DE3805744A1 - Phenyl carbamate - Google Patents

Abstract

(S)-N-Ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenyl carbamate as the free base or in the form of the acid addition salt is useful as a pharmaceutical, in particular for systemic transdermal administration.

Description

The present invention relates to a new phenyl carbamate anticholinesterase effect.

In particular, the invention relates to the (S) -N-ethyl-3 - [(1-di methylamino) ethyl] -N-methyl-phenyl-carbamate of the formula I.

in the form of the free base or as an acid addition salt.

As can be seen from this formula, is in the form of the free Base the mark of rotation of the compound of formula I. (-). However, in the form of the acid addition salt (+) or (-) be. For example, the hallmark is the rotation of the hydrogen tartrates (+). The present invention covers independently of their rotation mark the free base shape as well as the Acid addition salt forms.

The racemic mixture (±) -N-ethyl-3 - [(1-dimethylamino) ethyl] - N-methyl-phenyl-carbamate in the form of its hydrochloride is from the  European patent application 1 93 926, where it is known as RA₇HCl is identified.

In accordance with this disclosure, the racemate is obtained in the form of the free base by amidation of α- m-hydroxyphenylethyl dimethylamine with a corresponding carbamoyl halide. The resulting compound and its pharmacologically acceptable acid addition salts, which can be prepared from the free base in a known manner, are disclosed as acetylcholine esterase inhibitors in the CNS.

It has now surprisingly been found that the (-) - Enantio mers of formula I and its pharmacologically acceptable acid addition salts, hereinafter referred to as compounds referred to lying invention, a particularly pronounced and have selective inhibition of acetylcholinesterase.

These findings are unexpected, especially since it was not believed that the dialkylaminoalkyl side chain, which is the optically active Center contains, is mainly responsible for the Acetylcholinesterase inhibitory activity of the phenyl carbamates.

The compounds according to the present invention were previously in the Literature not specifically disclosed anywhere. The free base can run out the racemate by separating the enantiomers in agreement with known methods, e.g. B. by using Di-0,0'- p-toluene-tartaric acid. The acid addition salts can be prepared in a manner known per se from the free base will. These include, for example, the hydrogen tartrate.

The compounds according to the present invention show pharma ecological effect as indicated in standard tests therefore useful as pharmaceuticals. You can reach the CNS quickly after s. c., i. p. or p. o. Administration in rats. You practice one  Brain region selective inhibition of acetylcholinesterase activity with the hippocampus and cortical enzymes more inhibited as acetylcholinesterase resulting from the Striatum and Pons / Medulla. In addition, they have a long duration of action.

For example, the following results illustrate the pharmacological Profile of the compounds according to the present invention in Comparison with the corresponding isomers and racemates. Compound A is the compound of formula I in the form of its hydrogen tartrates. Compound B is the optical isomer of the above Salt. C denotes the racemic mixture of the compound of Formula I and its optical isomer in the form of the hydrochloride.

In vitro experiments Electrically induced ³H-acetylcholine release from Rat hippocampal slices

Electrically induced ³H-acetylcholine (³H-ACh) release from rat rat hippocampus sections is a useful one in vitro model for the investigation of presynaptic muscarinic Autoreceptor agonists and antagonists. This model can too be used as an indirect method of evaluating Medicines that inhibit acetylcholinesterase (AChE). The Inhibition of AChE activity leads to the accumulation of endogenous ACh, which then with presynaptic muscarinic auto-receptors interacts and the further release of 3 H-ACh inhibits.

