NZ204849A - Hypotensive compositions based on 1-(3-sulphamoyl-4-chloro-benzamido)-2-methylindoline and 8-(3-tert-butylamino-2-hydroxypropoxy)-thiachroman - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £04849 2 04 8 Priority Date(s): Complete Specification Filed: 2.. ciass: Date:'!""(j J. ffiM P.O. Journal. No: . /sm NO DRASIIiGS -8 JUU985 NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION SYNERGIC ANTIHYPERTENSIVE PHARMACEUTICAL COMPOSITION p^VVe ADIR, a French company, of 22 Rue Garnier, F-92200 Neuilly Sur Seine, France, hereby declare the invention for which ^./ we pray that a patent may be granted to igt/ us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 204849 - 1c* - ;The present invention relates to a pharmaceutical composition containing a combination of two active substances, indapamide and 8-(3-tert.-butylamino-2-hydroxypropoxy)-thia-chroman. ;Indapamide, or N-(3-sulphamoyl-4-chlorobenzamido)- ;2-methylindoline , or also 4-chloro-N-(2-methvl-1-indolinyl)- ;3-sulphamoylbenzamide, has been described in Example 1 ;of British Patent No. 1,203,691 as a diuretic that can be used especially for the treatment of arterial hypertension. ;8- (3-tert. -butylajnino-2-hydroxypropoxy) -thiachroman (or the addition salts thereof) is described in Example 2 of British Patent No. 1,308,191 which mentions cardiovascular properties, especially beta-blocking properties. ;It has now beer, found, however, that the two above-mencionea compounds when in combination have unexpected synergist properties making possible their simultaneous therapeutic use. ;The invention therefore relates to a pharmaceutical composition for treating hypertension containing a combination of indapamide and 8-(3-tert.-butylamino-2-hydroxypropoxy)-thiachroinan, or one of the pharmaceutically acceptable addition salts thereof, in a ratio of from 1:15 to 1:1 by weight, it being possible for each of these two compounds to be in the raceinic form or in the form of an optical isomer, and also a therapeutically compatible excipient or carrier. ;For the sake of convenience, 8-(3-tert.-butylamino- ;O A ° A. O ;w "i" w '• y ;- 2 - ;2-hvdroxypropoxy)-thiachroman will be referred to hereinafter as "THPT". ;Pharmacological study. ;The compounds studied according to the invention ;5 were tested, alone and in combination, for functional inhibition of membrane adenylate cyclase. ;The red corpuscles of pigeons have been known for their considerable adenylate cyclase activity since the studies of SUTHERLAND et al. (Adenyl cyclase 1. ;10 Distribution, preparation and properties, J. Eiol. Chem. ;(1962) 237 : 1220-1227). The experiments were carried out on ghosts of erythrocytes (open cells ) prepared from the blood of Strasser pigeons according to the method of ;SALESSE R. and GARNIER J., "Effects of drugs on pigeon ;15 erythroctye membrane and asymmetric control of adenylate cyclase by the lipid bilayer" (Biochem. Biophys. Acta ;(1979) 554 : 102-103). ;The suspensions obtained were incubated for twenty minutes in hypotonic buffer with a volume of the tested ;20 product at the final concentration desired. The adenylate cyclase activity was determined according to the method of BIRNBAUMER L. et al. (J. Biol. Chem. ;(1969) 244 : 2468-3476) and RAMACHANDRAN J.; LEE V. ;(Biochem. Biophys. Res. Commun. (1970) 41 : 358-366). ;25 The final concentrations of reagents were ATP 2 mM ;3 2 ;having 1 jiCi of [a- J ]P ATP, theophylline 4 mM, ;- 3 - ;2 A * r phosphocreatine 10 mM, creatine kinase 0.5 g/litre, KgCl2 7.5 mM, tromethamine HC1 ("TR1S" HC1) 10 mM, pH = 7.4.

The total volume was 75 microlitres and the Q number of cells per tube was approximately 10 .

The production of cyclic AMP (cAMP) was stimulated either by 0.05 mM of isoproterenol in the presence of 0.1 mM of GTP, or by 10 mM of sodium fluoride. The compound was added to the final concentration required. 10 The reaction was stopped after 15 minutes at 37°C by adding 300 microlitres of 0.5 N hydrochloric acid and by placing the mixture over a boiling water bath for 3 minutes. The tubes were then removed from the water bath and the contents were neutralised by 300 micro-15 litres of 1.65 N imidazole.

After centrifugation (10 minutes, 4000g) , 500 micro-litres of the supernatent solution were poured into a neutral activated alumina column and were eluted with 2.6 ml of imidazole, 10 mM, pH = 7.5. These columns had 20 a yield of cAMP of 95 %.

The radioactivity of the samples was measured in a scintillation counter "Packard Tricarb", using the Cerenkov effect after adding 10 ml of 1 %• aqueous solution of 7-arnino-1 , 3-naphthalenedisulphonic acid to 25 the eluate (counting yield 65 %).

