EP2054381A2

EP2054381A2 - Pharmacodynamic hybrids endowed of hypoglycemic and no-donor activities obtained combining hydroxylated derivatives of glibenclamide and nitrooxy-substituted carboxylic acids

Info

Publication number: EP2054381A2
Application number: EP07804717A
Authority: EP
Inventors: Aldo Balsamo; Vincenzo Calderone; Simona Rapposelli; Piero Marchetti; Scilla Torri
Original assignee: Universita di Pisa
Current assignee: Universita di Pisa
Priority date: 2006-08-07
Filing date: 2007-08-06
Publication date: 2009-05-06
Also published as: WO2008017925A2; ITPI20060103A1; WO2008017925A3

Abstract

Compound featuring a hypoglycemic action and in the meantime a release of nitric oxide (NO), said compound having the following general formula (I) : where at least one among R, R1, and R2 is a substitute comprising an nitroxy-ester group bound to a acyl aliphatic, aromatic or aliphatic-aromatic group. The compound can be in particular, used to treat patients affected by NO endogenous deficit responsive to diabetes mellitus of type 2.

Description

TITLE

PHARMACODYNAMIC HYBRIDS ENDOWED OF HYPOGLYCEMIC AND NO-DONOR ACTIVITIES OBTAINED COMBINING HYDROXYLATED DERIVATIVES OF GLIBENCLAMIDE AND NITROOXY-SUBSTITUTED CARBOXYLIC ACIDS

DESCRIPTION

Field of the invention

The present invention relates to a class of compounds capable of an hypoglycemic activity and at the same time of releasing in vivo of nitric oxide (NO) .

Furthermore, the invention relates to a pharmaceutical composition that can be used to treat patients affected by NO endogenous deficit in presence of diabetes mellitus of type 2.

Description of the prior art

As well known, diabetes mellitus of type 2 is a disease characterized by the incapacity of the body to give an appropriate response to the action of insulin delivered by pancreas.

Two factors exist, in particular, that can cause this disease to set in. On the one hand an insulin- resistance, on the other hand a deficit of insulin secretion. Hyperglycemic state associated with the diabetic disease is a causal factor at the basis of alterations of the circulatory system. Between the many mechanisms responsible of the correlation between hyperglycaaemia and cardiovascular diseases, an important role is taken by an imbalance of the oxidative systems, an involvement of vascular inflammatory processes, an activation of intracellular signals.

All these processes, in any case, contribute to determine an endothelial outline dysfunction that, through a reduced biosynthesis of nitric oxide (NO) by the endothelium, represents a main cause of the various cardiovascular manifestations owing to diabetes mellitus.

Furthermore, treating diabetes mellitus of type 2 as a monotherapy, i.e. supplying a single drug, is often not satisfactory, and administering more drugs having different mechanisms of action, so called pharmacologic "cocktails", is very common.

However, a treatment with a pharmacological cocktail has some drawbacks, such as an unpredictable pharmacodynamic and/or pharmacokinetic interaction between the different drugs, a more difficult execution of the posology for a patient, forced to have more drugs and sometimes in different times of the day and, normally, a lower "compliance" by the patient same.

In the last years, the study of drugs so-called "hybrid", having a double pharmacodynamic profile, (a single molecule having two or more mechanisms of action) , has developed as a promising field of search. This approach has been addressed to both giving improved pharmacotherapeutic features and/or limiting adverse effects of one drug.

Among the strategies used in the development of such hybrid drugs, a particular success has been achieved by the conjugation of known "native" drugs with further molecular portions capable of releasing nitric oxide (NO) . The many beneficial effects of NO, among which, for example, triggering vasodilation, preventing platelet aggregation and providing cardioprotective action, can in fact be desirable additional effects and become an interesting complement to an already existing pharmacologic action typical of the native drug.

In literature many examples are described of

"pharmacodynamic hybrids" where a "native" drug has been equipped also with an NO-donor action (M. C.

Breschi et al, J Med Chem, 49, 2006, 2628-2639; P. Del

Soldato, WO0230867, 2002).

On this strategy, the use of pharmacodynamic hybrids capable of providing an NO-donor/hypoglycemic joint action can be useful to treat diabetes mellitus of type 2 and of cardiovascular diseases to this associated.

Summary of the invention

It is therefore a feature of the present invention to provide a compound capable of associating to a hypoglycemic activity a graduated and modulated release of nitric oxide (NO) .