Rat hippocampus sections (Wistar strain, 180-220 g) are made by cross-chopping whole hippocampus sections with a McIlwain tissue chopper at a distance of 0.3 mm. Hippocampal sections obtained from 3 rats are incubated for 30 minutes at 23 ° C in 6 ml Krebs-Ringer containing 0.1 uCi³H-choline and transferred to the superfusion chamber. The superfusion takes place with Kreb's medium containing 10 µM Hemicholinium-3 in a rat of 1.2 ml / min. at 30 ° C instead. The collection of 5 minute fractions of the superfusate begins 60 minutes after the superfusion. Two periods of electrical stimulation (2 Hz rectangular pulses 2 msec, 10 mA, 2 min.) Are applied after 70 minutes (S ₁) and after 125 minutes (S ₂) superfusion. The test substances are added 30 minutes before S ₂ and are present in the super fusion medium up to 145 minutes of superfusion. At the end of the experiments, the sections are dissolved in concentrated formic acid and the tritium content in the superfusate and in the loosened sections is determined. Tritium outflow is expressed as a fraction of the tritium outflow per minute. Electrically induced tritium outflow is calculated by subtracting the extrapolated basal tritium outflow from total tritium outflow during the two minutes of electrical stimulation and the following 13 minutes and is expressed as a percentage of the tritium content at the beginning of the sample collection. Drug effects in the case of tritium outflow caused by stimulation are expressed as ratios S ₂ / S ₁. All experiments are carried out in duplicate, using a programmable 12-channel superfusion system. A computer program is used for the calculation.

In this test, compound A inhibits electrically induced 3 H-ACh release from hippocampal sections in approximately 40% (100 µM), while Racemat C (100 µM) inhibits in approximately 25%. The inhibitory effects of compound A and racemates C can by Atropine can be antagonized. These results are consistent with AChE inhibitory activity. Compound B is inactive this model.  

Inhibition of acetylcholinesterase in different regions of the world Rat brain

In this test, AChE preparations from different regions are used of the rat brain (cortex, hippocampus and striatum) and the IC₅₀ (inhibitory concentrations in µM) determined. The enzyme preparations are pre-incu 15 minutes before the determination with the inhibitor beer.

The AChE activity is according to the by Ellman (Arch. Biochem. Biophys. 82, 70, 1959). The rat brain tissue is pH 7.3 in cold phosphate buffer (0.25 mM) containing 0.1% Triton X-100, homogenized. After Centrifugation are made as aliquots of the floating float Enzyme source used. The enzyme comes with different concents Pre-incubated trations of the inhibitor. After different times the substrate (acetylthiocholine iodide 0.5 mM) is added and the remaining activity measured.

The results are shown in Table 1 below:

Table 1

As can be seen from this table, the AChE inhibition is with Compound A somewhat higher than with racemate C, while Ver bond B is significantly less active.  

Acetylcholinesterase inhibition ex vivo in different regions of the Rat brain

30 minutes after administration of various doses of ver Binding A is the AChE activity in different regions of the Rat brain measured ex vivo. The method is described above. The IC₅₀ values found are 7 µmol / kg p. o. in the striatum, 4 µmol / kg p. o. in the hippocampus and 2 µmol / kg p. o. in the cortex. The IC₅₀ obtained after administration of the racemate C are for all regions examined 2 to 3 times higher. Six hours after Administration of compound A (10 µmol / kg p. O.) Is the AChE im Striatum still inhibited by 16% at the same time the activities in the cortex and hippocampus by 39% and 44%, respectively are inhibited.

In vivo experiments Influencing dopamine metabolism

Male OFA rats (150-200 g) are used for both acute and also used for subchronic experiments. The animals will held during 12 hour periods of light and dark. The animals are always killed between 11 a.m. and 1 p.m. The Brains are cut out immediately, then by the method by GLOWINSKI and IVERSEN, J. Neurochem. 13, 655 (1966) on ice dissected, frozen on dry ice and the tissue samples to the Analysis stored at -80 ° C.

Dopamine and its metabolites DOPAC (3,4-dihydroxyphenylacetic acid) and HVA (homovanillic acid) are found in brain tissue extracts certainly. These are obtained by homogenizing stored brain tissue samples in 0.1 N HCl containing 0.05 mM Acorbic acid, and subsequent centrifugation. It will striatal and cortical tissues used.  

