-theanine/metoprolol cocrystal product (upper trace);

(3) FIG. 2 depicts fingerprint region FTIR spectra of L-theanine (lower trace), metoprolol (middle trace), and the L-theanine/metoprolol cocrystal product (upper trace);

(4) FIG. 3 depicts XRPD patterns of L-theanine (lower trace), dabigatran (middle trace), and the L-theanine/dabigatran cocrystal product (upper trace); and

(5) FIG. 4 depicts fingerprint region FTIR spectra of L-theanine (lower trace), dabigatran (middle trace), and the L-theanine/dabigatran cocrystal product (upper trace).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) Embodiments of the present invention employ theanine (5-N-ethyl glutamine), a non-protein amino acid found naturally in green tea leaves.

(7) Embodiments of the present invention include cocrystallization of metoprolol base with theanine (5-N-ethyl-glutamine).

(8) Embodiments of the present invention also include cocrystallization of dabigatran base with theanine (5-N-ethyl-glutamine).

(9) Embodiments of the present invention further include cocrystal compositions of the following medication groups with theanine (5-N-ethyl-glutamine): beta blockers, direct thrombin inhibitors.

(10) The present invention is directed to, among other things, cocrystal compositions of the following drug classes with theanine (5-N-ethyl-glutamine): beta blockers, direct thrombin inhibitors.

(11) Further, the theanine contained in compositions according to embodiments of the present invention may be of any of L-form, D-form, DL-form.

(12) According to embodiments of the present invention the L-, D-, DL-alpha amino acids of Theanine and their side-chain carbon homologues (nor, homo, and bishomologues) may have a functional R-group, where R1 may contain linear, cyclic, or branched alkyl groups and derivatives thereof; linear, cyclic, or branched alkenyl groups and derivatives thereof; and aromatic radicals and derivatives thereof. In embodiments of the present invention, the aromatic radicals may be aryl radicals.

(13) According to the embodiments of the present invention in addition to L-theanine, other analogues include D-Theanine, racemic theanine or D, L-theanine and its congeners including beta and reverse beta amino acid forms, shortened or nor-theanine (aspartic acid analogue), and the lengthened homo-theanines and their isomers. Further, gamma alkylamido analogues extend a full range of molecular property for drug cocrystals.

(14) According to the embodiments of the present invention the single enantiomers (S and R) and racemic forms (S, R-mixture) of the beta amino acids of theanine may have a functional R-group, where R1 may contain linear, cyclic, or branched alkyl groups and derivatives thereof; linear, cyclic, or branched alkenyl groups and derivatives thereof; and aromatic radicals and derivatives thereof. In embodiments of the present invention, the aromatic radicals may be aryl radicals.

(15) Embodiments of the present invention may include cocrystal compositions of drugs from the classes listed below and the enantiomers, L- and D-isomers, D, L-racemic mixture, S- and R-isomers, S, R-racemic mixtures, all rotamers, tautomers, salt forms, and hydrates of the alpha and beta amino acids of theanine in which the N-substituted functional R1-group [C4 or gamma-CH2-C(O)NR1] may contain linear, cyclic, or branched alkyl groups and derivatives thereof; linear, cyclic or branched alkenyl groups and derivatives thereof; and aromatic radicals (which may be aryl radicals) and derivatives thereof making up all the analogue forms of theanine: beta blockers, direct thrombin inhibitors.

(16) Derivatives prepared using metoprolol base/L-theanine cocrystal compositions according to embodiments of the present invention can be administered via intravenous, sublingual (including as an orally disintegrating tablet), and orally (including as a tablet).

(17) Derivatives prepared using dabigatran base/L-theanine cocrystal compositions according to embodiments of the present invention can be administered via sublingual, and orally.

(18) The pharmaceutical compositions according to embodiments of the present invention may be prepared as oral solids (tablets, oral disintegrating tablets, effervescent tablets, capsules), oral liquids, hard or soft gelatin capsules, quick dissolves, controlled release, modified release, extended release, slow release, sustained release, syrups, suspensions, granules, wafer (films), pellets, lozenges, powders, parenteral/injectable powders or granules that are pre-mixed or reconstituted.

(19) Cocrystals according to embodiments of the present invention may be used to improve one or more physical properties such as solubility, stability, and dissolution rate of the active pharmaceutical ingredient of a selected treatment or prevention.

(20) Next, the present invention will be described in further detail by means of examples, without intending to limit the scope of the present invention to these examples alone. The following are exemplary formulations with cocrystal compositions of the following medication groups with L-theanine in accordance with the present invention: beta blockers, direct thrombin inhibitors.

EXPERIMENTAL DETAILS, PREPARATION OF THE COCRYSTAL PRODUCTS

Example 1

(21) Preparation of the L-theanine/metoprolol cocrystal product was performed as follows: 0.329 g of metoprolol (1.231 mmol) and 0.214 g of L-theanine (1.228 mmol) were weighed directly into the bowl of an agate mortar, and wetted with 70% isopropanol to form a moderately thick slurry. The slurry was thoroughly ground at the time of mixing, and then periodically re-ground until the contents were dry.

Example 2

(22) Preparation of the L-theanine/dabigatran cocrystal product was performed as follows: 0.296 g of dabigatran (0.628 mmol) and 0.111 g of L-theanine (0.637 mmol) were weighed directly into the bowl of an agate mortar, and wetted with 70% isopropanol to form a moderately thick slurry. The slurry was thoroughly ground at the time of mixing, and then periodically re-ground until the contents were dry.

