Telmisartan

Telmisartan is an angiotensin-II receptor antagonist (ARB) used in the treatment of hypertension. Generally, angiotensin-II receptor blockers such as telmisartan bind to the angiotensin-II type 1 receptors with high affinity, causing inhibition of the action of angiotensin II on vascular smooth muscle, ultimately leading to a reduction in arterial blood pressure. The present study gives a comprehensive profile of telmisartan, including detailed nomenclature, formulae, elemental analysis, and appearance of the drug are mentioned. The uses and applications and the several methods described for its preparation of the drug are outlined. The profile contains the physicochemical properties including: pKa value, solubility, X-ray powder diffraction, melting point, and methods of analysis (including compendial, electrochemical, spectroscopic, and chromatographic methods of analysis). Developed validated stability-indicating (HPLC and biodiffusion assay methods under accelerated acidic, alkaline, and oxidative conditions, in addition to effect of different types of light, temperature, and pH. Detailed Pharmacology also presented (Pharmacological actions, Therapeutic uses and Dosing, Interactions, and adverse effects and precautions). More than 80 references were given as a proof of the above-mentioned studies.

Absorbance correction method for estimation of telmisartan and metoprolol succinate in combined tablet dosage forms

Aim and Background:

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of telmisartan and metoprolol succinate in combined tablet dosage form.

Materials and Methods:

The method is based on the absorbance correction equations for analysis of both the drugs using methanol as solvent. Telmisartan has absorbance maxima at 296 nm and metoprolol succinate has absorbance maxima at 223 nm in methanol. The linearity was obtained in the concentration range of 2-16 μg/ ml and 3-24 μg/ml for telmisartan and metoprolol succinate, respectively. The concentrations of the drugs were determined by using absorbance correction method at both the wavelengths. The method was successfully applied to pharmaceutical dosage form because no interference from the tablet excipients was found. The suitability of this method for the quantitative determination of telmisartan and metoprolol succinate was proved by validation. The proposed method was found to be simple and sensitive for the quality control application of telmisartan and metoprolol succinate in pharmaceutical dosage form.

Result:

The result of analysis has been validated statistically and by recovery studies. Recoveries were found in the range of 98.08-100.55% of telmisartan and 98.41-101.87% of metoprolol succinate.

Stress degradation studies on Telmisartan and development of a validated method by UV spectrophotometry in bulk and pharmaceutical dosage forms

Aim and Background:

To develop and validate a simple, precise, accurate, and stability indicating a UV-method for estimation of Telmisartan (TELM). UV, HPLC, HPTLC, and many more experiments were carried out by taking single drug and also by combining with other drugs. However, Such type of studies was not reported.

Materials and Methods:

In both methods, TELM has the absorbance maxima at 296 nm. Method A involves method development and validation and Method B involves forced degradation study. In these methods, methanol was used as a solvent. Linearity was observed in the concentration range of 4–16 μg/ml. Validation experiments were performed to demonstrate system suitability, specificity, precision, linearity, accuracy, robustness, LOD, and LOQ as per International Conference on Harmonization guidelines. Furthermore stability studies of TELM were carried out under acidic, alkali, neutral, oxidation, photolytic, and thermal degradation as per stability indicating assay methods.

Results:

The results of analysis have been validated, and recovery studies were carried out using a standard addition method by adding specific drug amount (80%, 100%, and 120%) and show recovery studies in the range (99.26–101.26)%.

Conclusion:

The proposed method can be successfully applied for method development, validation, and stability study of TELM.