Ethanol bromocriptine

Bromocriptine 2 (0.65 g, 1 mmol) was dissolved in 100 ml of dry ethanol and 60 ml of tetrafluoroboric acid / diethylether complex (85 %) was added while stirring. After standing overnight at RT the solvent was evaporated and the raw product isolated by extraction in the system dichloromethane 12% ammonia in water and evaporated to the dry residue. This residue was applied to the chromatographic column (I.D. = 2 cm, lenght = 20 cm) packed with silicagel and eluted with dichloromethane / ethylacetate =1 1. The fractions containing 2 were evaporated to the dry residue and crystallized from alcohol. 

Bromocriptine mesilate exhibits fluorescence like the other lysergic and isolysergic acid type alcaloids. In 2 percent ethanolic tartaric acid solution, the emission maximum appears at 402 nm (excitation at 325 nm). See fig. 3. 

Fluorescence Spectrum of Bromocriptine Mesilate in 2 % Ethanolic Tartaric Acid. C = 65yt g/ml. 

The identity of methanesulphonic acid may be determined by tic on cellulose plates, Merck no. 5728, with ethanol/ water/conc. ammonia 80 16 4 (v/v/v) as a mobile phase. Detection is achieved by spraying with acid-base indicators, e.g. bromocresol green or similar species. Rf of methanesulphonic acid is 0.5 (that of bromocriptine base = 0.9). 

Bromocriptine can also be identified as the base by ir spectroscopy after extraction from the dosage form with ethanol and removal of the solvent, both in solution and in a KBr pellet (33). ... 

A specific assay of bromocriptine mesilate in the dosage form may be carried out by tic followed by uv-spectrophotometry (26)(The system can also serve for identification purposes). The drug substance is extracted with methanol in the absence of light, the chromatographic conditions are Merck plates F 254, mobile phase dichloromethane/dioxane/ ethanol abs./conc. ammonia 180 15 5 0.1 per volume. 

Engleman EA, McBride WJ, Li TK, Lumeng L, Murphy JM (2003) Ethanol drinking experience attenuates (—)sulpiride-induced increases in extracellular dopamine levels in the nucleus ac-cumbens of alcohol-preferring (P) rats. Alcohol Clin Exp Res 27 424-31 Ennis C, Kemp JD, Cox B (1981) Characterisation of inhibitory 5-hydroxytryptamine receptors that modulate dopamine release in the striatum. J Neurochem 36 1515-20 Ensinger H, Majewski H, Hedler L, Starke K (1985) Neuronal and postjunctional components in the blood pressure effects of dopamine and bromocriptine in rabbits. J Pharmacol Exp Ther 234 681-90... 

The interpretation of the mechanism of the influence of neuroleptics on ethanol reinforcement and the appraisal of the precise role of DA is complicated by the fact that DA receptor agonists either direct (e.g. bromocriptine) or indirect (e.g. amphetamine), similarly to neuroleptics, reduce ethanol drinking (Samson et al., 1993). 

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