A tolbutamide-metformin salt based on antidiabetic drug combinations: synthesis, crystal structure analysis and pharmaceutical properties.

A drug-drug anhydrous pharmaceutical salt containing tolbutamide {systematic name: 3-butyl-1-[(4-methylbenzene)sulfonyl]urea, TOL, C12H18N2O3S} and metformin (systematic name: 1-carbamimidamido-N,N-dimethylmethanimidamide, MET, C4H11N5) was created based on antidiabetic drug combinations to overcome the poor pharmaceutical properties of the parent drugs. Proton transfer and the proportion of the two components were confirmed by 1H NMR spectroscopy and single-crystal X-ray diffraction analysis. Comprehensive characterization of the new pharmaceutical salt crystal, 2-[(dimethylamino)(iminiumyl)methyl]guanidine (butylcarbamoyl)[(4-methylbenzene)sulfonyl]azanide, C4H12N5+·C12H17N2O3S-, was performed and showed enhancement of the pharmaceutical properties, such as lower hygroscopicity and greater accelerated stability than the parent drug MET, and higher solubility and dissolution rate than TOL. The property alterations were correlated with the crystal packing features and potential hydrogen-bonding sites through observed changes in the crystal structures.

Mechanosynthesis of pharmaceutically relevant sulfonyl-(thio)ureas.

We demonstrate the first application of mechanochemistry to conduct the synthesis of sulfonyl-(thio)ureas, including known anti-diabetic drugs tolbutamide, chlorpropamide and glibenclamide, in good to excellent isolated yields by either stoichiometric base-assisted or copper-catalysed coupling of sulfonamides and iso(thio)cyanates.

Synthesis, antidiabetic and hypolipidemic activities of new diethylamine and triethoxysilyl derivatives of tolbutamide on rats.

Tolbutamide (N-[(butylamino)carbonyl]-4-methylbenzenesulfonamide, CAS 64-77-7, I) is the first generation of potassium channel blocker and sulfonylurea oral hypoglycemic drug that imparts marked blood glucose lowering effect in type 2 diabetes or non-insulin dependent diabetes mellitus (NIDDM) patients. In this study, I and its two new analogs with substituting butylamine side by 3-diethylamino-1-propylamine (3) and 3-triethoxysilyl-1-propylamine (4) were synthesized and their antidiabetic and hypolipidemic activities were evaluated applying known procedures, and compared with both I and glibenclamide (II, well known second-generation sulfonylurea antidiabetic drug). The results showed that these new drugs (III and IV) were more potent than I and II and it could be concluded that changing the amine side of I would produce more potentials in new drugs (III and IV) of the first generation, to be named as the third generation. Also investigations on hypoglycemic and lipid lowering effects of these drugs proved that IV could reduce glucose, triglyceride (TG) and a low density lipoprotein (VLDL) level in blood serum more than others (I-III), 16 days after STZ injection.

Synthesis and preliminary biological profile of new NO-donor tolbutamide analogues.

We describe a new class of NO-donor hypoglycemic products obtained by joining tolbutamide, a typical hypoglycemic sulfonylurea, with a NO-donor moiety through a hard link. As NO-donors we chose either furoxan (1,2,5-oxadiazole 2-oxide) derivatives or the classical nitrooxy function. A preliminary biological characterization of these compounds, including stimulation of insulin release from cultured rat pancreatic ß-cells and in vitro vasodilator and anti-aggregatory activities, is reported.

A new aspect of tolbutamide metabolism in the rabbit: the role of 1-butyl-3-(p-formylphenyl)sulphonylurea.

We investigated the metabolism of tolbutamide by using synthetic 1-butyl-3-(p-formylphenyl)sulphonylurea (ATB), an intermediate in the metabolic pathway of tolbutamide. ATB (40 mg kg-1) administered intravenously to rabbits was oxidized to 1-butyl-3-(p-carboxyphenyl)sulphonylurea (CTB) and also reduced to 1-butyl-3-(p-hydroxymethylphenyl)sulphonylurea (HMTB). Therefore, it is likely that in the metabolism of tolbutamide, the oxidation of HMTB to ATB involved the reverse reaction, suggesting the reduction of ATB to HMTB. The oxidation of ATB to CTB was inhibited by disulfiram pretreatment. ATB was detected in the blood following intravenous administration of HMTB in rabbits pretreated with disulfiram. These results, confirm that ATB is an intermediate in the oxidative metabolism of tolbutamide in the rabbit.