ENHANCED BRAIN BIOAVAILABILITY OF GALANTAMINE BY SELECTED FORMULATIONS AND TRANSMUCOSAL ADMINISTRATION OF LIPOPHILIC PRODRUGS

Abstract

A method of treating a subject for a brain disease associated with cognitive impairment, including administering to a subject a chemical substance according to GLN-1062 or salt thereof:

##STR00001##

wherein the GLN-1062 or salt thereof is in a multi-layered tablet with a digestive acid resistant coating.

Claims

1. A method of treating a subject for a brain disease associated with cognitive impairment, comprising administering to the subject a therapeutically effective amount of GLN 1062 or salt thereof in a multi-layered tablet with a digestive acid resistant coating.

2. The method according to claim 1, wherein the digestive acid resistant coating comprises a poly(meth)acrylate coating.

3. The method according to claim 1, wherein the tablet comprises a tablet core, wherein said core comprises a therapeutically effective amount of GLN 1062 or salt thereof, microcrystalline cellulose (MCC), corn starch, hydroxypropyl methylcellulose (HPMC), and magnesium stearate.

4. The method according to claim 1, wherein the tablet comprises a tablet core, wherein said core comprises microcrystalline cellulose (MCC), and wherein the tablet comprises an active pharmaceutical ingredient layer (API layer) comprising a therapeutically effective amount of GLN 1062 or salt thereof and hydroxypropyl methylcellulose (HPMC).

5. The method according to claim 1, wherein GLN1062 is administered as a salt.

6. The method according to claim 4, wherein the salt comprises stoichiometric and/or non-stoichiometric salts and/or hydrates of GLN 1062, whereby the salt is described as: GLN 1062.Math.n HX.Math.m H2O; wherein n, m=0-5 and n and m can be the same or different, and HX=an acid.

7. The method according to claim 4, wherein the GLN1062 salt has a solubility in water of at least 10% weight per volume (w/v).

8. The method according to claim 4, wherein the GLN1062 salt is a gluconate salt, saccharate salt, maleate salt, or lactate salt.

9. The method according to claim 1, wherein GLN1062 or salt thereof is administered at a dosage of 1 to 100 mg one to three times daily.

10. The method according to claim 1, wherein the brain disease to be treated is selected from the group consisting of Alzheimer's disease, Parkinson's disease, dementia, schizophrenia, epilepsy, stroke, poliomyelitis, neuritis, myopathy, oxygen and nutrient deficiencies in the brain after hypoxia, anoxia, asphyxia, cardiac arrest, chronic fatigue syndrome, poisoning, anaesthesia, spinal cord disorders, central inflammatory disorders, postoperative delirium, subsyndromal postoperative delirium, neuropathic pain, abuse of alcohol and drugs, addictive alcohol and nicotine craving, and effects of radiotherapy.

11. A method of treating a subject for a brain disease associated with cognitive impairment, comprising administering to the subject a therapeutically effective amount of GLN 1062 or salt thereof via transmucosal administration, selected from intranasal, sublingual or buccal administration, in an emulsion or self-microemulsifying drug delivery (SMEDD) system.

12. The method according to claim 11, wherein the emulsion or SMEDD comprises additionally one or more surfactants, oils and co-surfactants and is prepared under stirring and/or ultrasound.

13. The method according to claim 11, wherein the emulsion or SMEDD comprises additionally glyceryl caprylate, polyethyleneglycol, propyleneglycol and/or diethyleneglycolemonoethylether.

14. The method according to claim 11, wherein GLN1062 is administered as a salt.

15. The method according to claim 14, wherein the salt comprises stoichiometric and/or non-stoichiometric salts and/or hydrates of GLN 1062, whereby the salt is described as: GLN 1062.Math.n HX.Math.m H2O; wherein n, m=0-5 and n and m can be the same or different, and HX=an acid.

16. The method according to claim 14, wherein the GLN1062 salt has a solubility in water of at least 10% weight per volume (w/v).

17. The method according to claim 14, wherein the GLN1062 salt is a gluconate salt, saccharate salt, maleate salt, or lactate salt.

18. The method according to claim 11, wherein GLN1062 or salt thereof is administered at a dosage of 1 to 100 mg one to three times daily.

19. The method according to claim 11, wherein the brain disease to be treated is selected from the group consisting of Alzheimer's disease, Parkinson's disease, dementia, schizophrenia, epilepsy, stroke, poliomyelitis, neuritis, myopathy, oxygen and nutrient deficiencies in the brain after hypoxia, anoxia, asphyxia, cardiac arrest, chronic fatigue syndrome, poisoning, anaesthesia, spinal cord disorders, central inflammatory disorders, postoperative delirium, subsyndromal postoperative delirium, neuropathic pain, abuse of alcohol and drugs, addictive alcohol and nicotine craving, and effects of radiotherapy.

20. A method of treating a subject for a brain disease associated with cognitive impairment, comprising administering to the subject a therapeutically effective amount of GLN 1062 or salt thereof via transmucosal administration, selected from intranasal, sublingual or buccal administration, in a micronized powder formulation.

21. The method according to claim 11, wherein the micronized powder formulation comprises nanocrystals of GLN 1062 and polymeric micro-particles to which GLN 1062 is adsorbed.

22. The method according to claim 11, wherein the micronized powder formulation is obtained by co-precipitation of polymer and GLN 1062, by pearl milling and homogenization in water.

23. The method according to claim 11, wherein GLN1062 is administered as a base.

24. The method according to claim 1, wherein GLN1062 or salt thereof is administered at a dosage of 1 to 100 mg one to three times daily.