It is another feature of the present invention to provide a pharmaceutical composition of dual type capable of opposing to the endocrine/metabolic typical pathological aspects of diabetes mellitus of type 2.

It is also a feature of the present invention to provide a pharmaceutical composition capable of assuring a correct development 'of jeopardized cardiovascular functions owing to endogenous NO deficit, due to endothelial dysfunction of diabetic origin.

It is also a feature of the present invention to provide a compound that has not the typical side effects of the drugs of the prior art.

These and other features are accomplished with one exemplary compound, according to the invention, whose main feature is to have an hypoglycemic action and it releases in the meantime nitric oxide (NO) said compound having the following general formula (I) :

where at least one among R, Ri, and R₂ is a substitute comprising a nitroxy-ester group bond to a acyl aliphatic, aromatic or aliphatic-aromatic group.

In particular, the acyl aliphatic group can be linear, or alternatively, branched (C2-C12) .

The acyl aromatic group can be a substitute shown by the following formula (II) :

where :

— X is selected from the group comprised of: a nitrogen atom, a CH,

— R₃ is selected from the group comprised of: a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an iso-propyl group, a propyl group, a butyl group, an iso-butyl group. The acyl aliphatic-aromatic group can be a substitute group shown by the following formula (III) :

where :

— A is selected from the group comprised of: a methylene group, an linear alkyl group (C2-C4), a branched group, for example -CH (CH₃) , -CH (CH₂-CH₃) , -CH (iso-propyl) .

~ X is selected from the group comprised of: a nitrogen atom, a CH,

~ R₃ is selected from the group comprised of: a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an iso-propyl group, a propyl group, a butyl group, an iso-butyl group.

In particular, the radicals R, R₁, and R₂ that are not one of the substitutes above described, are hydrogen atoms . Advantageously, the substitute group may have configuration cis-, or alternatively, configuration trans-, with respect to the CH-NHCO- bond.

For example, the compound shown by the general formula (I) is 5-chloro-N- [2- [4- ( (4' -trans- [ (nitroxy) methyl] benzoyloxy) cyclohexylcarbamoylsulpham oyl) phenyl] ethyl] -2-methoxy-benzamide, hereafter indicated as DK315.

According to another aspect of the invention a synthesis process of a compound of general formula (I) provides a condensation reaction between an hydroxylate derivative of a sulfonylurea and a carboxylic acid.

For example, a synthesis of the above described hydroxy-sulfonylureic derivative can be carried out according to known methods, given in literature, see for example R. A. Hill et al Bloorg Med Chem, 11, 2003, 2099-2113. Advantageously, the condensation reaction between the hydroxylate derivative of sulfonylurea and carboxylic acid is carried out in the presence of dicyclohexylurea (DCC) and of a catalytic amount of 4- dimethylaminopyridine (DMAP) . In the reported example, the hydroxylate derivative is a hydroxylate compound on the cyclohexylic ring of glibenclamide.

Preferably, the hydroxylate derivative of glibenclamide is a active metabolite thereof, for example:

— 4- trans-hydroxyglibenclamide (M-I) ,

— 3-ci.s-hydroxyglibenclamide (M-2) .

According to a further aspect of the invention a pharmaceutical composition for treatment of diabetes mellitus of type 2 comprises a measured amount of at least one compound having general formula (I) as above shown and described.

In particular, the functional groups present in the "native" drug are capable of assuring the conjugation with suitable linker having NO-donor groups through the production of easily hydrolyzable in vivo bonds, such as the ester bond. Therefore, the pharmaceutical composition that is obtained is capable of opposing to the typically endocrine/metabolic pathological aspects of diabetes mellitus of type 2, owing to the pharmacodynamic profile of the "native" drug, secretagogue of insulin, and at the same time represents an exogenous source of NO, capable of assuring a correct development of its well known cardiovascular functions, jeopardized by the endogenous NO deficit, due to an endothelial dysfunction of diabetic origin.

In particular, in addition to at least one of the compounds above described, the pharmaceutical composition can comprise also pharmacologically acceptable excipients

Hereafter examples are given of a possible synthesis process of a compound, according to the present invention, in particular DK315.

EXAMPLE 1

Synthesis of 5-chloro-N- [2- [4- ( (4' -trans- [ (nitroxy) methyl] benzoyloxy) cyclohexylcarbamoylsulpham oyl) phenyl] ethyl] -2-methoxy-benzamide (DK315) .

