Figure 1
Analysis of THI and PYR in various pharmaceutical dosage forms – a) injection solutions Milgamma NA, b) film-coated tablets B-komplex Sanofi and c) capsules Diclovit. d) Illustrative electropherogram of THI and PYR at the concentration level 0.25 μg/mL. e) Illustrative electropherogram obtained from the CZE-UV analysis of non-spiked and spiked drug Diclovit. The spiked concentrations of THI and PYR were 5, 10 and 25 μg/mL. The injected volume was 200 nL.
Table 1
Performance parameters of the CZE-UV method.
| Thiamine | Pyridoxine | |
|---|---|---|
| tm (min) | 7.01 | 11.02 |
| RSDtm (%), n = 6 | 0.28 | 0.76 |
| RSDarea (%), n = 6 | 2.28 | 8.60 |
| a (mAU) | 134.76 | −39.09 |
| RSDa (%), n = 6 | 2.27 | 1.33 |
| b (mAU/μg mL) | 94.77 | 36.22 |
| RSDb (%), n = 6 | 0.49 | 0.29 |
| r2 | 0.9996 | 0.9990 |
| Linear range (μg/mL) | 0.5–100 | 1–100 |
| LOD (μg/mL) | 0.08 | 0.15 |
| LOQ (μg/mL) | 0.25 | 0.50 |
| N | 7900 | 6400 |
| R | 8.81 | |
[i] LOD and LOQ were calculated as the signal (S) to noise (N) ratios to be 3 × S/N and 10 × S/N, respectively. Separation efficiency (N) was calculated according to the equation N = 5.545*(tm/w1/2)2, where tm is the migration time and w1/2 is the full width at half maximum of the peak. The calibration curve is expressed by the equation y = b.x + a. RSDtm and RSDarea were calculated from the samples at LOQ concentration level. Resolution (R) was calculated according to the equation R = 1.18*(t2 – t1)/(w1/2 THI + w1/2 PYR), where t2 is the migration time of PYR, t1 is the migration time of THI, w1/2 THI is the full width at half maximum of the THI peak and w1/2 PYR is the full width at half maximum of the PYR peak.
Table 2
THI and PYR concentrations in three pharmaceutical samples determined by the CZE-UV method.
| Preparation | Parameters | |||
|---|---|---|---|---|
| Found ± SD (μg/mL) | RSD (%), n=3 | Declared (μg/mL) | ||
| Milgamma NA (inj) | THI | 53.15 ± 0.26 | 0.49 | 50 |
| PYR | 23.01 ± 0.23 | 0.98 | 25 | |
| Diclovit (cps) | THI | 50.81 ± 1.27 | 2.50 | 50 |
| PYR | 43.18 ± 1.07 | 2.48 | 50 | |
| B-komplex Sanofi (tbl flm) | THI | 11.59 ± 0.18 | 1.56 | 10 |
| PYR | 5.52 ± 0.50 | 9.00 | 5 | |