25. The method according to claim 1, wherein the brain disease to be treated is selected from the group consisting of Alzheimer's disease, Parkinson's disease, dementia, schizophrenia, epilepsy, stroke, poliomyelitis, neuritis, myopathy, oxygen and nutrient deficiencies in the brain after hypoxia, anoxia, asphyxia, cardiac arrest, chronic fatigue syndrome, poisoning, anaesthesia, spinal cord disorders, central inflammatory disorders, postoperative delirium, subsyndronal postoperative delirium, neuropathic pain, abuse of alcohol and drugs, addictive alcohol and nicotine craving, and effects of radiotherapy.

Description

FIGURES

[0109] The invention is further described by the figures. These are not intended to limit the scope of the invention.

[0110] FIG. 1: Powder diffraction diagram of Memogain gluconate obtained using dioxane.

[0111] FIG. 2: Adsorption/desorption isotherm of Memogain gluconate monohydrate.

[0112] FIG. 3: Weight loss on heating of Memogain gluconate monohydrate.

[0113] FIG. 4: Differential scanning calorimetry (DSC) the wet cake of Memogain gluconate.

[0114] FIG. 5: Powder diffraction diagram of Memogain gluconate obtained using ethanol.

[0115] FIG. 6: Experimental brain-to-blood concentration ratios for galantamine and several pro-galantamines.

[0116] FIG. 7: Intranasal Memogain is more potent than galantamine Mice were challenged with scopolamine and dosed with increasing concentrations of oral galantamine and intranasal Memogain before performance evaluation in the mouse T-maze model.

[0117] FIG. 8: The first-pass effect of Gln-1062 was evaluated after intravenous and intraportal dosing of 3 mg/kg in Wistar rats.

[0118] FIG. 9: Intranasal administration of Memogain leads to low amounts of liberated galantamine in plasma.

[0119] FIG. 10: Memogain produces fewer gastro-intestinal side effects than galantamine.

[0120] FIG. 11: Lower toxicity of Memogain is due to the lower steady-state plasma levels of galantamine resulting from enzymatic cleavage of the pro-drug.

[0121] FIG. 12: The pharmacokinetic profiles of Memogain and galantamine in female Wistar rat after intra-nasal application of 5% Memogain salt in 10% NEP in water, 10 μL per nostril, a total of 20 μL containing 1 mg are shown below.

[0122] FIG. 13: Mice were injected with 3 mg/kg i.v. of either Memogain or galantamine. The data demonstrate that galantamine does not penetrate the brain well compared to Memogain.

[0123] FIG. 14: Intranasal administration of Memogain in a Rat PK study. 5 mg/kg intranasal (i.n.) Memogain dosing was performed under GLP-like conditions.

EXAMPLES

[0124] The invention is further described by the following examples. The examples are intended to further describe the invention by way of practical example and do not represent a limiting description of the invention.

Example 1. High-Concentration Aqueous Salt Solutions and Organic Solvent Solutions of Pro-Drugs

[0125] For one of the drugs considered herein, galantamine, intranasal formulations were previously developed on the basis of aqueous solutions of highly soluble salts (WO 2005/102275 A1; Leonhard A K et al. (2005) Development of a novel high-concentration galantamine formulation sutable for intranasal delivery. J Pharmaceut Sciences 94: 1736-1746; Leonard A K et al. (2007) In vitro formulation optimization of intranasal galantamine leading to enhanced bioavailability and reduced emetic response in vivo. Int J

[0126] Pharmaceutics 335: 138-146).

[0127] While the reported galantamine salt formulations allowed administration of galantamine at similarly high doses as is recommended for oral administration of tablets, intranasal administration did not improve the brain/blood concentration ratio of galantamine, as the physicochemical properties of the drug and hence penetration through the BBB did not change by this approach. In contrast, when the same salt formulations are formed from the pro-drugs disclosed herein, a large increase in lipophilicity (log P) is achieved, concomitantly with much better penetration through the BBB. This can be seen in FIG. 1.

[0128] The combination of salt formation with prodrug properties, in particularly with regard to GLN 1062, shows a synergistic effect of improved absorption through the mucosal membrane and direct uptake to the brain, thereby enabling enhanced delivery to the site of action.

[0129] The blood-brain barrier penetration achieved by the various salts of the invention—in comparison to both the galantamine base compound, but also in comparison to oral administration of the derivatives themselves, —is increased in an unexpected and significant manner.

[0130] 1.1. Salt of Memogain with Acetic Acid: (General Procedure A):

[0131] To the solution of Memogain (502 mg, 1.28 mmol in 2 ml 96% ethanol) acetic acid (463 mg, 7.71 mmol) was added and the resultant solution was stirred for some time and left overnight for salt formation resulting in the precipitation of the acetate salt. The yield was improved by addition of diethyl ether and the precipitate was filtered and washed with 96% ethanol. The precipitate was dried in a desiccator at r.t. at 40 mbar for 20 h. Results: colorless solid (Hygroscopic). Yield: 62%, m.p.: 89.3-91.2° C., HPLC>95%. Elemental analysis: Calcd. for C.sub.24H.sub.25NO.sub.4*1.5 CH.sub.3COOH C:71.24, H: 6.46, N: 3.32 Found C: 71.36, H: 6.17, N: 3.43.

[0132] Several other crystal forms containing 1-2 molar equivalents of acetic acid were obtained in a similar manner by changing the relative amounts of Memogain and acid as well as the precipitation method.

