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Abstract

A rapid quantitative, enantioselective HPLC method for the analysis of the four stereoisomers, (+) and (-) erythro and (+) and (-) threo forms, of mefloquine has been developed using a Chiralpak Ad analytical column containing amylose tris-3,5-dimethylphenyl carbonate coated on silica gel and hexane/ethanol/diethylamine (96:4:0.1, v/v%) as the mobile phase. This method made it possible to quantitate small amounts of threo form in the presence of the erythro form of mefloquine, the form which is used as the active ingredient in commercial mefloquine tablets. Tablets from three sources were studied to estimate their optical purity, and it was found that tablets from one source contain 0.27 w/w% of the (-)-threo and 0.25 w/w% of the (+)-threo form, tablets from the second source contain 0.056 and 0.042 w/w% (-)- and (+)-threo, respectively, and tablets from the third source contain 0.052 w/w% (+)-threo, with the remainder erythro.

Liquid-phase microextraction combined with high-performance liquid chromatography for the enantioselective analysis of mefloquine in plasma samples

“…The mobile phase used for the analysis of MQ consisted of hexane-ethanol (97:3, v/v), plus diethylamine (0.05%), at a flow rate of 1 ml/min. Enantiomeric elution order was evaluated by analyzing pure enantiomers (obtained by semipreparative analysis under the conditions established) using a procedure described in Qiu et al [13].…”

“…There are some indirect methods reported for the enantioseparation of MQ using (−)-1-(9-fluorenyl)ethyl chloroformate and (+)-(S)-naphthylethylisocyanate as chiral derivatizing reagents [11,12]. In addition, some direct methods based on chiral stationary phases were also reported [13,14]. More recently, an electrophoretic method was developed to resolve MQ enantiomers [15].…”

Trapped in Misbelief for Almost 40 Years: Selective Synthesis of the Four Stereoisomers of Mefloquine

“…The e.r. of the final products 1 a (e.r.=96:4), 1 b (e.r.=96:4), ent ‐ 1 a (e.r.=94:6) and ent ‐ 1 b (e.r.=93:7) has also been checked by means of chiral HPLC27 and did not change significantly during the synthetic pathway relative to 7 ( ent ‐ 7 ) as well as 12 ( ent ‐ 12 ).…”

The Absolute Configuration of (+)‐ and (−)‐erythro‐Mefloquine

“…For the (+)‐ erythro ‐enantiomer we obtained very similar [ α ] D values as reported previously 11. For comparison with reported HPLC data, the hydrochloride was converted into the free base 12. The synthesis of the Mosher amide derivatives was achieved with (+)‐ erythro ‐mefloquine as well as the racemate using five equivalents of Hünig’s base ( i Pr 2 NEt) and ( S )‐MTPA‐Cl as well as ( R )‐MTPA‐Cl, respectively 13.…”