HPTLC-Based Estimation of Fimasartan Potassium Trihydrate: Method Development and Validation in Bulk and Tablet Formulations

Hypertension is defined as a persistent rise in blood pressure (≥140/90 mmHg). This is the point at which there is a substantial increase in the risk of cardiovascular problems associated with hypertension and the need for medical intervention. Hypertension is one of the most common cardiovascular conditions worldwide. In India, over 29.8% of the population suffers from high blood pressure. [1] To reduce blood pressure, Fimasartan Potassium Trihydrate, a contemporary angiotensin II receptor antagonist (ARB), selectively targets AT1 receptors. According to its chemical identity, it is potassium 5-[4?-({2-butyl-5-[(dimethylcarbamothioyl)methyl]-4-methyl-6-oxo-1,6-dihydropyrimidin-1-yl} methyl)-[1,1?-biphenyl: -2-yl] The trihydrate of -1H-1,2,3,4-tetrazole-1(fig.1).[2] This medication is frequently used for mild-to-moderate essential hypertension and is known to dissolve well in methanol and acetonitrile. The terminal half-life of elimination is seven to ten hours, and it is rapidly absorbed when administered orally, reaching maximum plasma levels between 0.5 and 3 hours. [3] A thorough review of the literature showed that a number of analytical and bioanalytical techniques, such as UV [4], HPLC [5–12], and LC-MS [13–16], have been described for Fimasartan Potassium Trihydrate. To the best of our knowledge, no straightforward and affordable HPTLC technique has been developed for estimating it in tablet and bulk formulations. Therefore, in accordance with the ICH Q2(R1) criteria, the study aimed to design and validate a straightforward, sensitive, rapid, accurate, and economical HPTLC technique for the estimation of Fimasartan Potassium Trihydrate in bulk and pharmaceutical formulations.

Fig. 1. Molecular structure of Fimasartan Potassium Trihydrate

Experimental

Chemicals and Reagents

A pure sample of Fimasartan Potassium Trihydrate was kindly provided by MacLeod’s Pharmaceuticals Pvt. Ltd. (Mumbai, India). Fimanta tablets were purchased from a local pharmacy in India. HPLC-grade chloroform was obtained from Rankem (India), and analytical-grade methanol and glacial acetic acid (GAA) were used to prepare the mobile phase.

Chromatographic Setup and Instrumentation

The study was conducted using a CAMAG HPTLC system controlled by winCATS software (version 1.3.0) and included a Linomat V applicator, TLC scanner 3, and a 10 × 10 cm twin-trough chamber. Chromatography was performed using silica gel 60 F254 TLC plates that had been previously cleaned and activated. The proportions of carbon tetrachloride, methanol, and glacial acetic acid in the mobile phase were 8.5:1.5:0.2 by volume. The chemicals were identified at 261 nm after the chromatographic run was completed to a length of 8 cm.

Standard Stock Solution Preparation

To create a typical stock solution of Fimasartan Potassium Trihydrate (1000 µg/mL), 10 mg of the medication was precisely weighed, transferred to a volumetric flask with a capacity of 10 mL, dissolved in chloroform, and diluted to the appropriate level.

Study of Tablet Formulation

After weighing, 20 pills (10 mg each) were ground into a fine powder. After adding 10 mg of Fimasartan Potassium Trihydrate to a 10 mL volumetric flask with 7 mL of chloroform, the mixture was diluted after sonication for ten minutes. with chloroform to volume. The mixture was filtered, and chromatographic analysis was performed using a 0.9 µL aliquot containing 900 ng/band.

Method Validation

The method was extensively verified for linearity, accuracy, precision, robustness, ruggedness, specificity, and its detection and quantification limitations in accordance with ICH Q2(R1) criteria.

RESULTS WITH DISCUSSION

Optimization of Mobile Phase Composition

Several solvent systems were tested to achieve optimum separationA binary mobile phase consisting of methanol and carbon tetrachloride was first tested; however, it produced spot tailing. This problem was resolved by adding glacial acetic acid (GAA), which produced a symmetrical sharp peak. The best results were obtained with carbon tetrachloride: methanol: GAA (8.5:1.5:0.2 v/v/v) (fig. 2 and 3), producing an Rf value of 0.58 ± 0.02 for Fimasartan Potassium Trihydrate.

Linearity

To assess method linearity, a calibration curve was generated by plotting peak area versus concentration across the range of 300–1800 ng/band. A correlation coefficient of 0.998 indicated that the results were highly linear. Regression analysis revealed that Y = 6.4955x + 1590.4.

Table 1. Investigation of Fimasartan Potassium Trihydrate Linearity

Fig. 2. FPT HPTLC chromatogram, with Rf = 0.58 ± 0.02

Fig. 3. Linear Chromatogram of FPT

Precision

Precision was assessed through repeatability and intra- and inter-day studies. The %RSD values were below 2% in all cases, indicating a high precision. Repeatability at 900 ng/band yielded an RSD of 0.56%, while intra- and inter-day results ranged between 0.46% and 1.93%.

Table 2. [Intra-day and Inter-day] precision research

Table 3. Precision studies [Repeatability]

Accuracy

The accuracy was determined using recovery studies at 80%, 100%, and 120% of the target concentration. Recovery values ranging from 97.85% to 99.45% confirmed the high accuracy of the method. %RSD values were consistently below 1%.

Ruggedness

Ruggedness was assessed by examining samples at 900 ng/band by two different analysts. The %RSD values were below 2%, indicating the ruggedness of the method.

Fig. 4. A comparison of the FPT standard and tablet-extracted FPT peak purity spectra

Analysis of Tablet Formulation

The mean recovery was 99.22%, and the Fimasartan Potassium Trihydrate content in the commercial formulation ranged from 98.14% to 99.98%. Therefore, the analysis was not hampered by the excipients.