[0133] 1.2. Salt of Memogain with Lactic Acid: (General Procedure B):

[0134] To the solution of 2.5 g Memogain (6.4 mmol) in methanol (4 ml) a solution of 95% racemic lactic acid (7.85 mmol) in methanol (2 ml) was added at 40-50° C. and stirred for 20 min. The solvent was evaporated and the resulting residue was dried first using a rotavap for 2 hrs at 9 mbar and at 50−60° C. followed by overnight drying at 40 mbar at r.t. resulting in a solid light yellow foam that was highly hygroscopic. Yield: 98.92%, m.p.: 62.9-64.1° C., Elemental analysis: Calcd. for C.sub.24H.sub.25NO.sub.4*1.1 C.sub.3H.sub.6O.sub.3 C: 66.84, H: 6.49, N: 2.86. Found: C: 66.69, H: 6.45, N: 2.80 HPLC purity>97%.

[0135] In a similar manner the corresponding salt with (+)-lactic acid was obtained: Calcd. for C.sub.24H.sub.25NO.sub.4*1.5 C.sub.3H.sub.6O.sub.3 C: 65.01, H: 6.51, N: 2.66. Found: C: 64.91, H: 6.28, N: 2.70.

[0136] 1.3. Salt of Memogain with Citric Acid:

[0137] Using general procedure B but dry ethanol as solvent the citrate was obtained in 91.0% yield as sticky solid that turned into a colorless solid after trituration using dry diethyl ether followed by high vacuum evaporation with m.p.: 117.5-119° C. Elemental analysis: Calcd for C: 73.64, H: 6.44, N: 3.58 Found C: 59.61, H: 5.93, N:2.26. HPLC>97%

[0138] 1.4. Salt of Memogain with Saccharic Acid (General Procedure C):

[0139] To a solution of Memogain (1120 mg) in 96% ethanol (4 ml) was added a solution of saccharolactone (200-604 mg) in 96% ethanol (3 ml) at 60°. The hot solution was immediately diluted with ethyl acetate resulting in the formation of a colorless precipitate that was filtered after cooling to 5° for 2 hrs, washed with ethyl acetate and dried at 40 mbar for 20 hrs at r.t. to give a 83.7% yield of the saccharic acid salt as colorless solid with m.p.: 132-134° C. and HPLC-purity of >97%. Elemental analysis: Calcd. for C.sub.24H.sub.25NO.sub.4*C.sub.6H.sub.10O.sub.8 C: 59.89, H: 5.86, N: 2.33. Found: C: 60.10, H: 5.61, N: 2.37. The lactone of saccharic acid is hydrolyzed with water present under these conditions resulting in the salt described.

##STR00043##

[0140] 1.5. Salt of Memogain with Gluconic Acid:

[0141] Following in general procedure C starting from Memogain (150 mg, 0.38 mmol) but using dioxane as solvent and a solution of D-gluconic acid delta-lactone (68.2 mg, 0.38 mmol) in dioxane containing water (13 mg, 0.76 mmol) and stirring at 50-60° C. for 30 min. until a clear solution was obtained followed by addition of dry diethyl ether (10 ml) to the cooled solution resulted in a colorless precipitate that was filtered, washed with diethyl ether and dried to obtain 170 mg (75.6%) of the salt as colorless, crystalline solid. m.p.:159.3-159.4° C. HPLC purity>98% Elemental analysis: Calcd. for C.sub.24H.sub.25NO.sub.4*1.5 C.sub.6H.sub.12O.sub.7 C: 57.80, H: 6.32, N: 2.04. Found: C: 58.22, H: 5.98, N: 2.28. The powder diffraction diagram of this salt is shown in FIG. 1.

[0142] From a similar experiment on twice the scale but without adding diethyl ether for precipitation spontaneous crystals were formed on standing at r.t. for 3 days that were filtered, washed with dioxane and dried to obtain 145 mg (32%) of the 1:1 salt as colorless crystals with m.p. 173.3-173.4° C. Calcd. for C.sub.24H.sub.25NO.sub.4*C.sub.6H.sub.12O.sub.7 C: 61.32, H: 6.35, N: 2.38. Found: C: 61.65, H: 6.27, N: 2.64. Microtitration of this salt verified the stochiometry calculated from the elemental analysis.

[0143] Under similar conditions but prolonged drying other salt-forms containing 0-2 equival. of water in the crystal were obtained. It is known that D-gluconic acid delta-lactone is hydrolyzed to gluconic acid by water.

[0144] In an alternative procedure ethanol was used as a solvent. Thus Memogain (9.4 g, 24 mmol) in 96% ethanol) was added to a solution of D-gluconic acid delta-lactone (6416 mg, 36 mmol) in 96% ethanol (10 ml) and heated to 50-60° C. for 30 min. until a clear solution was obtained that was kept at r.t. for 2 days with the formation of a colorless precipitate that was filtered, washed with dry ethanol (2×20 ml) and isopropanol (60 lm) and dried at 40 mbar at r.t. for 20 hr to obtain 7.91 g (84.2%) of the product as colorless crystalline solid m.p.: 122-126° C., HPLC purity>98%. Elemental analysis: Calcd. for C.sub.24H.sub.25NO.sub.4*C.sub.6H.sub.12O.sub.7*H.sub.2O C: 59.50, H: 6.49, N: 2.31. Found: C: 59.60, H: 6.59, N: 2.32.

