Introduction: A combination of three active ingredients amlodipine besylate, telmisartan, and hydrochlorothiazide has been used and proven effective in the treatment of hypertension in patients with moderate to severe hypertension, while it contributes to a reduction in product costs and increases patient compliance. However, there are no monographs in pharmacopoeias for the simultaneous quantification of these three active ingredients. Therefore, in order to contribute to the establishment of an in-house specification for domestic generic drugs, shorten the time of quantifying each ingredient separately, the study was carried out with the aim of developing and validating procedure for the simultaneous quantification of amlodipine besylate, telmisartan, and hydrochlorothiazide by high performance liquid chromatography.

Methods: In this study, we conducted an investigation into different chromatographic conditions, developed an analytical procedure for the simultaneous quantification of amlodipine besylate, telmisartan, and hydrochlorothiazide in tablets preparation. The procedure was validated in compliance with ICH guidelines.

Results: Suitable chromatographic conditions for simultaneous quantification of amlodipine besylate, telmisartan, and hydrochlorothiazide are: Xterra C18 column (250 x 4.6 mm, 5 μm), detection wavelength 230 nm, gradient program of mobile phase: acetonitrile and phosphate buffer pH 3.0, flow rate 1.0 ml/min, sample injection volume 10 μl, column temperature 30°C. The procedure was validated for systematic suitability, accuracy, specificity, linearity, precision, working range, and robustness.

Conclusion: A procedure for the simultaneous quantification of amlodipine besylate, telmisartan, and hydrochlorothiazide in tablets by high performance liquid chromatography has been successfully developed and validated.

Methotrexate (MTX) is a chemotherapy and immunosuppressive agent widely used to treat cancer, autoimmune diseases in children and adult patients, and ectopic pregnancy. However, MTX is highly toxic to the liver, kidney, and nervous system. This study aimed to quantify the concentration of MTX in human plasma using high-performance liquid chromatography (HPLC). MTX and its internal standard (para aminoacetophenone-PAPA) in plasma samples were extracted simultaneously with methanol. Sample purity was performed using the 1 cc OASIS HLB cartridges. Sample injection volume of 10 µL was analyzed on a Lichrocart Supersil 125-4 column C18 maintained at 40 °C on a Waters 2695 XE equipped with a PDA detector set at 303 nm. The mobile phase contained phosphate buffer (pH 6.0) and methanol at a ratio of 80:20 (v/v) and was maintained at a flow rate of 1 ml/min. The results showed that the total time of chromatographic analysis was 15 min. MTX and PAAP were found in the chromatograms at retention times of 2.3 and 5.2 min, respectively. The linear range of the MTX from 0.5 to 25 µg/mL. Intra-day and inter-day imprecision for MTX ranged from 3.42 to 8.128%. LLOQ of MTX was 0.5 µg/mL and the extraction effects were above 77%. In conclusion, we developed and validated a simple HPLC method to determine the MTX concentrations in human plasma.
 

Curcuma aromatica, the herbal medicine belongs to Zingiberaceae family, is well known for anti-tumor activity through multiple pathways and a potential candidate for complementary medicine in cancer treatment. The aims of this study were to distinguish between Curcuma species based on polymorphisms of the nucleotide sequence of chloroplast DNA (cpDNA) and preliminarily analyze their potential-anticancer compounds. Totally six samples supposed C. aromatica growing in An Giang province, Vietnam were collected. The contents of curcumin, curdione, and germacrone in the six samples were analyzed and compared by using the high-performance liquid chromatography (HPLC) method. All specimens were identified according to their trnSfMintergenic spacer sequences by Sanger sequencing. Among the six samples, three were determined as C. aromatica, two were C. longa, and one was C. zedoaria. Curcumin, curdione, and germacrone, known as anticancer compounds, were simultaneously found in sample NT3 that identified as C. aromatica by Sanger sequencing. The obtained results revealed a potential herbal candidate for complementary and alternative medicine.