Instrumental Descriptions and Methodology

(23) X-ray powder diffraction (XRPD) patterns were obtained using a Rigaku MiniFlex powder diffraction system, equipped with a horizontal goniometer operating in the /2 mode. The X-ray source was nickel-filtered K emission of copper (1.54184 ). The sample was packed into the sample holder using a back-fill procedure, and were scanned over the range of 3.25 to 40 degrees 2 at a scan rate of 0.5 degrees 2/min. Using a data acquisition rate of 1 point per second, the scanning parameters equate to a step size of 0.0084 degrees 2. Calibration of the diffractometer system was effected using purified talc as a reference material.

(24) Fourier-transform infrared absorption (FTIR) spectra were obtained at a resolution of 4 cm.sup.1 using a Shimadzu model 8400S spectrometer, with each spectrum being obtained as the average of 40 individual spectra. The data were acquired using the attenuated total reflectance (ATR) sampling mode, where the samples were clamped against the ZnSe crystal of a PIKE MIRacle single reflection horizontal ATR sampling accessory. The intensity scale for all spectra was normalized so that the relative intensity of the most intense peak in the spectrum 100%.

(25) Measurements of differential scanning calorimetry (DSC) were obtained on a TA Instruments 2910 thermal analysis system. Samples of approximately 1-2 mg were accurately weighed into an aluminum DSC pan, and then covered with an aluminum lid that was inverted and pressed down so as to tightly contain the powder between the top and bottom aluminum faces of the lid and pan. All samples were heated at a rate of 10 C./min, with the dabigatran-related samples being heated over the temperature range of 25-300 C., while the metoprolol-related samples were heated over the temperature range of 25-125 C.

Results

The Theanine/Metoprolol System

(26) The XRPD patterns of L-theanine, metoprolol, and the L-theanine/metoprolol cocrystal product are shown in FIG. 1. Comparison of the diffraction patterns reveals that the XRPD pattern of the cocrystal product contains scattering peaks at angles of 19.85 and 24.85 degrees 2 that were not present in the XRPD patterns of the reactants. In addition, many of the peaks in the XRPD pattern of the cocrystal were found to be shifted to lower angles relative to their corresponding peaks in the XRPD patterns of the reactants. Since the XRPD pattern of the cocrystal product is different from the superimposed XRPD patterns of the reactants, this demonstrates that an authentic cocrystal is formed by L-theanine with metoprolol.

(27) The FTIR spectra in the fingerprint region (which is the most diagnostic region for critical study) of L-theanine, metoprolol, and the L-theanine/metoprolol cocrystal product are shown in FIG. 2. The most significant difference in the FTIR spectra is noted in the region around 1520 cm.sup.1, where the FTIR bands of the cocrystal product are substantially altered relative to the bands of the reactants in this same region, providing evidence for perturbation in the patterns of these vibrational motions. In addition, a number of other vibrational bands in the spectrum of the cocrystal product are shifted by several wavenumbers relative to the corresponding bands of the reactants.

(28) Finally, the DSC melting endotherm of the L-theanine/metoprolol cocrystal product was found to exhibit a peak at a temperature of 42 C., which is significantly lower than the peak observed for metoprolol itself (temperature of 53.5 C.).

The Theanine/Dabigatran System

(29) The XRPD patterns of L-theanine, dabigatran, and the L-theanine/dabigatran cocrystal product are shown in FIG. 3. Comparison of the diffraction patterns reveals that the XRPD pattern of the cocrystal product contains scattering peaks the region of 19.5 to 21 degrees 2 that were not present in the XRPD patterns of the reactants. In addition, several of the peaks in the XRPD pattern of the cocrystal were found to be shifted angles relative to their corresponding peaks in the XRPD patterns of the reactants. Since the XRPD pattern of the cocrystal product is different from the superimposed XRPD patterns of the reactants, this demonstrates that an authentic cocrystal is formed by L-theanine with dabigatran.

(30) The FTIR spectra in the fingerprint region (which is the most diagnostic region for critical study) of L-theanine, dabigatran, and the L-theanine/dabigatran cocrystal product are shown in FIG. 4. The most significant difference in the FTIR spectra is noted especially in the region of 1475 to 1600 cm.sup.1, where the FTIR bands of the cocrystal product are substantially altered relative to the bands of the reactants in this same region. In addition, a number of other vibrational bands in the spectrum of the cocrystal product are shifted by several wavenumbers relative to the corresponding bands of the reactants.

(31) The DSC melting endotherm of the L-theanine/dabigatran cocrystal product was found to exhibit a peak at a temperature of 218 C., which is significantly lower than the peak observed for dabigatran itself (temperature of 281.5 C.).

(32) Embodiments of the present invention include cocrystal compositions of L-Theanine combined with the drugs listed in the table below to treat the following conditions:

(33) TABLE-US-00002 Conditions Drug Arrhythmias in stable patients: ventricular tachycardia, Metoprolol atrial fibrillation with rapid ventricular response, Base atrial flutter, paroxysmal supra-ventricular tachycardia (except in patients with Wolff-Parkinson-White Syndrome), and multifocal atrial tachycardia (except in patients with COPD). Reduction of risk of stroke and systemic embolism in Dabigatran non-valvular atrial fibrillation, treatment of deep vein Base thrombosis and pulmonary embolism in patients who have been treated with a parenteral anticoagulant for days (patients who have been treated with a parenteral anticoagulant for 5-10 days), and reduction in the risk of recurrence of deep vein thrombosis and pulmonary embolism.

(34) While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.