[0145] This salt was used to obtain the adsorption/desorption isotherm of water (FIG. 2) as well as the weight loss on heating (FIG. 3). Furthermore by differential scanning calorimetry (DSC) of the wet cake of Memogain gluconate it was determined, that drying takes place between 53 and 87° C. and melting around 123° C. (FIG. 4). The powder diffraction diagram of this salt is shown in FIG. 5

[0146] .sup.1HNMR (200 MHz, D2O): δ 7.35-7.46 (d, 2H), 7.09-6.94 (t, 1H), 6.92-6.80 (t, 2H), 6.59-6.36 (m, 2H), 6.14-6.00 (d, 1H), 5.85-5.72 (m, 1H), 5.16-5.07 (s, 1H), 4.48-4.31 (m, 4H), 4.13-3.84 (m, 5H), 3.73-3.53 (m, 6H), 3.53-3.39 (m, 5H), 2.76-2.58 (s, 3H) 2.39-2.21 (d, 1H), 2.06-1.69 (m, 3H)

[0147] .sup.13CNMR (50 MHz, D2O): δ 178.39 (s, 1C), 167.03 (s, 1C), 146.09 (s, 1C), 145.11 (s, 1C), 133.09 (s, 1C), 131.57 (s, 1C), 129.26 (s, 1C), 128.04 (s, 1C), 123.75 (s, 1C), 123.40 (s, 1C), 119.02 (s, 1C), 118.74 (s, 1C) 118.67 (s, 1C), 112.05 (s, 1C), 85.82 (s, 1C), 73.93 (s, 1C), 73.52 (s, 1C), 72.46 (s, 1C), 71.07 (s, 1C), 70.81 (s, 1C), 64.23 (s, 1C), 62.54 (s, 1C), 58.51 (s, 1C), 55.52 (s, 1C), 53.98 (s, 1C), 46.50 (s, 1C), 40.96 (s, 1C) 40.82 (s, 1C), 32.07 (s, 1C), 26.83 (s, 1C).

[0148] Using the general procedures A, B and C the following salts were prepared on a 0.5 to 10 mmol scale in a similar manner and un-optimized yields of 42-91% were obtained. For those salts that were obtained in a crystalline state the melting points are indicated. Salts that showed solubility in water higher than 10% or even 20% were investigated further.

[0149] In addition to this list, pharmaceutically acceptable salts as described in table 1 of the book Pharmaceutical Salts, Properties, Selection and Uses, Stahl, P. H. and Wermuth, C. G., eds., VHCA Verlag 2002, can be used.

[0150] 1.6. Solubility Test

[0151] 10 mg of the corresponding salt and 100 microliters of water were sonicated for 5 min at r.t. The resulting solution or suspension was centrifuged for 3 min. and filtered using a filter tip. 10 microliters of the filtrate was transferred in a volumetric flask and diluted to 10.0 ml with water to obtain the sample solution. 20 microliters of this sample solution was injected for HPLC and the amount of Memogain quantified using a Merck Chromolith RP18 column and a gradient of 5% to 60% acetonitrile and water, both solvents containing 0.1% formic acid, injection volume: 20 microliters.

[0152] The Memogain salts of acetic acid, maleic acid, lactic acid (lactate salt), citric acid, saccharic acid (saccharate salt) and gluconic acid (gluconate salt) all showed solubility at above 10% in water.

[0153] The lactate, gluconate, maleate and saccharate salts of Memogain showed solubility above 10% weight per volume (w/v), sometimes forming meta-stable salts at 20% concentration in solution. The gluconate salt showed solubility at 40% weight per volume (w/v) and the saccharate salt at 70% weight per volume (w/v).

TABLE-US-00003 TABLE 3 Additional Memogain Salts Acid m.p.(° C.) Ascorbic acid 110-131 (decomp.) Arabic acid 213 (decomp.) Adipic acid DL-Mandelic acid D-Glucoheptono-1,4-lactone 147 (decomp.) Formic acid 146-147 Fumaric acid Galactaric acid 143-144 D-(+)-Galacturonic acid 148-151 Glucuronic acid 145-146 Glycolic acid  97-103 Hydrobromic acid 221-222 Hydroxy citric acid Hydrochloric acid Isethionic acid 191-195 Maleic acid L-(−)-Malic acid 107-108 Malonic acid Nicotinic acid 117-118 Phosphoric acid Succinic acid Sulfuric acid 172-173 L-(+)-Tartaric acid 185-186 D-(−)tartaric acid 212-213 Meso tartaric acid 107-109

[0154] Particularly preferred are quaternary nitrogen salts (otherwise termed quaternary ammonium salts) of acetic acid, maleic acid, lactic acid (lactate salt), citric acid, saccharic acid (saccharate salt) and gluconic acid (gluconate salt).

[0155] These acids form salts with Memogain and other galantamine pro-drug nitrogen bases having solubility of up to 70% at neutral pH in water. While high-concentration of the gluconate salt in aqueous solution is metastable and is later converted to less soluble stable salt forms, the fully dissolved homogenous solutions can be recovered by warming the aqueous mixtures to >50° C. until precipitations have disappeared. These metastable homogenous solutions remain stable for hours and days, provided that precautions are taken to reduce or avoid precipitation seeding. Appropriate documentation of the dissolution procedure to form such metastable (hypercritical) solutions renders these solutions suitable drug product formulations for use by patients and medical personal. A short warming, for example for 5 minutes by hand, before administration allows optimal administration of such metastable solutions.

[0156] As sustained release aqueous formulations of the pro-drugs discussed here, we have dissolved in water a powder of the natural biopolymer chitosan, and mixed it with Memogain base or hydrogen salt so as to achieve formulations for intranasal delivery of 5% (w/v) or more (Illium L et al. (2002). Intranasal delivery of morphine. J Pharmacol Exp Therap 301: 391-400). The method of application described in Illium et al is also suitable for use with the chemical substances of the present invention.

[0157] Sustained release formulations of Memogain salts comprising chitosan also proved effective when applied in solid form in oral sublingual or buccal administration, and showed unexpectedly fast initial absorption with long release times.