There were determined, according to a logarithmic scale, three concentrations above and three concentra tions below the concentration for which, in vitro, on the mesenteric artery of rats an inhibition of half of the vasoconstriction induced by noradrenalin could be observed.

The results are given as the average of three tests in picomoles of cyclic AMP produced per minute and per milligramme of membrane phospholipids.

It can be seen that the indapamide and THPT subjected to this test inhibit the activation of adenylate cyclase stimulated by isoproterenol or sodium fluoride: the. quantity of cAMP produced decreases. The nature of the effect on the production of cAMP which is observed is dependent on the concentration of the compound used. The active concentration of each compound producing an inhibition of 25 % (AC25) and 50 % (AC^Q) was determined graphically and then that of the mixtures thereof at those concentrations: Indapamide (m.w. = 365.89): AC25 = 9 x 10 ^ mole/litre AC50 = 3 x 10 4 mole/litre THPT HCl (m.w. = 331.90): AC25 = 1•2 x 10~5 mole/litre ■ -5 AC^q = 7 x 10 mole/litre The following Table shows the precentage inhibition obtained with each of the 4 mixtures of the two compounds at those concetrations: 2 0'^ 4 TABLE Indapamide 25 % Indapamide 50 % THPT 25 % 45 % 62 % THPT 50 % 62 % 75 % It can be seen that'the inhibition obtained with the mixture of the two compounds is clearly superior to that obtained with each compound separately. For example, _5 with a mixture at the concentrations of 9 x 1Q mole/ litre of indapamide and 1.2 x 10~^ mole/litre of THPT 45 % inhibition is obtained which is only achieved -4 -5 by 2.5 x 10 mole/litre of indapamide or by 5 x 10 mole/litre of THPT, that is to say approximately from 3 to 4 times the quantity necessary of each of the compounds when taken separately. The two effects 15 corresponding to 25 % inhibition are therefore multiplied in their global effect and result in a 45 % inhibition of the activity of the enzyme.

Discussion : Since THPT is known as a beta-blocker, its inhibit-20 ory activity on adenyl cyclase combined with an extracellular beta-receptor could be foreseen. In contrast, it was not to be expected that an anti-hypertensive 2 0 •, S A diuretic such as indapamide would have a similar activity and that, above all, the activity of these two compounds would be combined: in fact, the dose/ activity curve of these ccmpounds, and especially 5 their and show that they act in multiplying synergism. cAMP is a second intracellular messenger triggering the start of cellular functions. By inhibiting adenyl cyclase, all states of cellular hyperactivity, such as 10 those existing in hyperactivity of the thyroid, hypertension, hypersensitivity, etc., are slowed down. As a result, the combination of the tvo ccmpounds acting in synergism according to the invention is indicated especially for treating states of beta-dependent hyper-15 activity such as are encountered in hypertension, especially in cases of severe arterial hypertension together with renal insufficiency, or in disorders such as hyperactivity of the thyroid.

The pharmaceutical compositions according to the 20 invention are preferably administered by the oral route and may be in the form of tablets, coated tablets, capsules, suspensions, etc. They may contain especially from 0.8 to 3 mg of indapamide and from 3 to 12 mg of THPT, or one of the pharmaceutically acceptable addition 25 salts thereof, and also the excipients or carriers customary for oral forms, and they may be administered in one or two daily doses.

Claims (4)

- 7 - 20484 9 EXAMPLE: 90 mg TABLET Indapamide 1.25 mg 8-(3-tert.-butylamino-2-hydroxypropoxy)- thiachroman hydro.chloride 5.00 mg 5 stearic acid 0.90 mg sodium carboxymethy2 starch 3.00 mg microcrystalline cellulose 33.38 mg lactose 35.75 mg calcium hydrogen phosphate 10.00 mg 10 colloidal silica 0.27 mg magnesium stearate 0.45 mg This tablet may be coated. 204849 8 WHAT Wi: CLAIM IS:

1. A pharmaceutical composition for treating hypertension containing a combination of N-(3-su1phamoyl-4-chlorobenzamido)-2-methylindoline and S-(3-tert.-butylamino-2-hydroxypropoxy)-thiachronian or one of the pharmaceutical^ acceptable addition salts thereof, in a ratio from 1:15 to 1:1 by weight, it being possible for each of these two compounds to be in the racemic form or in the form of an optical isomer, and also a therapeutically compatible excipient or carrier.

2. A pharmaceutical composition according to claim 1, characterised in that it contains from 0.8 to 3 mg of N-(3-sulphamoyl-4-chlorobenzamido) -2-methylindoline and from 3 to 12 mg of 8-(3-tert.-butylamino-2-hydroxy-propoxy)-thiachroman or one of the addition salts thereof.

3. A pharmaceutical composition intended for administration by oral route according to claim 2, characterised in that it contains 1.25 mg of N-(3-sulphamoyl-4-chlorobenzamido)-2-niethylindoline and 5 mg of 8-(3-tert.- butylami no-2-hydroxypropoxy)-thiachroman hydrochloride.

4. A pharmaceutical composition as claimed in any one of the preceding claims and substantially as herein described with reference to any example given. M(L •; er.cs. Cj)