Ephedrine/Pseudoephedrine HCl in Oral Solution Analysis
Dean Duan
Merck China Application Lab Shanghai, China
Chinese Pharmacopeia Method
Ephedrine hydrochloride and pseudoephedrine hydrochloride can be used to reduce cold, allergic rhinitis, rhinitis and sinusitis caused by nasal congestion symptoms and control bronchial asthma. The same compounds are also found in the Chinese traditional medicine Xiao’er Kechuanling oral solution.
This application focuses on the determination of ephedrine HCl and pseudoephedrine HCl. Oral solution samples were distilled to extract the ephedrine HCl and pseudoephedrine HCl. Samples were then filtered through Millex® PTFE syringe filters, prior to HPLC-UV analysis using a Purospher® STAR RP-18 endcapped HPLC column.
The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.04 µg/kg and 0.12 µg/kg, respectively, for ephedrine, and 0.02 µg/kg and 0.06 µg/kg, respectively, for pseudoephedrine. The method can be used for determination of ephedrine HCl and pseudoephedrine HCl in Xiao’er Kechuanling oral solution.
Figure 1.Chemical structures of compounds used in the study.
Determination of Ephedrine HCl and Pseudoephedrine HCl in Xiao’er Kechuanling Oral Solution
Purospher® STAR RP-18e
| Experimental Conditions | |
|---|---|
| Column Used: | Purospher® STAR RP-18e 250 x 4.6 mm, 5 µm (1.51456.0001) |
| Detection: | Waters e2695, 210 nm |
| Mobile phase A: | 10 mM KH2PO4, adjust pH value to 2.3 with H3PO4 |
| Mobile phase B: | Methanol |
| Gradient: | A : B = 89 : 11, v/v |
| Flow Rate: | 1.0 mL/min |
| Injection Volume: | 20 µL |
| Temp: | 30 °C |
| Standard | Dissolve appropriate amount of ephedrine HCl and pseudoephedrine HCl in mobile phase to obtain a solution containing 5 µg/mL of ephedrine HCl and 3 µg/mL of pseudoephedrine HCl |
| Sample: | Accurately weigh 5 mL of oral solution into a 500-mL round-bottomed flask, add into 120 mL of 10% sodiμm hydroxide, shake well, distill, collect ~95 mL distillate into a 100-mL volμmetric flask containing 5 mL of 10 mM of 10 mM KH2PO4 (adjust pH value to 2.3 with H3PO4). Make up to the tick mark with water. Filter with 0.45 µm filter membrane |
| Pressure drop: | 2150 psi |
Figure 2.Chromatogram of ephedrine HCl and pseudoephedrine HCl standard solution.
Figure 3.Chromatogram of in Xiao’er Kechuanling oral solution.
Figure 4.Chromatogram of solvent blank.
| No | Compound | Retention Time (min) | Resolution | Theoretical Plates | Tailing Factor |
|---|---|---|---|---|---|
| 1 | ephedrine HCl | 18.2 | -- | 9698 | 1.1 |
| 2 | pseudoephedrine HCl | 20.0 | 2.4 | 10292 | 1.1 |
Specificity and Repeatability – Ephedrine and Pseudoephedrine
Specificity: Inject reference solution and determine the retention time of desired analyte in presence of other components like impurities. | |||||
|---|---|---|---|---|---|
| No | Compound | Retention Time (min) | Area (%) | Tailing Factor | RRT |
| 1 | ephedrine HCl | 18.2 | 56.4 | 1.1 | 1.0 |
| 2 | pseudoephedrine HCl | 20.0 | 32.8 | 1.1 | 1.1 |
| Standard repeatability (5 µg/mL) - ephedrine HCl | |
|---|---|
| STD 1 | 212571 |
| STD 2 | 227584 |
| STD 3 | 215716 |
| STD 4 | 212961 |
| STD 5 | 251431 |
| Mean | 1547859 |
| Standard Deviation | 16480.3 |
| RSD (%) | 1.1 |
| Standard Repeatability (5 µg/mL) - Pseudoephedrine HCl | |
|---|---|
| STD 1 | 123655 |
| STD 2 | 123017 |
| STD 3 | 126350 |
| STD 4 | 122884 |
| STD 5 | 133801 |
| Mean | 1327102 |
| Standard Deviation | 4611.6 |
| RSD (%) | 0.3 |
Calibration Data - Ephedrine
Linearity (area mAU*min), ephedrine HCl | |
|---|---|
| Conc. (µg/mL) | Mean Area |
| 0.10 | 3380 |
| 0.20 | 8013 |
| 0.40 | 16834 |
| 0.5 | 20141 |
| 1.0 | 35864 |
| 2.0 | 79213 |
| 4.0 | 166302 |
| 5.0 | 212571 |
| 6.0 | 272766 |
LOD and LOQ, ephedrine HCl | |
|---|---|
| Conc. (µg/mL) | Mean Area (mAU*min) |
| 0.10 | 3380 |
| 0.20 | 8013 |
| 0.40 | 16834 |
| 0.50 | 20141 |
| STEYEX | 508.2 |
| Slope | 42344.5 |
| LOD (ppm) | 0.04 |
| LOQ (ppm) | 0.12 |
Figure 5.Calibration curve of ephedrine HCl.
Calibration Data - Pseudoephedrin
Linearity (area mAU*min), pseudoephedrine HCl | |
|---|---|
| Conc. (µg/mL) | Mean Area |
| 0.06 | 1976 |
| 0.12 | 4684 |
| 0.24 | 8952 |
| 0.30 | 11653 |
| 0.60 | 19605 |
| 1.2 | 45571 |
| 2.4 | 98038 |
| 3.0 | 123655 |
| 4.0 | 179102 |
4.2 LOD and LOQ - pseudoephedrine HCl | |
|---|---|
| Conc. (µg/mL) | Mean Area (mAU*min) |
| 0.06 | 1976 |
| 0.12 | 4684 |
| 0.24 | 8952 |
| 0.30 | 11653 |
| STEYEX | 255.2 |
| Slope | 39369.9 |
| LOD (ppm) | 0.02 |
| LOQ (ppm) | 0.06 |
Figure 6.Calibration curve of pseudoephedrine HCl.
Conclusion
The method can be used for ephedrine HCl and pseudoephedrine HCl in Xiao’er Kechuanling oral solution.
如要继续阅读，请登录或创建帐户。
暂无帐户？