The determination of the metabolites is carried out either under Application of gas chromatography / mass fragmentography (GCMS) - Technique described by KAROUM et al., J. Neurochem. 25, 653 (1975) and CATABENI et al., Science 178, 166 (1972) or the fluorometric method as by WALDMEIER and MAITRE, analyte. Biochem. 51, 474 (1973). For the GCMS method tissue extracts are made by adding known amounts deuterated monoamines and their respective metabolites as internal standards.

The dopamine metabolism in the striatum is after administration of the Compounds A and B and racemate C increased (This Eigen shaft is a consequence of the connections mentioned induced acetylcholine accumulation.). Nevertheless, Ver bond A more active than compound B and racemate C in increasing the striatal dopamine metabolite concentrations.

Muscarinic and nicotine effects on brain glucose utilization

Changes in the functional activity of the CNS are ver associated with a modified deoxyglucose (DOG) utilization in the Brain. These can be found simultaneously in different regions of Brain can be made visible when using the car radio graphic method of Sokoloff et al., J. Neurochem. 28, 897 (1977). The administration of cholinergic agents either directly (muscarinic agonists) or indirectly (accumulation of Acetylcholine) has a characteristic effect in this model "Finger pressure" pattern by changing regional glucose metabolism.

Male Wistar rats (150-200 g) are used. The effect substances are given to animals in different doses and on ver different ways (i.v., p.o., i.p.) administered. [14C] -2-deoxy Glucose (125 µC / kg) is killed 45 minutes before the animals  are injected. The brains are cut out immediately, frozen at -80 ° C and then sliced with a thickness cut from 20 µm. The optical densities of the radiographic Images are modified according to a modification by Sokoloff et al. measured.

According to p. o. administration of compounds A and B (7.5 μmol / kg) are significant changes in the DOG utilization in ver different regions of the rat brain were observed. The effect of Compound A is stronger than that in the first 30 minutes from compound B. The most pronounced changes will be in the facial regions and the anteroventral thalamus as well found in the lateral habenula nucleus.

Acetylcholine levels in different regions of the rat brain

The effects of compounds A and B and racemate C as AChE inhibitors in vivo are determined by measuring ACh levels in different regions of the rat brain at different times after administration of the active ingredient.

OFA rats (200-230 g) are used. The animals are killed set upside down by microwave radiation (6 kW Operating power 2450 Mhz exposure 1.7 sec., Pueschner microwave energy technology, Bremen). The brains are removed dissected according to Glowinski and Iversen (1966) and until analysis Stored at -70 ° C. The brain parts are homogenized in 0.1 M. Perchloric acid containing internally deuterated standards of ACh-d₄ and Ch (choline) -d₄. After centrifugation, endogenous ACh and Ch along with their deuterated variants with dipicrylamine (2,2 ', 4,4', 6,6'-hexanitrodiphenylamine) in dichloromethane as Ion pairs extracted. The Ch parts are made with propionyl chloride derivatized and the resulting mixture of ACh and propylcholine derivatives are demethylated with sodium benzene thiolate and  by mass fragmentography according to Jenden et al., Anal. Biochem., 55, 438-448, (1973).

A single administration of 25 µmol / kg o. P. increases the ACh concentration in the striatum, cortex and hippocampus. The maximum effect is approximately 30 minutes after oral administration reached and decreased in the next 3-4 hours. in the Cortex and hippocampus are the ACh levels at 4 hours significantly higher compared to controls. The effects are depending on the can. The influence of compound B is significant weaker than the one triggered by the racemate C, and the influence of racemate C is significantly weaker than the one that is triggered by connection A.

The compounds of the present invention are also indicated as well tolerated and orally active and they have a long Duration of action, e.g. B. in the above and other standard tests.

The compounds of the present invention are therefore useful for the treatment of senile dementia, Alzheimer's disease, Huntington's Chorea, tardive dyskinesia, hyperkinesia, mania, acute confusion, Down's syndrome and Friedrich's ataxia.

An indicated daily dose is around 0.1 up to approx. 25 mg, e.g. B. from about 0.1 to about 5 mg, a compound of the present invention, together with a fixed or liquid carrier or diluent.

