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Journal of Chinese Pharmaceutical Sciences ›› 2017, Vol. 26 ›› Issue (3): 180-186.DOI: 10.5246/jcps.2017.03.018

• Original articles • Previous Articles     Next Articles

Preparation of the nanostructured lipid carriers of artemisinin and its pharmacokinetic evaluation

Hualing Dai, Weiqi Gao, Guoshun Zhang, Ruili Wang, Shuqiu Zhang*   

  1. Department of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
  • Received:2016-12-12 Revised:2017-02-18 Online:2017-03-30 Published:2017-03-07
  • Contact: Tel.: +86-0351-4690140, 13513629182, E-mail: shuqiu.zhang@126.com
  • Supported by:
    National Natural Science Foundation of China (Grant No. 81373364). The Subject clots Project Serving Pharmaceutical Industrial Innovation of Shanxi Province.

Abstract:

Artemisinin (ART) is a widely used active drug for malaria, including severe and cerebral malaria. However, its therapeutic efficacy is affected by its lower bioavailability. In the present study, nanostructured lipid carriers (NLCs) were proposed as carrier of ART to improve pharmacokinetic properties of the drug. ART-NLC was prepared by high-pressure homogenization based on orthogonal design. The particle size, zeta potential, encapsulation efficiency (EE) and percentage of drug loading (DL) of ART-NLC were (53.06±2.11) nm, (–28.7±3.59) mV, 73.9%±0.5% and 11.23%±0.37%, respectively. ART-NLC showed the sustained release characteristics and scarcely the hemolysis effect on human red blood cells. The pharmacokinetics of ART-NLC for rats after tail intravenous injection (i.v) or intraperitoneal injection (i.p) were investigated by liquid chromatography-tandem mass spectroscopy (LC-MS/MS). And ART solution was designed as control preparation. For rats of i.v groups, the AUC0–∞ ((707.45±145.65) ng·h/mL) of ART-NLC were significantly bigger than that of ART ((368.98±139.58) ng·h/mL). The MRT ((3.38±0.46) h) of ART-NLC was longer than that of ART ((1.39±0.61) h). And similar results were observed for rats of i.p groups. The AUC0–∞ ((1233.06±235.57) ng·h/mL) and MRT ((4.97±0.69) h) of ART-NLC were both bigger than those of ART, which were (871.17±234.03) ng·h/mL) and (1.75±0.31) h), respectively. Compared with ART, ART-NLC showed a significant increase in AUC0–∞ (P<0.05) and MRT (P<0.001) for both i.p and tail i.v administrations.

Key words: Artemisinin, Nanostructured lipid carriers, Pharmacokinetics, LC-MS/MS

CLC Number: 

Supporting:

 
Method validation
 
1. Chromatography specificity
    The specificity of the method was evaluated by analyzing six different blank samples of rat plasma (Fig. 5A); a blank rat plasma spiked with ART at LLOQ (Fig. 5B); a blank rat plasma spiked with IS (Fig. 5C); a blank rat plasma spiked with ART (Fig. 5D); a blank rat plasma spiked with ART and ARM (Fig. 5E); a rat plasma sample after injection of ART (Fig. 5F). It could be inferred from Fig. 5 that no interfering endogenous substances were detected at the retention time of ART and IS.
 
Figure 1. Representative MRM chromatograms.
 
2. Linearity and LLOQ
    The calibration curve could be constructed by plotting the peak-area ratios (y) of ART to IS versus the concentrations (x) of ART using weighed least squares linear regression (1/x2). The satisfying equation of calibration curve was obtained: y = 2.25 + 0.223 x, (r = 0.9990). The LLOQ of ART in rat plasma (n = 5) was established at 2.0 ng/mL equal to 10-fold of the ratio of signal-to-noise approximately (S/N =10).
 
3. Accuracy and precision
    The accuracy and precision of the method were assessed by determining QC samples (5, 250 and 320 ng/mL) using six replicated preparations of plasma samples on three separated days. The precision and the accuracy were expressed using relative standard deviation (RSD%) and the relative deviation (RE%), respectively. It was acceptable when the values of RE (%) and RSD (%) were less than 15% for the medium and high concentration, and 20% for the low concentration. The method was proved to be highly accurate with 97.6%-109.3% deviation from the nominal values, and highly precise with within-assay precision <4.5%, between-assay precision <12.0% at each concentration of QC sample tested.
 
4. Matrix effect and recovery
    The matrix effect was evaluated by comparing the peak areas obtained from ART spiked in the extracted blank plasma with those from ART solutions at concentrations of 5, 250 and 320 ng/mL, respectively. The way of assessing matrix effect of IS at 200 ng/mL was the same as ART. The matrix effect could be considered negligible when the ratios ranged from 85% to 115%. The extraction recovery of ART was investigated by comparing the peak areas of ART from QC samples with those from standard solutions without extration procedure at the same nominal concentrations. The recovery of IS was evaluated in a similar way at a work concentration of 200 ng/mL. The samples were performed in triplicate.
    The mean values of matrix effects of ART and IS were 89.63%±1.34% and 91.19%±3.98%, respectively, indicating that the ionizations of ART and IS were not affected by the matrix components in rat plasma. The mean values of recovery of ART and IS (89.29%±1.47% and 88.43%±3.11%, respectively) were all within the acceptable limits.
 
5. Stability
    The stability of ART was investigated by keeping the QC samples under all experienced conditions, including freezing/thawing over three cycles, autosampler vials at ambient temperature for 24 h, the freezer storage of ART in plasma at -20 °C for 4 weeks. All the QC samples for stability assessment were analyzed in triplicate. The results in Table 4 demonstrated that the plasma samples were stable under the above conditions.
 
Table 1. Stability of ART in rat plasma (n = 6).

Storage conditions
Concentration
Add (ng/mL)
Found (ng/mL)
RE (%)
RSD (%)
Three freeze/thaw cycles
5
5.21
104.2
6.9
250
245.58
98.2
1.8
320
315.29
98.5
7.2
-20 °C for 4 weeks
5
5.61
112.2
3.4
250
262.12
104.8
4.8
320
289.71
90.5
6.6
Treated samples at room temperature for 24 h
5
5.28
105.5
6.2
250
258.89
103.6
3.6
320
310.30
96.9
8.1