Analytical Methods Development and Validation for Estimation of Fimasartan Potassium Trihydrate

Hypertensive heart disease refers to heart conditions caused by high blood pressure. A number of different heart disorders are caused by the heart working under increased Pressure. Hypertensive heart disease includes heart failure, thickening of the heart muscle, coronary artery disease, and other conditions.

Mainly two types:

1) Primary Hypertension: A disorder of unknown origin affecting the blood pressure regulating mechanism.

2) Secondary Hypertension: Secondary to other disease processes environmental factors, Stress, High sodium intake, Obesity and Smoking

Management Of Hypertension:

• Beta Adrenergic blockers: Propranolol, Metoprolol, Atenolol
• Alpha beta-Adrenergic blockers: Carvedilol sodium, Labetalol
• Alpha Adrenergic blockers: Prazosin, Terazosin
• Vasodilators: Minoxidil
• Angiotensin Renin inhibitors: Telmisartan, Olmesartan. Valsartan
• Angiotensin Converting enzyme inhibitors: Fosinopril, Lisinopril, Captopril
• Angiotensin II Receptor Antagonists: Irbesartan, Valsartan, Losartan, Fimasartan and Candesartan.
• Diuretics: Hydrochlorthiazide, Thiazide
• Calcium Channel Blockers: Clinidipine, Telodipine

Drug Profile of Fimasartan Potassium Trihydrate ^[1-7]

MATERIALS AND METHODS

MATERIALS

• Fimasartan potassium trihydrate
• Methanol and All other chemicals used were of analytical reagent grade.

Instrumentation

UV Spectrophotometric method was performed on Shimadzu UV Visible double beam (1800) spectroscopy. UV Probe software was used for all absorbance measurements.

Identification By Melting Point Determination:

Melting point of Fimasartan potassium trihydrate determined by open capillary method using Melting point apparatus in which the drug was filled in the capillary tubes and were kept in the Melting point apparatus which shows the melting range of Fimasartan potassium trihydrate. Repeat the method for three times consequently and report the result. The Reported Melting point and Observed Melting point of Fimasartan potassium trihydrate showed in Table 2.

Table 2: Melting point of Fimasartan potassium trihydrate

Identification By Solubility Determination:

The Solubility study of Fimasartan potassium trihydrate  were determined by taking 10 mg of  drug in 10 ml of volumetric flask separately, and add the required quantity of solvent for complete solubility. Observe the solubility. The solubility of Fimasartan potassium trihydrate  was showed in Table 3.

Table 3: Solubility of Fimasartan Potassium trihydrate

Identification By IR Spectral Determination:

1. Fimasartan potassium trihydrate:

• IR spectra of drug was obtained by IR Spectrophotometer. Required quantities of drugs were kept directly in the sample in the sample compartment of IR and they were scanned in the range 400-4000 cm^-1. IR spectra of drug was interpreted.
• Interpretation data of Fimasartan potassium trihydrate was mentioned in Table 4.

Figure 1: Fimasartan potassium trihydrate Sample IR spectra of API

Table 4: Interpretation of IR Spectra of Fimasartan potassium trihydrate ^[8]

Identification By UV Spectrophotometric Method:

• Take 1 ml of Fimasartan potassium trihydrate from the standard stock solution of 100 µg/ml respectively to prepare 10 µg /ml of Fimasartan potassium trihydrate  respectively, Observe absorbance by UV Spectrophotometric method.
• UV Spectra of Fimasartan potassium trihydrate showed in Figure 2 and Observed and Reported Wavelength mentioned in Table 5.

Table 5: Wavelength of Fimasartan potassium trihydrate

Figure 2: UV Spectrum of Fimasartan potassium trihydrate (10 ug/ml) at  265 nm

Fimasartan potassium trihydrate:

Preparation of standard stock solution of Fimasartan potassium trihydrate (100 µg/ml): Weighted accurately 10 mg of Fimasartan Potassium trihydrate and transferred it into a 100 ml volumetric flask and dissolved with methanol and diluted up to the mark to obtain a standard stock solution (100 µg/ml).

Procedure for determination of wavelength for measurement:

1 ml of working standard stock solution of Fimasartan potassium trihydrate (100 µg/ml) were pipette out in 10 ml volumetric flask and volume was adjusted to the mark with methanol to get 10 µg/ml of  Fimasartan potassium trihydrate

Each solution was scanned between 200-400 nm against Methanol as a reagent blank.  Wavelengths were selected from the overlay spectra of Fimasartan potassium trihydrate

Preparation of calibration curves:

Calibration Curve for Fimasartan Potassium trihydrate (5-25 µg/ml):

An Aliquots of stock solution of Fimasartan potassium trihydrate (100 µg/ml) 0.5, 1.0, 1.5, 2.0 and 2.5 ml was pipette out in 5 different 10 ml volumetric flask and made up to mark with methanol which will give 5, 10, 15, 20 and 25 µg/ml respectively.

