Development and Validation of First-Order Derivative Spectrophotometry for Simultaneous Determination of Levocetirizine Dihydrochloride and Phenylephrine Hydrochloride in Pharmaceutical Dosage Form

A simple, precise, accurate, and economical spectrophotometric method has been developed for simultaneous estimation of levocetirizine dihydrochloride (LCT) and phenylephrine hydrochloride (PHE) by employing first-order derivative spectrophotometric method. The first-order derivative absorption at 240？nm (zero crossing point of PHE) was used for quantification of LCT and 283.2？nm (zero crossing point of LCT) for quantification of PHE. The linearity was established over the concentration range of 4–24？μg/mL and 8–48？μg/mL for LCT and PHE with correlation coefficients ( ) 0.9964 and 0.9972, respectively. The mean % recoveries were found to be in the range of 99.14%–100.43% for LCT and 98.73%–100.83% for PHE. The proposed method has been validated as per ICH guideline and successfully applied for the simultaneous estimation of LCT and PHE in combined tablet dosage form. 1. Introduction The chemical name of levocetirizine dihydrochloride (LCT) is [2-[4-[(R)-(4-Chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy]-acetic acid dihydrochloride [1]. The structure of LCT is given in Figure 1. LCT is a third generation nonsedative antihistamine, developed from the second generation antihistamine cetirizine. Chemically, LCT is the active L-enantiomer of cetirizine racemate. It works by blocking H1 histamine receptors. It is used in the treatment of the allergic rhinitis and conjunctivitis, hay fever, pollinosis—control sneezing, runny but not blocked nose, and red, watering, and itchy eyes [2]. Figure 1: Chemical structure of LCT. The chemical name of phenylephrine hydrochloride (PHE) is (R)-3-Hydroxy-alpha [(methylamino)methyl]benzenemethanol hydrochloride [3]. The structure of PHE is given in Figure 2. PHE is a direct acting sympathomimetic agent. It is a selective adrenoceptor agonist and has negligible action. It is also a vasoconstrictor, because it has little cardiac action. It is mainly used as a nasal decongestant and for producing mydriasis when cycloplegia is not required. It tends to reduce intraocular tension by constricting ciliary body blood vessels [2]. Figure 2: Chemical structure of PHE. LCT and PHE in combined dosage form are used as a nasal decongestant. The review of the literature revealed that various analytical methods involving spectrophotometry, HPLC, HPTLC, and LC-MS have been reported for LCT alone and in combination with other drugs [4–14]. Several analytical methods have been reported for PHE alone and in combination with other drugs including spectrophotometry, HPLC, HPTLC, LC-MS/MS, and electrophoresis [15–23]. However, to the best of our