Resolution of (±)-ibuprofen using l-arginine-impregnated thin-layer chromatography

Direct enantiomeric resolution of some 2-arylpropionic acids using (−)-brucine-impregnated thin-layer chromatography

“…To account for this observation, the effect of temperature on enantiomeric resolution was investigated. It was observed that the best resolution for (AE)-ibuprofen was at 30 AE 2°C, as reported earlier (Bhushan and Parshad, 1996). In the present studies, (AE)-ibuprofen did not resolve at 35°C or 19°C, while at 24°C there was a poor resolution with elongated spots.…”

“…Castellani et al (1994), using HPLC and an ergot alkaloid-based stationary phase, proposed that enantioseparation of 2-arylpropionic acids such as (AE)-ibuprofen and (AE)-flurbiprofen was due to electrostatic and p-p interactions. Electrostatic interactions between the chiral selector and racemic compounds on impregnated TLC plates, resulting in in situ formation of diastereomers and thus resolution, has also been reported (Bhushan and Ali, 1987;Bhushan and Parshad, 1996).…”

“…(AE)-Ibuprofen has also been resolved using capillary electrophoresis (Fanali and Aturki, 1994). Enantioseparation of racemic ibuprofen using thin-layer plates impregnated with L-arginine as a chiral selector has already been reported from this laboratory (Bhushan and Parshad, 1996). Earlier, use of (À)-brucine as a chiral impregnating reagent to resolve DL-amino acids was reported (Bhushan and Ali, 1987).…”

On ups and downs by analysis of profen drugs. A mini review

“…An overview of this literature is given in a monograph [11], which clearly shows that, in spite of the well-recognized versatility and good performance of TLC, successful planar chromatographic enantioseparations are far from simple. In 2005, we decided to repeat the TLC procedure of enantioseparation with ibuprofen (one of the most popular profen drugs), first described in the literature by Bhushan and Parshad [12]. This procedure consisted of impregnating a silica gel layer with L-arginine as chiral selector and then enantioseparating on the pretreated thin layer the (±)-ibuprofen sample dissolved in 70% ethanol.…”

“…To this effect, we kept repeating each day (over the time span of a fortnight) the procedure described in Ref. [12], in all the experiments using one and the same (±) ibuprofen solution in 70% aqueous ethanol and one and the same (+)-ibuprofen solution as an external standard. To our utter surprise, as a result of the aging of the (+)-ibuprofen solution, we recorded striking irreproducibility of the retardation factor (R F ), which at fixed time intervals oscillated between the two extreme values, the difference (ΔR F ) between these two values highly exceeding the experimental TLC error (Fig.…”