Absorbance of each solution was measured at 265 nm using methanol as blank. Graph of Absorbance vs. Concentration was plotted.

Method Validation ^[9]

Linearity & Range (n=6)

The linearity of Fimasartan potassium trihydrate was taken to be in the range of 5-25 µg/ml respectively. Calibration curve of absorbance vs concentration was plotted and from that slop, intercept, correlation coefficient and regression line equation for Fimasartan potassium trihydrate was constructed.  Linearity data for Fimasartan potassium trihydrate at 265 nm are recorded.

Precision:

The precision of an analytical procedure expresses the closeness of agreement (degree of scatter) between a series of measurements obtained from multiple sampling of the same homogeneous sample under the prescribed conditions. Precision may be considered at three levels: Intermediate (Intraday) precision, reproducibility (Interday precision), repeatability.

Intraday precision (n=3)

Solution containing Fimasartan potassium trihydrate 5, 10 and 15 µg/ml were analyzed three times on the same day and % RSD was Calculated.

Interday precision (n=3):

Solution containing 5, 10 and 15 µg/ml of Fimasartan potassium trihydrate were analyzed three different successive days and % RSD was Calculated.

Repeatability (n=6):

Solution containing 10 µg/ml of Fimasartan potassium trihydrate were analyzed for six times and % RSD was calculated. RSD was not more than 2%.

Accuracy (n=3):

The accuracy of an analytical procedure expresses the closeness of agreement between the value which is accepted either as a conventional true value or an accepted reference value and the value found. Accuracy of the developed method was confirmed by doing recovery study as per ICH guideline at three different conclusion levels 50 %, 100 % and 150 % and the values were measured at all wavelengths for Fimasartan potassium trihydrate .

Limit of Detection (LOD):

Limit of Detection can be calculated using following equations as per ICH guidelines.

LOD = 3.3 × (σ /S)

Where, sigma = standard deviation of the Y intercept of Calibration curve

S = Mean slope of the corresponding Calibration Curve.

Limit of Quantification (LOQ):

Limit if Quantification can be calculated using following equations as per ICH guideline.

LOQ = 10 × (σ/S)

Where, sigma = standard deviation of the Y intercept of Calibration curve

S = Mean slope of the corresponding calibration curve.

RESULTS AND DISCUSSION:

Selection of Wavelength for Fimasartan Potassium Trihydrate

To determine the wavelength for measurement, Fimasartan Potassium trihydrate (10 µg/ml ) solutions were scanned between 400 – 200 nm. Absorbance maxima were obtained at their Wavelength max 265 nm for Fimasartan potassium trihydrate, respectively. There Wavelength was used for all measurement (Figure 3).

Figure 3: Linearity spectra for Fimasartan potassium trihydrate (5-25 µg/ml) at 265 nm in Methanol

Linearity Of Fimasartan Potassium Trihydrate:

• The linearity of Fimasartan potassium trihydrate was taken to be in the concentration range of 5-25 µg/ml, respectively (Linearity spectra of Fimasartan potassium trihydrate  fig.3).
• The % RSD of Fimasartan potassium trihydrate at 265 nm was found to be 0.49%-0.78% , respectively. (Table 6).
• The calibration curves of Fimasartan potassium trihydrate 265 nm showed in fig. 4 and found R² value 0.9998 , respectively.

Figure 4: Calibration curve for Fimasartan Potassium trihydrate at 265 nm in Methanol

Precision Of Fimasartan Potassium Trihydrate:

• The % RSD of Fimasartan potassium trihydrate for Intraday precision at 265 nm was found to be 0.31% - 0.45% , respectively.
• The % RSD of Fimasartan potassium trihydrate for Interday precision at 265 nm was found to be 0.72%-1.18%, respectively.
• The % RSD of Fimasartan potassium trihydrate for Repeatability at 265 nm was found to be 1.32% respectively.
• The Precision data for Intraday, Interday and Repeatability of Fimasartan Potassium trihydrate showed in Table 7 respectively.

Table 7: Precision study of Fimasartan potassium trihydrate at 265 nm

LOD AND LOQ of Fimasartan Potassium Trihydrate:

• The LOD and LOQ of Fimasartan potassium trihydrate at 265 nm was found to be   0.49 µg/ml and 1.50 µg/ml, respectively.
• All the results of LOD and LOQ were showed in Table 8.

Table 8: LOD and LOQ data for Fimasartan potassium trihydrate for estimation method

Analysis Of Pharmaceutical Dosage Form:

The % assay of Fimasartan potassium trihydrate was found to be 99.82% respectively. The results were showed in Table 9.

Table 9: Analysis of Fimasartan potassium trihydrate in Pharmaceutical Dosage Form