In accordance with the foregoing, the invention also sees a compound according to the present invention prior to use as Pharmaceutical, e.g. B. for the treatment of senile dementia, Alzheimer's Disease, Huntington's Chorea, Tardive Dyskinesia, Hyperkinesia, mania, acute confusion, Down's syndrome and Friedrich's ataxia.  

The invention also provides pharmaceutical compositions containing a compound according to the present invention, with at least one pharmaceutical carrier or diluent. Such compositions can be made in a conventional manner will.

In the following example, the temperatures are uncorrected and given in degrees Celsius.

Example 1 (S) -N-ethyl-3 - [(1-dimethylamino) ethyl] -N-methylphenyl carbamate

130 g (±) -N-ethyl-3 - [(1-dimethylamino) ethyl] -N-methyl-phenyldicarbamate and 210 g (+) - di-0,0′-p-toluene tartaric acid monohydrate are dissolved while heating in 1.3 liters of methanol / water (2: 1). After cooling, the precipitated salt is filtered and recrystallized three times from methanol / water (2: 1). The (S) -enantiomer is released by partitioning between 1N NaOH and ether.
[ α ] = -32.1 ° (c = 5 in ethanol).

The hydrogen tartrate of the title compound (from ethanol) melts at 123-125 °.
[ α ] = + 4.7 ° (c = 5 in ethanol).

The present invention further relates to systemic transdermal Use of the phenyl carbamates of the formula I ′,

wherein

R₁hydrogen, lower alkyl, cyclohexyl, allyl or Benzyl, R₂ means hydrogen, methyl, ethyl or propyl, or R₁ and R₂ together with the nitrogen to which they are attached form a morpholino or piperidino radical, R₃ means hydrogen or lower alkyl, R₄ and R₅ are the same or different and each lower alkyl means and the dialkylaminoalkyl group in meta, ortho or para position,

as free bases or in the form of pharmaceutically acceptable ones Acid addition salts.

The compounds of formula I 'and their pharmaceutical acceptable acid addition salts as well as their preparation and their use as acetylcholinesterase inhibitors are from the above European patent application 1 93 926 known.

The compounds of formula I 'include z. B. the above defined compound A and the racemate C.  

It has now surprisingly been found that the compounds of formula I 'as free bases or in the form of pharmaceutical acceptable acid addition salts, hereinafter referred to as compounds listed for administration according to the present invention, a Unexpectedly good skin penetration when percutaneously be administered.

Penetration of the skin of the compounds for administration aloud The present invention can be performed in standard in vitro or in vivo Tests are observed.

An in vitro test is the well known diffusion test that is run can be in accordance with the principles as they in GB 20 98 865 A and by T. J. Franz in J. Invest. Dermatol. (1975) 64, 194-195. Solutions that the active Contain active substance in unlabelled or radiolabelled form, become more intact on one side of isolated pieces human skin or hairless rat skin on an area of approx. 2 cm² attached. The other side of the skin is in contact with physiological saline. The amount of active ingredient in the saline solution according to known methods measured, e.g. B. by HPLC or spectrophotometric techniques, or by determining radioactivity. For example, in this Test the following penetration rates when using rat skin found:

Compound A defined above: 23.6 ± 14.9% Compound of formula I in the form of the free base: 28.0 ± 8.2%

Furthermore, it was found that the transdermal administration of the Compounds for administration according to the present invention long-lasting and constant inhibition of the acetylcholinesterase effect caused as shown in standard tests with  slow onset of effects, in terms of tolerability of these compounds is particularly advantageous.

For example, inhibition of acetylcholinesterase has been shown in various Regions of the rat brain measured ex vivo transdermal administration of the compounds for administration according to the present invention and compared to the inhibition of how it was obtained in various ways after administration.