To a solution of 5-chloro-N- [2- [4- ( (4' -trans- hydroxy) cyclohexylcarbamoylsulphamoyl) phenyl] ethyl] - 2-methoxy-benzamide (250 mg, 0.49 mmol) and A- [ (nitroxy) methyl] benzoic acid (97 mg, 0.49 mmol) in CH₂Cl₂ dicyclohexylurea (DCC) (122 mg; 0.59 mmol) and 4-dimethylaminopyridine (DMAP) in an a catalytic amount have been added. The suspension has been stirred vigorously at room temperature for about 3h. after this period, the precipitate formed during the reaction is filtered and then the filtered matter has been concentrated at low pressure. The raw product obtained is then purified by means of column chromatography using as eluent a mixture of CHCl₃/MeOH (9.5:0.5) to provide the desired compound as solid white.

Yield: 32%(110mg, 0.16 mmol) Melting point: 85-87°C ¹H-NMR (CDCl₃) δ: 1.09-2.04 (m, 8H) ; 3.02 (t, 2H, J = 6.7Hz) ; 3.65-3.76 (m, 3H) ; 3.81 (s, 3H) ; 4.88-4.96 (m, IH) ; 5.46 (s, 2H) ; 6.44 (d, IH, J= 6.7 Hz) ; 6.88 (d, IH, J = 8.9 Hz) ; 7.35-7.46 (m, 5H) ; 7.85-7.89 (m, 3H) ; 8.03 (d, 2H, J=8.2 Hz) ; 8.13 (d, IH, J = 2.7 Hz) . 1³C-NMR (CDCl₃) δ: 29.83, 30.32, 34.00, 35.75, 40.81, 48.26, 49.52, 56.47, 72.59, 73.82, 113.10, 122.73, 126.88, 127.52, 128.52, 129.69, 130.14, 131.53, 131.87, 132.60, 137.32, 145.49, 156.05, 164.30, 165.34, 168.25, 169.18. Elementary Analysis :

C_3IH₃₃N₄O_I0SCI C H N

Calc% 54 .03 4. 83 8. 13

Trov% 54 .27 5. 02 7. 92

The following are the experimental results of some tests carried out on the compound DK315 for evaluating the secretagogue effects of insulin and the release of nitric oxide (NO) , potentially useful for treatment of various consequences of diabetes mellitus of type 2. Experimental Results

A functional study has been carried out on the effects of M-I and DK315 in isolated human pancreatic islets, by means of digestion of the gland with collagenase and following purification by density gradient .

For the digestion operation the pancreas has been prepared by eliminating any surplus tissue (adipose tissue, vascular tissue etc.) and using an appropriate parts of the gland (normally body and tail) . For the digestion a collagenase enzyme has been used (Roche, collagenase P) . The pancreatic duct has been incannulated and the digesting solution (collagenase, 1,5 mg/ml) , which had been solubilised in 200 ml of Hanks' Balanced Salts (HBSS) with 2% of human albumin (Human-Albumin® Biagini 20%) , has been slowly injected for stretching the tissue. After relaxation, the gland has been put in a glass beker and arranged in a thermostated water bath at a temperature of 36,5°C. The action of collagenase has been controlled a first time after 8 minutes and then each 3 minutes, examining an aliquot of the preparation at an inverted light microscope. After 5 minutes the beker has been removed from the bath and the pancreas has been continually stirred with the aid of surgery sterile clamps up to when the digestion has achieved an appropriate level; at this point the tissue has been filtered on steel sieves, whose mesh measures respectively 400 and 90 μm, arranged in succession. The solution has been passed through the filters and the larger fragments held on the 400 μm filter have been put again in the beker for continuing the digestion. The tissue material held on the 90 μm filter has been recovered in a beker with a 2% HBSS solution of human albumin. The same procedure of filtering, washing and collecting in a HBSS solution has been repeated each 5 minutes for about 45 minutes or in any case up to full digestion of the organ. The main object of the following purification procedure was to separate the exocrine from the endocrine tissues. The HBSS volume collected has been aliquoted in 50 ml polypropylene conical test tubes and centrifuged at 250 g for 2 minutes at 4°C. The surnatant has been discarded and the pellet (approximately 1-2 ml) resuspended with 15 ml of a solution consisting of 80% Lymphoprep (Nycomed) and 20% HBSS. On the surface of the solution 10 ml of Hanks' s have been then stratified for creating a suitable density gradient. After centrifugation for 5 minutes at 909 rpm and 4⁰C, the islets were concentrated on the interface between the layer of Lymphoprep and the layer of HBSS where they have been recovered and again centrifuged for 2 minutes at 909 rpm and 4⁰C. At the end of the procedure, aliquots containing about 2500 islets have been suspended in 40 ml of a culture medium (M199 supplemented with 10% of bovine serum and antibiotics), loaded in plastic flasks for cellular cultures in suspension (75 cm², Iwaki) and put in the culture at 27⁰C in a CO₂ incubator (5% CO₂) . The culture medium has been changed a first time in the morning after the isolation in order to decelerate, by dilution, the action of collagenase, then weekly for renewing the essential components of the culture {Bugliani M, et al., Transplant Proc. 2004, 36 (3) : 605-6) .