[0158] The preferred salts of the present invention represent preferred embodiments that exhibit unexpectedly surprising and advantageous effects in comparison to what was disclosed in the prior art or what could have been expected by a skilled person in light of the prior art.

[0159] The solubility of the particular preferred salts is unexpectedly good, allowing a higher concentration of medicament in the pharmaceutical composition (i.e. in the form of a solution in a particularly preferred embodiment for intranasal administration, but also buccal or sub-lingual application). This is of great importance in light of the requirements mentioned above for compounds that are suitable for intranasal, sublingual or buccal administration. Due to the limited size of the nasal cavity the required concentration of the active substance in solution is high. This means that salts needed to be found, which could be very soluble and therefore provided at a high concentration. This is surprisingly the case for the salts mentioned herein, preferably for acetic acid (acetate salt), lactic acid (lactate salt), citric acid, saccharic acid (saccharate salt) and gluconic acid (gluconate salt).

Example 2. Emulsions and Selfmicroemulsifying Drug Delivery Systems (SMEDDs)

[0160] Emulsions and SMEDDs are established means of brain delivery systems (Botner S, Sintov A C (2011) Intranasal delivery of two benzodiazepines, Midazolam and Diazepam, by a microemulsion system. Pharmacol Pharmacie 2:180-188). In the present application they were produced by mixing the pro-drug under investigation, as nitrogen base or as hydrogen salt, with various organic solvents or by mixing with suitable surfactants, oils and co-surfactants (all recognized as safe; GRAS) under stirring and/or ultrasound until a clear solution was achieved. In particular, we avoided using alcohols or other irritant chemicals in the formulations so as to avoid any irritability of the nasal or buccal mucosa. Typical components of such microemulsions were Labrasol, N-ethyl-2-pyrrolidone (NEP), glyceryl oleate, PEG, propylene glycol, Transcutol, and suitable oils, such as palmitate. We achieved drug solubilities of the order of 10% (w/w), or more, with a maximal water solubilization capacity of approx. 50% (the lower the water content, the higher oil concentrations could be achieved, and the higher the solubility of nitrogen base). The highest solubilities of pro-drug nitrogen bases or salts were obtained at water concentrations around 20% in the microemulsions.

[0161] Preferred embodiments of the self-microemulsifying drug delivery (SMEDD) formulation, preferably for Memogain maleate, relate to the following: Used Materials:

[0162] Memogain maleate (No. 022563-A-1-1, GALANTOS Pharma GmbH, Germany)

[0163] Capmul MCM (Lot: 080726-7, BERENTZ-ABITEC CORP., USA) (glyceryl caprylate/caprate; Pharm. Eur.)

[0164] PEG 300/400 (Lot: 1349048-41108320, FLUKA, Vienna, Austria) (polyethyleneglycol; Pharm. Eur.)

[0165] Propyleneglycol (Lot: S44324-108, SIGMA, Vienna, Austria) (propyleneglycol; Pharm. Eur)

[0166] Transcutol (Lot: 18703CE, SIGMA, Vienna, Austria) (diethyleneglycolemonoethylether; Pharm. Eur.)

[0167] Preparation of a 10% Memogain Maleate SMEDD Formulation (1 L):

[0168] As the first step, 100 g of Memogain maleate are weighted into an appropriate steel tank.

[0169] In the following the solubilizers and fatty oils are added one after each other:

[0170] 170 ml of Capmul MCM

[0171] 500 ml PEG 300

[0172] 220 ml Propyleneglycol

[0173] 110 ml Transcutol

[0174] Finally the SMEDD formulation is treated with ultrasound until the mixture becomes a clear solution.

[0175] The Memogain base and salt emulsion and SMEDD formulations demonstrate reduced local irritation of the mucosal surface upon application. Furthermore, the bitter taste of the prodrug is effectively masked through the various lipid and PEG components and no analgesic effect on the transmucosal surface was evident.

Example 3. Micronized Powder Formulations and Nano-Suspensions of Pro-Drug Crystals

[0176] Other suitable formulations for transmucosal delivery are pro-drug nano-crystals and polymeric micro-particles to which pro-drugs are adsorbed. In both cases, the more lipophilic pro-drug bases were used. The formulations were obtained by co-precipitation of polymer and pro-drug, by pearl milling and homogenization in water, or as nano-suspensions of pro-drugs that are lipid conjugates. Such methods are known to one skilled in the art and could be applied with the chemical substances and methods of administration of the present invention.

[0177] The micronized powder compositions of GLN 1062 or salts thereof enable fast absorption and a reduction in the bitter taste of the compound, compared to when applied as an aqueous solution.

Example 4. Memogain-Formulations

[0178] Solubility of Memogain

[0179] Free Base in Water: 26 pg/ml (66 μM)

[0180] Maleate in Water: 7.5 mg/ml (15 mM)

[0181] Maleate in 0.9% NaCl: 0.6 mg/ml (1.5 mM)

[0182] Free Base in Cyclodextrin-Vehicle.sup.1): 8.9 mg/ml (23 mM) .sup.1) 15% (109 mM) Hydroxypropyl-β-cyclodextrin, 96 mM NaCl

[0183] Maleate in Cyclodextrin-Vehicle.sup.1): 21 mg/ml (41 mM)