The compounds are dissolved in or diluted with n-heptane up to a concentration of 1 or 3 mg / 20 µl. Masculine Rats (OFA strain, approx. 250 g) are shaved in the neck region and applied the solution to the skin with a micropipette. The Application site is immediately covered with a thin plastic film and covered with a plaster. The animal has no access to the patch. At different times after administration, the animals killed by decapitation and the remaining AChE effect measured.

For example, transdermal administration will effect those defined above Compound A is a long-term, dose-dependent inhibition of AChE effect. In contrast to the quick start of the effect either after oral or subcutaneous use (max. 15 and 30 minutes) the AChE inhibition occurs after this route of use (max. <2 hours) only slowly without the brain region-selective To influence AChE inhibition.

The results are shown in Table 2 below. The AChE effect is 24 hours after transdermal application still inhibited in central and peripheral regions. After this Compound A administered orally has no same period Effect on the enzyme, while after the s. c. Administration only the enzyme in the heart is significantly inhibited.  

Table 2

In another aspect, the present invention sees hence a pharmaceutical composition for the systemic transdermal administration containing a compound of Formula I 'as a free base or in the form of a pharmaceutical acceptable acid addition salt, with a pharmaceutical Carriers or diluents which are suitable for the systemic transdermal administration.

It also sees another aspect of the present invention the use of a compound of formula I 'as a free base or in the form of a pharmaceutically acceptable acid addition salt as Active ingredient in the manufacture of a for systemic transdermal Administration of suitable pharmaceutical composition in front.

The active ingredients can be found in any conventional liquid or solid transdermal pharmaceutical composition be administered, e.g. B. as described in Remington's Pharmaceutical Sciences 16th Edition Mack; Sucker, fox and spieser, Pharmaceutical technology 1st Edition, Springer and in GB 20 98 865 A or DOS 32 12 053.

The composition is expediently in the form of a viscous one Liquid, an ointment, a solid reservoir or one fixed matrix. For example, the active ingredient is represented by a fixed reservoir or matrix. The latter will be made from a gel or a solid polymer, e.g. B. one hydrophilic polymer as in the European patent application No. 1 55 229.

The active ingredient can also be incorporated in a plaster.

The compositions for transdermal administration can from about 1 to about 20 percent by weight of active ingredient  Formula I 'as a free base or in the form of a pharmaceutical acceptable acid addition salt included.

The pharmaceutical compositions for transdermal administration can be used for the same indications as for oral or intravenous administration. The amount of too The active pharmaceutical ingredient is administered individually depend on the characteristics of the drug release pharmaceutical compositions made in vitro and in vivo Tests observed penetration rate of the drug, the strength of the active substance, the extent of the skin contact area, the part of the Body, which is based on the formulation and the duration the required effect. The amount of active ingredient and the Area of pharmaceutical composition, etc. can be determined are carried out through routine bioavailability tests, the blood level of the active ingredient after administration of the Active ingredient on intact skin in a pharmaceutical Composition according to the present invention can be compared with the blood levels of the active substance as they are after oral or intravenous Administration of a therapeutically effective dose of pharmacologically active ingredient can be observed.

Is the daily dose of a drug for oral administration given, the choice of an appropriate amount of the drug, which in a transdermal composition according to the present Invention is included depend on the pharmaco- kinetic properties of the active substance, including the Liver passage effect; of the amount of medicine that the skin can be absorbed by the matrix in question for a given application area and in a given period; and the period in which the composition is applied shall be. So can a drug with a high liver passage effect a relatively small amount in the transdermal Need composition compared to the daily oral  Dose since the liver passage effect is avoided. On the other hand is generally a maximum of only approximately 50% of the Drug in the matrix through the skin in a 3 day Period released.

The pharmaceutical compositions according to the present invention generally have z. B. an effective contact area of the drug reservoir on the skin from approx. 1 to about 50 square centimeters, preferably about 2 to 20 square centimeters, and should be used for 1-7 days, preferably 1-3 days.

For example, compound A can be in a 10 mg dose a patch of approximately 10 cm² administered once every three days will.

The following example illustrates the invention.  