Functional study

For the in vitro determination of the β-cellular functionality, the isolated islets have been subject to static incubation in Krebs-Ringer-bicarbonate-Hepes

(KRBH) solutions, supplemented with albumin 0.5% and glucose at the respective 3.3 mM and 16.7 mM concentrations and pH 7.4. Groups of islets of similar size have been transferred in 5 ml polypropylene test tubes (each experimental point has been measured three times) and preincubated for 45 minutes with a KRBH solution containing 3.3 mM glucose. After a quick washing operation the islets have been incubated for 45 minutes, always with 3.3 mM KRBH and glucose. From each test tube an aliquot of surnatant has been collected for computing the amount of insulin released in basal conditions. Then the same islets have been incubated for 45 minutes with 16.7 mM glucose or 10 μM glibenclamide (Gb) , 100 μM Gb, 10 μM 4-trans-hydroxy- glibenclamide (M-I) metabolite, 100 μM M-I, 10 μM DK315, 100 μM DK315. From each test tube an aliquot has been collected of surnatant for computing the amount of insulin released after stimulation. As described hereafter, the determination of insulinaemia is carried out with an IRMA method (Lupi R et al, Diabetes, 2002, 51 (5) ,1437-42; Marchetti P. et al., Diabetes, 2002, 51 (5) , 1419-24) .

Insulin dosage with IRMA method (ImmunoRadioMetric Assay)

As well known, the IRMA method is an immunoradiometric dosage based on the use of radioactively marked antibodies against the antigen that has to be determined. The assay provides test tubes with a bottom coated with anti insulin monoclonal antibodies. After the addition of the sample to measure, the system has been completed with the use of a tracing monoclonal antibody marked with

1125. After washing, a residual radioactivity of the test tube has reflected the antigen concentration

(Lupi R et al, Diabetes, 2002, 51 (5) , 1437-42) . Method

The procedure requires 2 days and the following operations are made in succession: 1^st Day The samples are maintained at 4⁰C the day before the test.

2^nd Day

The standards provided with the kit have been reconstituted with the addition of suitable volumes of milliQ water and put in a vortex. In the test tubes, previously numbered, 50 μl of standard or of sample have been dispensed in double. Then, to each test tube 50 μl of tracing antibody (radioactive) have been added and after stirring the samples have been incubated for 2 hours at room temperature. At the end of the incubation 1 ml of a washing tampon has been added reconstituted with milliQ water. The liquid has been sucked with a vacuum pump and the washing step has been repeated for other two times with 2 ml of the washing tampon. The samples and the standards are arranged in increasing numerical succession in collectors of a gamma counter and each analysed for 60 seconds.

Functional study on the effect of M-I and DK315 in a model of vascular smooth muscle

In order to show a vasodilatory activity owing to the release of NO, the compounds have been tested on aorta ring slices, drawn from albine male mice of Wistar type (250-350 g) , respecting the European rules on animal experimentation (European Community Council Directive 86-609) .

The animals have been sacrificed by cervical dislocation, under light anaesthesia with ethyl ether. The thoracic portion of the aorta has been extirpated, precisely removing any connective and adipose tissue, and the endothelium has been removed mechanically, by means of rubbing the lumen of the artery with a syringe needle. Aorta rings of 5 mm have been put, with a 2 g preloading, in 20 ml baths for isolated organs and immersed in a solution of Tyrode (mM composition: NaCl 136.8; KCl 2.95; CaC12 1.80; MgSO4 7H2O 1.05; NaH2PO4 0.41; NaHCO3 11.9; Glucose 5.5), thermostated at 37 °C and continually bubbled with a O₂ (95%) and CO₂ (5%) gaseous mixture.

