Abstract
This study aimed to simultaneously quantify the concentration of herbal and inorganic active pharmaceutical
ingredients in suspensions for dental caries prevention by using near-infrared spectroscopy. Fifteen suspensions
containing various concentrations of active pharmaceutical ingredients, i.e. α-mangostin and calcium phosphate
containing silver ion, were prepared. The near-infrared spectrum of each suspension was measured and correlated
with concentrations of active pharmaceutical ingredients by partial least square regression. The predicted
results from various pre-treatments were compared to obtain the best calibration model, and was validated with
the external validation data set. The equation and correlation coefficient value for the prediction of α-mangostin
concentration were y = 0.8983x - 0.0184 and 0.8988, respectively. The equation and correlation coefficient value
for the prediction of concentration of calcium phosphate containing silver ion were y = 0.9732x + 0.0346 and
0.9672, respectively. The results showed that near-infrared spectroscopy could predict the concentrations of both
active pharmaceutical ingredients in suspensions with sufficient accuracy. It could be a useful tool for the quantitative
analysis of the oral care suspensions containing the mixing of herbal and inorganic medicine.