TABLE-US-00004 TABLE 4 Formulations Name GEA1 Type Sublingual Tablet API Memogain maleate API/Tablet  1 mg Tablet mass 20 mg Carrier Lactose monohydrate Ethanol .sup.1) Corn starch Povidon K30 (polyvinylpyrrolidone (PVP)) Magnesium stearate Name GEA2 Type Sublingual Tablet API Memogain maleate API/Tablet  2 mg Tablet mass 50 mg Carrier Mannitol Explotab (sodium starch glycolate) Croscarmellose Ascorbic acid Magnesium stearate Orange flavour Name Evonik 1 Type Multi-layered Pellets (ca. 1 mm) with digestive acid resistant coating API Memogain maleate API-amount 1% Pellet core Cellet 700 (MCC) API-layer Memogain maleate and Methocel E5 (HPMC) Subcoating Methocel E5 (HPMC) Coating Eudragit FS30D, Talc, Triethylcitrate Layer thickness Approx. 30 μm bei 15% Coating; Eudragit: also Pellets with 5% and 10 were manufactured. Name Evonik 2 Type Multi-layered Tablets (appr. 9 mg) with digestive acid resistant coating API Memogain maleate API-amount 2 mg Pellet core Memogain maleat, Avicel PH 102 (MCC), corn starch, Methocel E5 (HPMC), Magnesium stearate Subcoating Methocel E5 (HPMC) Coating Eudragit FS30D, Talc, Triethylcitrate Layer thickness appr. 90 μm bei 15% coating; Eudragit: also Pellets with 5% and 10% were manufactured. .sup.1) removed during production

[0184] The sub-lingual tablets and multi-layered formulations of the present invention show surprisingly good adsorption properties, enabling quick uptake and reduced flavour bitterness, in addition to reduced analgesic effects in the mouth of the patient. The fast adsorption of chemical substance enables a reduced risk of swallowing; thereby ensuring the administration occurs transmucosally through the oral mucous membrane, avoiding unwanted degradation of the prodrug.

Example 5. Interaction with Carrier Substance and Eudragit (Poly(Meth)Acrylate)

[0185] Experiment 1: a small amount (0.1 mg) of Memogain maleate in 1 ml HBSS-Puffer, pH 7.4 was incubated with various carriers at 37° C. 2.5 h. The amount of free (not bound to the particle of the carrier substance) of Memogain was then measured by HPLC. Typical amounts of carrier substance were applied and shown in Table 5.

TABLE-US-00005 TABLE 5 Non-absorbed Memogain Nr. Substance mg carrier (% of control) control none 0 100 1 Lactose 10 105 2 MCC 10 100 3 HPMC 1 105 4 Corn starch 5 100 5 Eudragit L100 2 21 6 Eudragit FS30D 1.8 7 7 Talc 2 94 8 Mg Stearate 0.1 101 9 Mg Stearate + Tw20 0.1 plus 0.1% 103 Tw20 10 Aerosil (SiO.sub.2) 1 89 11 Emcompress 10 101 (CaHPO.sub.4) 12 Explotab 2 99 13 Triethylcitrat 0.2 101

[0186] Result: Eudragit L100 and Eudragit FS30D adsorb Memogain.

[0187] Experiment 2: a fixed amount of Eudragit (0.5 mg/ml) was incubated with various amounts of Memogainmaleate for 2 h in a saline solution (HBSS). The amount of free (not bound to the particle of the carrier substance) of Memogain was then measured by HPLC. In parallel the solubility of the Eudragit amount alone in the salt solution was analysed.

[0188] Result: L100 is completely soluble in the provided concentration, FS30D forms a cloudly solution. FS30D binds to Memogain over the entire tested concentration range. As of 0.25 mg/ml Memogain forms a precipitate with L100, which can be re-solubilised by the addition of 6% Cycldodextrin (HPCD).

Example 6. In Vitro Studies of Permeation Behavior, Pre-Systemic Metabolism and Stability

[0189] Permeation behavior of pro-drug formulations was tested using tissue samples of 3-4 cm.sup.2 freshly excised porcine nasal or buccal mucosa inserted in an Ussing-type chamber displaying a permeation area of 0.64 cm.sup.2 and a volume of 1 ml on both sides. The apical side of the tissue was facing the donor compartment. One ml of pre-warmed (37° C.) permeation medium was added to the donor and acceptor chamber. The temperature within the chambers was maintained at 37° C. throughout the entire experiment. After a pre-incubation time of 15 min the permeation medium in the donor chamber was substituted by a 1% solution of the pro-drug formulation under investigation. Every 30 min aliquots of 100 μl were withdrawn from the acceptor compartment and immediately replaced by 100 μl of fresh pre-warmed permeation medium over a time period of 180 min. The concentration of compounds in the collected aliquots was determined via HPLC. Corrections were made for previously removed samples. Apparent permeability coefficients (Papp) were calculated. Control samples were withdrawn from the donor compartment after 180 min and analyzed to investigate the stability of the compound in the formulation under investigation.

[0190] During the above described permeation experiments, 10 μl aliquots were withdrawn from the donor compartment at time points 0, 60, 120 and 180 min. These aliquots were analyzed by HPLC to determine the degree of pre-systemic metabolism over time.

[0191] Using these methods, aqueous solutions of pro-drug salts, and solutions of pro-drug bases in organic solvents, co-solvents and surfactants were tested as to their solubility, their permeation coefficient, and their pre-systemic metabolism and stability. The formulations further studied had solubilities of at least 10% (m/v), and permeation coefficients of pro-drugs of Papp>1.10-6 cm/s. Within the time periods tested, there was no significant pre-systemic metabolism of pro-drugs in both porcine mucosa preparations.

Example 7. Pharmacokinetics

[0192] The pharmacokinetics of pro-drugs and parent drugs after transmucosal delivery in the nasal or buccal cavity were tested in Wistar rats. These data confirmed rapid (within minutes) uptake into blood and brain of the pro-drugs under investigation, bioavailabilites in the brain of pro-drugs similar to those produced by intravenous injections, and much higher BBRC, as compared to oral delivery as tablet of the related parent drug.