The tension developed by the smooth vascular muscle has been recorded through an isometric transducer (Grass FTO3) , connected to a computerised detecting and data analysing system (Bio-pac) . After an equilibrium period of 60 min, the removal of the endothelium has been verified by the supply of 10 microM acetylcholine in 30 mM KCl precontracted preparations. A vasodilatory effect of acetylcholine less than 10% with respect to the contraction induced by KCl has been considered as an acceptable removal index of the endothelium. The parts where a vasodilatory action has been observed larger than this limit have been discarded.

A) Concentration-vasodilatory response curves 40 min after the control of the endothelial removal, the preparations have been contracted with KCl (3OmM) and, at the plateau, increasing cumulative concentrations of M-I or DK315 (lnM-lOOμM) have been administered. Preliminary experiments have shown both the inefficiency of the vehicle (dimethylsulphoxide, DMSO) and the stability of the contraction induced by KCl (30 mM) for at least 60 min.

The same experimental protocol has been followed with preparations where, immediately after the control of the removal of the endothelium, ODQ 1 microM

(inhibitor of guanylate cyclase enzyme) has been incubated.

B) "Time-course" evaluation of the vasodilatory response.

40 min after the control of the endothelial removal, the preparation have been contracted with KCl (3OmM) and, at the plateau, a single concentration (1 microM) of M-I, of DK315 or of the sodium nitroprussiate reference drug (well known NO-donor) , has been administered. The vasodilatory effect has been observed for 50 min. Analysis of the data

The profile of the vasodilatory action has been expressed versus efficiency (Emax) and power (pIC50) .

Emax value represents the maximum vasodilatory response recorded in the concentration-response curves, expressed as % with respect to the contractile tone induced by the KCl (30 mM) . Parameter pIC50 represents a cologarithm of the molar concentration of the examined compound that is capable of inducing a vasodilatory response equal to 50% of the contractile tone caused by KCl (30 mM) and has been obtained from the S concentration-response curve, by means of a computerised calculation procedure (software: GraphPad Prism 3.0). The efficiency and power parameters are expressed as average ± standard error, obtained from 6 different experiments.

Secretagogue effect of insulin

Experiments have been preliminarily carried out with pancreatic islets of five donors, whose characteristic are given in table 1.

Table 1

In figures 1 and 3 of in the attached drawings the results are shown obtained from three different tests. The secrection results are expressed as stimulation index (IS) . This is the ratio between the amount of insulin released owing to a stimulus and the amount of insulin released in basal conditions. Then, the average values have been calculated for three different tests. These are given in tables 2 and 3 and are graphically shown in figures 2 and 4.

Table 2

Table 3

With reference to figure 1, the first group of histograms indicates the stimulation indexes of glucose (IS G) ; the second group the stimulation indexes are responsive to a low concentration glibenclamide (IS Glib 10 μM) ; the third group indicates the stimulation indexes in response to low concentration M-I metabolite (IS M-I 10 μM) ; the fourth group of histograms indicates the stimulation indexes in response to high concentration glibenclamide (IS Glib 100 μM) and finally the fifth group of histograms indicates the stimulation indexes in response to high concentration M-I metabolite (IS M-I 100 μM) . In figure 2 the averages of such experiments are shown.

With reference to figure 3, the first group of histograms indicates the stimulation indexes of glucose (IS G) ; the second group of histograms indicates the stimulation indexes in response to low concentration glibenclamide (IS Glib 10 μM) ; the third group of histograms indicates the stimulation indexes in response to a low concentration DK315 hybrid (IS DK315 10 μM) ; the fourth group of histograms indicates the stimulation indexes in response to high concentration glibenclamide (IS Glib 100 μM) . The fifth group of histograms indicates the stimulation indexes in response to the DK315 hybrid at high concentration (IS DK315 100 μM) . In figure 4 are shown the averages of such experiments. The data of this study indicate that, like glibenclamide, its metabolite 4-trans-hydroxy- glibenclamide (M-I) and the DK315 hybrid have similar insulin secretagogue effects. In particular, DK315 hybrid causes the release of insulin with an efficiency that is particularly evident at higher concentrations [100 μM] . Analysis of the NO-mediated vasodilatory effect

In figure 5 the concentration-vasodilatory response curves are shown for DK315, without (control, black squares) or in the presence of ODQ 1 μM (+ODQ, white squares) , a selective inhibitor of soluble guanylate cyclase (sGC) .

