Besylate salt

Benzensulphonic salt of amlodipine was prepared as follows Amlodipine base (65.6 g, 0.161 mols) was slurried in industrial methylated spirit (denatured alcohol, 326.4 ml) and cooled to 5°C. Benzensulphonic acid (26.2 g, 0.168 mols) was dissolved in industrial methylated spirit (65.6 ml) at 5°C and added to base. The resulting slurry was then granulated, filtered and washed with 2 volumes the same solvent (65.6 ml). The damp solid was slurred at 5°C for 1 hr in 327.6 ml industrial methylated spirit, filtered, washed with 2 volumes of the same solvent (65.6 ml) and dried under vacuum at 55°C for 24 hr. A yield of besylate salt of amlodipine 65 g. 

The besylate salt of mesoridazine 43 is a commercially available antipsychotic medication that is used for treating schizophrenia and mania as well as major depression, anxiety, or severe behavior disorders in children. Mesoridazine 43 has four enantiomers, but the commercial samples are sold as only one diastereomeric pair. The methyl sulfoxide peak of 43 in the H NMR spectrum in the presence of 39 exhibits a peak for each of the four enantiomers. The areas of the sulfoxide resonances were used to compare the diastereomeric ratio of freshly prepared samples of 43 with commercial samples for changes in the ratio of the different isomers. ... 

Heparin and its salts are incompatible with many drugs including alteplase, amikacin sulfate, amiodarone hydrochloride, ampicillin sodium, aprotinin, benzylpenicillin potassium or sodium, cephalothin sodium, ciprofloxacin lactate, cytarabine, dacarbazine, daunorubicin hydrochloride, diazepam, dobutamine hydrochloride, doxorubicin hydrochloride, droperidol, erythromycin lactobionate, gentamicin sulfate, haloperidol lactate, hyaluronidase, hydrocortisone sodium succinate, kanamycin sulfate, methicillin sodium, netilmicin sulfate, some opioid analgesics, oxytetracycline hydrochloride, some phenothiazines, polymyxin B sulfate, streptomycin sulfate, tetracycline hydrochloride, tobramycin sulfate, vancomycin hydrochloride, vinblastine sulfate, cisatracurium besylate, labetalol hydrochloride, nicardipine hydrochloride, cefmetazole, sodium ions, and fat emulsion.110 112... 

Note Benzoate, besylate, and tosylate salts are examples of counter-ions that are sufficiently retained and should be included in the method development set. 

Quatemization can be done with several methylating reagents. However, since the product would be used parenterally, a soluble salt was necessary to dissolve the dose in a small volume. The usual methyliodide produced a salt of insufficient solubility. The more hydrophilic benzenesulfonate anion (besylate) proved to be satisfactory. 

Figure 8-15. Synthesis of atracurium besylate (benzene sulfonate salt). (From Stenlake, 1985.)...

A similar profile to nitrendipine of S > R plasma concentrations was observed for another dihydropyridine calcium channel blocker, amlodipine (Table 7). In a study employing 18 subjects, in which two salt forms (besylate and maleate) of amlodipine were administered (20 mg racemate), stereoselectivity was noted (Table 7) in the plasma S R AUC ratio for both... 

The derivatives of l,4-dUiydro-2,6-dimethylpyridines (1,4-DHP) are used for treatment of hypertension and regulation of blood pressure, acting as calcium channel modulators. The widely prescribed drugs are amlodipine (administered as a salt, the racemate) and felodipine (free base form). These two compounds, like most 1,4-DHPs, occur as R- and S-enantiomers because of an asymmetric substitution of ester groups (the chiral center is atom C4). Amlodipine besylate and felodipine have been studied by C CP MAS NMR and C1 NQR followed by DFT calculations. The methods did not differentiate between S- and R-enantiomers because of the symmetry of the 4-aryl ring comprising one (amlodipine) or two (felodipine) chlorine atoms oriented in a perpendicular fashion. 

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