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graphis capsules from 17 manufacturers were then conducted using 50% methanol in order

assayed for their andrographolide contents to avoid andrographolide peak shape pro-
using the optimized ultrasonication condition blem. The effect of sonication time was shown
and reflux extraction method. Each sample in Table 1. The results showed that the

was extracted in duplicate. The percentage amount of drug extracted increased with the
change in the andrographolide content was time of sonication, reaching a maximum at
calculated using the result from reflux extrac- 15 minutes for most of the samples tested.

tion method as reference. The sonication time of 15 minutes was then
taken as the best condition for comparing
Results with the reflux method which is a standard

preparation method described in the THP.
1. Optimization of extracting solvent and
sonication time 2. Method validation

Peak shape problem of andrographolide Under the described conditions, no peak

peak was clearly observed when 100% metha- interferences were found at the retention time
nol was used as the solvent of sample solu- of andrographolide in the samples prepared
tions. There is no further investigation on the from both reflux extraction and ultrasonication.

effect of sonication time of this extracting Chromatograms of sample solutions obtained
solvent. Optimization of sonication time was from the two different extraction techniques

Table 1 Effect of sonication time on andrographolide content extracted (%w/w)

Sample Content of andrographolide extracted (%w/w)
No. Sonication time (minutes)
5 10 15 20 25
1 1.97 1.86 1.99 1.93 1.95
2 0.85 0.86 0.87 0.86 0.86
3 1.66 1.66 1.67 1.66 1.66
4 2.86 2.90 2.88 2.87 2.87
5 1.79 1.85 1.91 1.80 1.89
6 3.91 3.94 3.95 3.95 3.99
7 3.57 3.51 3.57 3.56 3.54
8 2.39 2.39 2.52 2.39 2.48
9 1.93 2.08 2.07 2.12 2.08
10 0.72 0.78 0.76 0.75 0.76