Example 2 Preparation of a transdermal composition containing a hydrophilic polymer

Composition:

Compound of formula I ', e.g. B. Compound A20% hydrophilic polymer, e.g. B. Eudragit E 100 ^*) 30% non-swelling acrylate polymer, e.g. B. Durotack 280-2416 ^**) 44% plasticizer, e.g. B. Brÿ 97 ^***) 6%

*) Registered trademark, available from Röhm, Darmstadt, W. Germany **) Registered trademark available through Delft National Chemie Zutphen, Holland ***) Registered trademark, available from Atlas Chemie, W. Germany

The components are acetone or ethanol or another suitable volatile organic solvent added and mixed to obtain a viscous mass. The crowd will on an aluminized polyester film (23 micron thick) under Scattered using a conventional apparatus, with a film of 0.2 mm thick (moist) is formed. You leave the film with Dry the room temperature for 4 to 6 hours. The aluminum foil is then cut into pieces of approximately 10 square centimeters.

Claims (14)

1. Process for the preparation of (S) -N-ethyl-3 - [(1-dimethyl amino) ethyl] -N-methyl-phenyl-carbamate of the formula I. in the form of the free base or as an acid addition salt, characterized in that the enantiomers are separated from the corresponding racemate and the resulting compound of the formula I is obtained in the form of the free base or as an acid addition salt. 2. A method according to claim 1 for the preparation of the hydrogen tartrates of the compound of formula I. 3. A compound of formula 1 in the form of the free base or as an acid addition salt as defined in claim 1. 4. The hydrogen tartrate of (S) -N-ethyl-3 - [(1-dimethyl amino) ethyl] -N-methylphenyl carbamates. 5. A compound according to claim 3 or 4 in a pharma tacitically acceptable form for use as a pharmaceutical. 6. A compound according to claim 3 or 4 in a pharma tacitically acceptable form for use in treatment of senile dementia. 7. A compound according to claim 3 or 4 in a pharma tacitically acceptable form for use in treatment from Alzheimer's Disease. 8. A compound according to claim 3 or 4 in a pharma tacitically acceptable form for use in treatment from Huntington’s chorea, tardive dyskinesia, hyperkinesia, Mania, acute confusion, Down's syndrome or Friedrich's ataxia. 9. A pharmaceutical composition containing one A compound according to claim 3 or 4 in a pharmaceutical acceptable form, with a pharmaceutical carrier or Diluent.   10. A pharmaceutical composition for systemic transdermal administration, comprising a compound of formula I ', in which R₁ is hydrogen, lower alkyl, cyclohexyl, allyl or benzyl, R₂ is hydrogen, methyl, ethyl or propyl, or R₁ and R₂ together with the nitrogen to which they are attached form a morpholino or piperidino radical, R₃ is hydrogen or lower alkyl, R₄ and R₅ are the same or different and each is lower alkyl and the dialkylaminoalkyl group is in the meta, ortho or para position, as a free base or in the form of a pharmaceutically acceptable acid addition salt, with a pharmaceutical carrier or diluent suitable for systemic transdermal administration. 11. A pharmaceutical composition according to claim 10, wherein the compound of formula I 'the (S) -N-ethyl-3 - [(1-dimethyl amino) ethyl] -N-methylphenyl carbamate as the free base or in the form of a pharmaceutically acceptable acid addition salt is. 12. A pharmaceutical composition according to claim 10, wherein the compound of formula I 'the (S) -N-ethyl-3 - [(1-dimethyl amino) ethyl] -N-methylphenyl carbamate in hydrogen is tartrate form. 13. A pharmaceutical composition according to claim 10, wherein the compound of formula I 'the (S) -N-ethyl-3 - [(1-dimethyl amino) ethyl] -N-methylphenyl carbamate as free base or in the form of a pharmaceutically acceptable acid addition salt is. 14. The application of a compound of formula I 'as in Claim 10 defined as a free base or in the form of a pharmaceutically acceptable acid addition salt as the more active Active ingredient in the manufacture of a pharmaceutical Composition that is suitable for systemic transdermal application.