In the abscissa values, molar concentrations of the pharmaceutical composition are given as base 10 logarithms. In the ordinate values, the vasodilatory effect is expressed as % with respect to the pre- contraction induced by KCl 30 mM.

In particular, the DK315 compound causes a dose- dependent vasodilatory response showing a total efficiency (Emax = 100 in all the experiments) and a sub-micromolar power (pIC50 = 7.24 ± 0.012). The presence (1 μM) of ODQ has substantially completely suppressed the DK315 vasodilatory response. Since the NO vasodilatory action is responsive to its capacity of activating the guanylate cyclase enzyme, the fact that ODQ has suppressed the DK315 vasodilatory effect indicates that this compound causes the vasodilatory effect by releasing NO.

DK315 is therefore a molecule having pharmacodynamic NO-donor characteristic. At the tested concentration, the M-I compound has not shown significant vasodilatory effects.

"Time-course" evaluation of the vasodilatory response In figure 6 the vasodilatory response versus time is shown for DK315 (squares) and for a reference drug, sodium nitroprussiate (SNP) , (triangles) . In the abscissa values, the observation time in minutes is indicated. In the ordinate values, the vasodilatory effect is expressed as % with respect to the pre- contraction induced by 30 mM KCl. Both the drugs have been administered at a 1 μM concentration, at the time 0. At the 1 μM concentration, DK315 compound has caused a substantially full vasodilatory response that achieves the level maximum in about 30 min. The maximal induced response at this concentration is similar to that delivered by the sodium nitroprussiate reference drug (SNP) , however the comparison between the effects versus time of DK315 and of SNP shows that the vasodilation induced by DK315 can be correlated to a relatively slow NO release. DK315 can be considered therefore a "slow NO-donor". At the 1 μM concentration, the M-I compound has not induced a significant vasodilatory effect.

Claims

CLAIMS 1. Compound characterised in that it has an hypoglycemic action and it releases in the meantime nitric oxide (NO) , said compound having the following general formula (I) :

where at least one among R, Ri, and R₂ is a substitute comprising a nitroxy-ester group bound to an acyl aliphatic, or aromatic or aliphatic- aromatic group.

2. Compound, according to claim 1, wherein said substitute is shown by the formula (II) :

wherein:

~ X is selected from the group comprised of: a nitrogen atom, a CH,

~ R3 is selected from the group comprised of: a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an iso-propyl group, a propyl group, a butyl group, an iso-butyl group.

3. Compound, according to claim 1, wherein said substitute is shown by the formula (III) :

wherein :

— A is selected from the group comprised of : a methylene , a linear alkyl group ( C2-C4 ) , a branched group , in particular -CH ( CH3 ) , -CH ( CH₂- CH₃ ) , -CH ( iso-proρyl ) .

— X is selected from the group comprised of: a nitrogen atom, a CH,

— R3 is selected from the group comprised of: a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an iso-propyl group, a propyl group, a butyl group, an iso-butyl group.

4. Compound, according to claims 1, 2 or 3, wherein said substitute group of aliphatic nature or of formula (II) or (III) has cis- configuration with respect to the CH-NHCO- bond.

5. Compound, according to claims 1, 2 or 3, wherein said substitute group of aliphatic nature or of formula (II) or (III) has configuration trans- with respect to the CH-NHCO- bond.

6. Synthesis process of a compound according to claim 1 characterised in that it provides a condensation reaction between a hydroxylate derivative of a sulfonylurea and a carboxylic acid.

7. Process, according to claim 6, wherein said condensation reaction between said hydroxylate derivative of sulfonylurea and said carboxylic acid is carried out in the presence of dicyclohexylurea (DCC) and of a catalytic amount of 4-dimethylaminopyridine (DMAP) .

8. Process, according to claim 6, wherein said hydroxylate derivative of sulfonylurea is a hydroxylate compound on the cyclohexylic ring of glibenclamide .

9. Process, according to claim 8, wherein said hydroxylate compound on the cyclohexylic ring of glibenclamide is an active metabolite thereof selected from the group comprised of:

— 4-traΩS-hydroxyglibenclamide (M-I) ,

— 3-cis-hydroxyglibenclamide (M-2).

10. Pharmaceutical composition for treatment of diabetes mellitus of type 2 characterised in that it comprises a measured amount of at least one compound having general formula (I) according to claim 1.