Quantitative Analysis of Irbesartan in Commercial Dosage Forms by Kinetic Spectrophotometry

Response surface methodology combined Box-Behnken design optimized green kinetic spectrophotometric and HPLC methods to quantify angiotensin receptor blocker valsartan in pharmaceutical formulations

The high-performance liquid chromatographic (HPLC) and kinetic spectrophotometric methods were established to compute valsartan (VAL) in pharmaceutical formulations. The spectrophotometric procedures adopted initial rate, fixed time, and equilibrium strategies to assess VAL. The method was based on the carboxylic acid group of the oxidized VAL with a mixture of potassium iodate (KIO₃) and potassium iodide (KI) at room temperature, producing a stable, yellow-coloured absorb at 352 nm. The critical parameters were optimized using green process optimization methodology such as Box-Behnken design (BBD) which belongs to response surface methodology (RSM). After the screening, experiments identified them as significant, and then three crucial factors were optimised: KI volume, KIO₃ volume, and reaction time against response as absorbance. The HPLC procedure was also optimized based on the desirability function on RSM-BBD. The parameters such as pH, methanol (%), and flow rate (ml/min) were optimized with the best responses: peak area, symmetry, and theoretical plates. The linearity of spectrophotometric and HPLC methods was within the range of 2-24 and 0.25-11.25 µg/ml, respectively. The developed procedures produced excellent accuracy and precision. The design of the experiment (DoE) setting explained and discussed the individual steps and the importance of independent and dependent variables used to develop the model and optimization. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Furthermore, Youden's robustness study was applied with factorial combinations of the preferred analytical parameters and explored their influence with alternative conditions. The analytical Eco-Scale score was calculated and was found a better option as green methods to quantify VAL. The results were reproducible with the analysis completed with biological fluid and wastewater samples.

Irbesartan (a comprehensive profile)

Irbesartan, (2-butyl-3-({4-[2-(2H-1,2,3,4-tetrazol-5-yl)phenyl]phenyl}methyl)-1,3-diazaspiro[4.4]non-1-en-4-one), is a member of non-peptide angiotensin II receptor antagonists used worldwide in the treatment of hypertension and diabetic nephropathy in hypertensive patients with type 2 diabetes, elevated serum creatinine, and proteinuria. Irbesartan can be used alone or in combination with other antihypertensive agents (e.g., hydrochlorothiazide). These combination products are indicated for hypertension in patients with uncontrolled hypertension with monotherapy or first line in patients not expected to be well controlled with monotherapy. Irbesartan is also indicated for the treatment of diabetic nephropathy in patients with type 2 diabetes and hypertension, an elevated serum creatinine, and proteinuria. Irbesartan exerts its action mainly via a selective blockade action on AT1 receptors and the consequent reduced pressor effect of angiotensin II. This article discusses, by a critical comprehensive review of the literature on irbesartan in terms of its description, names, formulae, elemental composition, appearance, and therapeutic uses. The article also discusses the methods for preparation of irbesartan, its physical-chemical properties, analytical methods for its determination, pharmacological-toxicological properties, and dosing information.

Selective and validated kinetic spectrophotometric method for the determination of irbesartan in pure and pharmaceutical formulations

A novel-coupling reagent is used for the simple and sensitive kinetic spectrophotometric determination of irbesartan (IRB) in pure or pharmaceutical formulations. The method utilizes an oxidative coupling reaction based on oxidation of 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) with Ce(IV) in 2% sulfuric acid medium, followed by coupling the produced electrophilic intermediate (diazonium salt of the reagent) with IRB to give greenish-blue colored product (1:1, stoichiometry) having maximum absorption at 629nm and the colored species is stable for more than 1h. The initial rate and fixed time (at 35min) methods are adopted for determination of IRB concentration. The linearity is in the ranges of 5.0-40.0μg/mL and 2.0-45.0μg/mL and the limit of detection is 0.46 and 0.40μg/mL for initial rate and fixed time methods, respectively. Molar absorptivity for the method was found to be 1.50×10⁴L/molcm. The validated kinetic methods can be successfully applied to the analysis of IRB in bulk and tablet dosage form and in the routine quality control analysis. The percentage recoveries were above 100% for both methods. The excipients did not interfere in the analysis.

Simultaneous determination of some anti-hypertensive drugs in their binary mixture by novel spectrophotometric methods

Three simple, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of Irbesartan (IRB) and Hydrochlorothiazide (HCT) without prior separation namely; ratio subtraction coupled with constant multiplication (RS-CM), ratio difference (RD) and constant center (CC). The accuracy, precision and linearity ranges of the proposed methods were determined, and the methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the cited drugs. The three methods were applied for the determination of the cited drugs in tablets and the obtained results were statistically compared with each other and with those of official methods. The comparison showed that there is no significant difference between the proposed methods and the official methods regarding both accuracy and precision.