[0193] Because redistribution of parent drug via BBB to the circulation, after enzymatic production from pro-drug in the brain, is very fast indeed, pharmacokinetic studies do not suffice to exactly determine the momentary concentrations of parent drug in the brain. We therefore used pharmacodynamics studies to determine the effective concentrations of parent drug in suitable experimental conditions, such as the reversal of scopolamine-induced temporary amnesia in the T-maze cognitive paradigm studied in mice. These studies confirmed that several fold higher (up to 20 fold) BBRC of parent drug (and related effectiveness in cognitive enhancement) can be achieved by transmucosal delivery of pro-drug formulations via the nasal or buccal cavity.

[0194] Experiments directly comparing potency and reduced GI side effects of Memogain between oral and transmucosal (nasal) administration also demonstrate that intranasally administered Memogain exhibits surprisingly beneficial properties in comparison to orally administered Memogain.

[0195] Pharmacokinetc studies were carried out using intranasal and sublingual administration of the Memogain maleate salt.

[0196] Intranasal Report:

[0197] This experimental plan describes the blood and brain pharmacokinetic profiles of the pro-galantamine Memogain maleate and galantamine in female wistar rat following intra-nasal application of the Memogain maleate and galantamine Hydrobromide in various formulations. [0198] a. 5% galantamine in water, 10 μL per nostril, a total of 20 μL containing 1 mg 5% [0199] b. Memogain salt in 10% NEP in water, 10 μL per nostril, a total of 20 μL containing 1 mg [0200] c. 5% Memogain salt in an emulsion, 10 μL per nostril, a total of 20 μL containing 1 mg [0201] d. 20% Memogain salt in an emulsion, 10 μL per nostril, a total of 20 μL containing 4 mg [0202] e. Intravenous administration of Memogain salt at dose rate of 5 mg\kg (previously carried out as control)

[0203] Sublingual Report:

[0204] This experimental plan describes the blood and brain pharmacokinetic profiles of the pro-galantamine Memogain maleate and galantamine in female wistar rat following sub-lingual application of the Memogain maleate and galantamine Hydrobromide in various formulations. [0205] a. 5% galantamine in water, 20 μL under tongue containing 1 mg [0206] b. 5% Memogain salt in 10% NEP in water, 20 μL under tongue containing 1 mg [0207] c. 5% Memogain salt in an emulsion, 20 μL under tongue containing 1 mg [0208] d. 20% Memogain salt in an emulsion, 20 μL under tongue containing 4 mg [0209] e. intravenous administration of Memogain salt at dose rate of 5 mg\/g as control

[0210] Both the intranasal and sublingual studies show that beneficial pharmacokinetic (PK) properties were observed with the maleate salt. Similar results are to be expected from the other preferred salts of the invention, when considering the additional experimentation described herein and in light of preliminary studies with nasal or buccal mucosa, which show good uptake across the mucosal membranes of all preferred salts of the invention. The PK data show that Memogain was detected in the brain for extended periods of time, and showed high brain to blood concentration ratios, indicating that very little of the applied prodrug is carried into the blood stream and subsequently degraded. Over time the levels of Memogain in the brain decrease, as levels of galantamine in the brain increase, which indicates cleavage of the prodrug to its active form in the brain of the subject. One example is shown for the intranasal experiment in FIG. 12, sample b.

[0211] The administration of the Memogain salt intranasally provides a very effective method of directing the prodrug specifically to the brain, where it is processed thereby releasing the active compound galantamine.

[0212] Memogain Gluconate:

[0213] Further tests were performed with Memogain gluconate. It has a much larger BBRC than galantamine (see FIG. 6). The pharmacokinetics and brain-to-blood concentration ratios (BBRC) of several galantamine derivatives and their cleavage product galantamine were evaluated after intranasal administration in Swiss albino mice at a dose of 3 mg/kg. After extraction from brain and blood, the drug concentrations were determined by LC/MS/MS.

[0214] For comparison, the BBRC for the parent drug galantamine was also determined. As demonstrated in the figure, the studied pro-galantamines all display larger BBRCs than galantamine, with a particularly large BBRC for Gln-1062 Memogain gluconate is highly water soluble and has no burning sensation to nose, or any taste or smell. Intranasal dosing can be done with simple spray-pump methods, although also many other methods can be used. As Memogain is a pharmacologically inactive precursor of galantamine and was administered intranasally as gluconate, no GI side effects were observed.

Example 8. Memogain Shows Improved Brain Penetration and Low Blood Levels Compared to Galantamine

[0215] Data are shown in FIG. 13. Mice were injected with 3 mg/kg i.v. of either Memogain or galantamine. The data demonstrate clearly that galantamine does not distribute into the brain well (BBRC˜1:1), whereas Memogain has a much higher BBRC (8:1).

[0216] Additional data are shown in FIG. 14 for i. n. administration. A Rat PK study was carried out with 5 mg/kg intranasal (i.n.) Memogain dosing performed under GLP-like conditions. The data demonstrate that Memogain has a much higher BBRC (10:1).

Example 9. Intranasal Memogain is More Potent than Galantamine

[0217] To test whether intranasal Memogain is in-vivo a more effective cognition enhancer than galantamine, the following cognition paradigm was applied. Mice were treated with scopolamine to induce acute amnesia and were then tested for performance in a T-maze, in the absence or presence of oral galantamine or intranasal Memogain (FIG. 7). Clearly, Memogain was more effective than galantamine in reversing the acutely induced amnesia. Mice were challenged with Scopolamine i.p. in a T-maze assay to induce disorientation/amnesia (set to 0% performance recovery). Co-application of galantamine (i.p.) or of Memogain® (i.n.) rescues orientation in the T-maze in a dose-dependent manner.

