A Review on Various Analytical Methods on Some Alpha Adrenergic Antagonists

Alankar      Shrivastava; Vipin      B. Gupta

Abstract

Background: Although initially introduced for the management of hypertension, αl-adrenergic-receptor antagonists (αlblockers) have become the standard of care for the medical management of benign prostatic hyperplasia (BPH) related lower urinary tract symptoms (LUTS). Alpha-blockers (alfuzosin, tamsulosin, doxazosin, prazosin and terazosin) relax the smooth muscles in the prostate and are indicated for the symptomatic treatment of BPH due to evidence of their positive and rapid effect on LUTS. However, these agents have the potential to produce orthostatic hypotension and other blood pressure-related adverse effects in normotensive patients and in those receiving concurrent treatment with other antihypertensive agents. As a result, more “uroselective,” less vasoactive αl-blockers have been developed such as tamsulosin and alfuzosin.

Objective: The presented review provides information about the various analytical methods available in the literature to the scientists and health professionals engaged in research relating these drugs such as clinical trials or developing new formulations. Various analytical methods for the estimation of these drugs in bulk or in various matrices like blood, serum, plasma, alone or in combination with other drugs is discussed.

Methods: Relevant articles were identified through a search of the English-language literature indexed in MEDLINE, PubMed, Sciencedirect and the proceedings of scientific meetings from 1977 to 2010. The search terms were benign estimation of alpha one blockers, determination of prazosin, terazosin, tamsulosin, doxazosin, alfuzosin. Similarly HPLC and Spectroscopy methods for estimation of prazosin, terazosin, tamsulosin, doxazosin, alfuzosin.

Results: Total 57 analytical methods were found. 11 spectrophotometry, 39 chromatographic methods including 2 ESI MS/MS, 1 ESI MS, 2 HPTLC, 3 TLC, 17 HPLC with UV, 9 with fluorescence, 1 with electrochemical detection, 4 with MS detector. Other than this 3 voltametry, 1 method each for radioreceptor assay, polarography, capillary electrophoresis and potentiometry titrations were found.

Conclusion: Radioreceptor assay, LC-MS, UPLC-MS methods were found to be the most sensitive for prazosin, terazosin and doxazosin respectively. Likewise, HPLC-MS-MS methods was found as most sensitive method for estimation of tamsulosin and alfuzosin.

Keywords: BPH, Alpha blockers, Alfuzosin, Tamsulosin, Doxazosin, Prazosin, Terazosin, Analytical methods, Spectrophotometry, Radioreceptor Assay, Polarography, Capiller Electrophoresis