Enantiomeric purity
The enantiomeric purity is an important issue to produce pharmaceutical products of acceptable quality. The mobile phase was optimized to discriminate ESO and S-NAP from their chiral impurity (R-isomer). For checking the method ability to separate the chiral impurities from the active isomers of each drug, spiking of the prepared pure S-NAP and ESO isomers with their corresponding racemic mixtures at 1%, 2% and 5% levels of the main peak was done. Method optimization was done in order to achieve sufficient resolution and detecting the R isomer at low levels of the main peak, S isomer. This was done by spiking the pure S isomer of each drug (500 and 50 µg mL -1, for S-NAP and ESO respectively). The spiking was done using the prepared racemic solutions of each (5, 10 and 25 µg mL-1 of the racemic NAP and 0.5, 1 and 2.5 µg mL-1 of the racemic OME). As shown in figure 4, no interference from the chiral impurity was observed at 1% level of the main peak. The developed method was found efficient for determination of the enantiomeric purity of the drugs in pharmaceutical preparation. Good resolution between isomers, high detector sensitivity and baseline stability were essential for the detection of trace amounts of R isomers at a level of (1%) of the main peak. The high detector …show more content…
Placebo tablet (with no active ingredient) was processed in the same way described in sample tablet solution preparation (section 2.4). Then it was chromatographed under the same conditions described in section 2.2. The chromatogram of placebo was compared with that of the sample tablet (Fig. 5a) and standard drugs solutions. No interfering substances due to formulation excipients were eluted or interfered at the retention times of the drugs. Moreover, the DAD confirms the peak purity by recording the purity profiles and comparing the recorded plots of the sample tablet (Figs. 5b & 5c) with the
The enantiomeric purity is an important issue to produce pharmaceutical products of acceptable quality. The mobile phase was optimized to discriminate ESO and S-NAP from their chiral impurity (R-isomer). For checking the method ability to separate the chiral impurities from the active isomers of each drug, spiking of the prepared pure S-NAP and ESO isomers with their corresponding racemic mixtures at 1%, 2% and 5% levels of the main peak was done. Method optimization was done in order to achieve sufficient resolution and detecting the R isomer at low levels of the main peak, S isomer. This was done by spiking the pure S isomer of each drug (500 and 50 µg mL -1, for S-NAP and ESO respectively). The spiking was done using the prepared racemic solutions of each (5, 10 and 25 µg mL-1 of the racemic NAP and 0.5, 1 and 2.5 µg mL-1 of the racemic OME). As shown in figure 4, no interference from the chiral impurity was observed at 1% level of the main peak. The developed method was found efficient for determination of the enantiomeric purity of the drugs in pharmaceutical preparation. Good resolution between isomers, high detector sensitivity and baseline stability were essential for the detection of trace amounts of R isomers at a level of (1%) of the main peak. The high detector …show more content…
Placebo tablet (with no active ingredient) was processed in the same way described in sample tablet solution preparation (section 2.4). Then it was chromatographed under the same conditions described in section 2.2. The chromatogram of placebo was compared with that of the sample tablet (Fig. 5a) and standard drugs solutions. No interfering substances due to formulation excipients were eluted or interfered at the retention times of the drugs. Moreover, the DAD confirms the peak purity by recording the purity profiles and comparing the recorded plots of the sample tablet (Figs. 5b & 5c) with the