Example 10. First Pass Effect of Memogain

[0218] The first-pass effect of Gln-1062 was evaluated after intravenous and intraportal dosing of 3 mg/kg in Wistar rats (FIG. 8). Gln-1062 was observed to undergo first-pass effect by rapidly decreasing blood concentration levels independently of whether it was administered i.v. or i.n. In contrast, the concentration levels of galantamine liberated from Gln-1062 by enzymatic cleavage did not decrease similarly rapidly. Moreover, higher maximal concentration levels of Gln-1062 were observed in brain and blood following i.v administration as compared to intraportal administration. From these data, the first-pass effect was estimated to be between 35 and 45%.

[0219] When Gln-1062 was administered intranasally at the same dose, similarly high maximal concentration levels were observed in the brain as after i.v. administration, indicating that uptake into the brain was as efficient as after i.v. administration and with little impairment by a first-pass effect.

Example 11. Intranasal Administration of Memogain Leads to Low Amounts of Liberated Galantamine in Plasma

[0220] The study was performed in dogs. A single dose of 4 mg/kg intranasal Memogain was administered and the plasma levels of Memogain and liberated galantamine were determined as a function of time after administration. As Memogain is preferentially partitioned into the brain, only a small fraction of the pro-drug appears in the blood. The levels of galantamine liberated from Memogain are much smaller, as galantamine is rapidly metabolized and excreted (FIG. 9). This leads to a much reduced likelihood of side effects, considering the small amounts of systemic galantamine present in the blood after i. n. administration.

[0221] The data from the dog experiments demonstrate: [0222] Brain:Blood ratio of Memogain (@120 min post administration)=9 [0223] Brain:Blood ratio of galantamine (@120 min post administration)=1-1.5 [0224] Memogain in blood t½=90 min (conscious animals) [0225] Galantamine t½=6 h (conscious animals) [0226] Low blood levels of galantamine indicates fewer side effects [0227] High brain concentrations of Memogain indicate release of galantamine from Memogain mainly in the brain.

Example 12. Memogain Produces Fewer Gastro-Intestinal Side Effects than Galantamine

[0228] These studies were performed in ferrets that were dosed i.p. with either 20 mg/kg galantamine (maximal tolerated dose), or with 20, 40 and 80 mg/kg Memogain, respectively. At 20 mg/kg Memogain, no adverse effects were observed. From the dose dependency of adverse effects, at least 4 times lower toxicity in this animal model was observed for Memogain, as compared to galantamine (FIG. 10).

[0229] Similarly, much less adverse effects than observed with galantamine were seen in the Irwin assay, respiratory toxicity studies, both performed in rats, and in a cardiovascular toxicity study in dogs.

Example 13. Memogain is at Least 10 Times Safer than Galantamine

[0230] This study was performed in dogs, and both drugs were administered as intravenous bolus. The lower toxicity of Memogain is due to the much lower steady-state plasma levels of galantamine resulting from enzymatic cleavage of the pro-drug (FIG. 11).

[0231] Medical Benefits of Galantamine Pro-Drugs and their Formulations for Transmucosal Delivery to the Nasal and Buccal Cavity:

[0232] The key benefits are as follows:

[0233] 1. Higher bioavailability and higher effectiveness in the target organ

[0234] 2. Lower levels of peripheral side effects

[0235] 3. Pharmacokinetics can be adjusted to medical needs (sustained delivery)

[0236] 4. Dosing not limited by GI adverse effects

[0237] 5. Faster and stronger onset of medical benefit

[0238] 6. Up-titration of dose (to enhance compliance) not needed

[0239] 7. Immediate administration of efficacious doses

[0240] 8. Improved patient compliance

[0241] Higher bioavailability in the brain and higher effectiveness as a cognition enhancer was demonstrated by pharmacodynamics studies using suitable cognition paradigms in animal models of cognitive impairment. Dramatically lowered incidences of gastro-intestinal adverse effects, i.e. retching and emesis, were shown for intranasal delivery of Memogain in comparison to oral administration of identical doses of Memogain or galantamine. For intranasal delivery of the pro-galantamine Memogain, even at very high doses, GI-related side effects had practically disappeared, as the combined result of better brain penetration of the lipophilic pro-drug and avoidance of the gastro-intestinal tract during drug delivery.

[0242] In summary, the oral administration of Memogain and galantamine provide comparable BBB-penetration due to the rapid cleavage of Memogain (to galantamine) post-administration. The Memogain salts provide no noticeable enhanced effect when administered orally at the same concentration.

[0243] Intravenous administration (i. v.) of Memogain compared to galantamine demonstrates a vastly improved BBB-penetration for Memogain due to its more hydrophobic nature. The i. v. administration of galantamine provides only a very minor (if any) advantage in comparison to oral delivery of galantamine, as the active compound itself is relatively stable when compared to Memogain and is not susceptible to esterase cleavage.

[0244] Transmucosal administration (intranasal; i. n.) reveals unexpected enhanced effects with respect to Memogain, and particularly the salts of Memogain. The i. n. administration of the salts of Memogain show further improved BBB-penetration.

[0245] Brain penetration of galantamine is not enhanced by i. n. administration of galantamine, as the hydrophilic nature of the molecule prohibits effective penetration regardless of administration route. The i. n. administration of galantamine may avoid some common side effects (Leonard et al (2007)) of galantamine by avoiding administration through the digestive tract. The efficacy as cognition enhancer of the molecule is however not enhanced due to the remaining poor BBRC.