The advantages of this procedure are simple chromatographic conditions and sparing the solvent. Open in a separate window Fig. method reduced the duration of the analysis. strong class=”kwd-title” Keywords: Prazosin, Terazosin, Doxazosin, 1 Adrenoreceptor blockers, Stress degradation, Chromatography, Method validation Introduction High Pressure Liquid Chromatography (HPLC) is usually a well-known and widely used analytical technique which is usually prevalent throughout the pharmaceutical industry as BIO-5192 a research tool for the estimation of impurities in drug substances and drug products . As a result of significant technological improvements in instrumentation and column packings, high performance liquid chromatography (HPLC) has emerged as the preferred method for the separation and quantitative analysis of a wide range of samples . Stability screening forms an important part of the process of drug product development. The purpose of stability testing is to provide evidence on how the quality of a drug substance varies with time under the influence of a variety of environmental factors such as heat, humidity, and light, which enables recommendation of storage conditions, retest periods, and establishing shelf life . An ideal stability-indicating chromatographic method should estimate the drug and also be able to handle the drug from its degradation products . The stability-indicating assay is usually a method that is employed for the analysis of stability samples in the pharmaceutical industry. It is also required that analytical methods should be validated to demonstrate that impurities unique to the new drug substance do not interfere with or are separated from specified and unspecified degradation products in the drug BIO-5192 product . The condition known as benign prostatic hyperplasia may be defined as a benign enlargement of the prostate gland resulting from a proliferation of both benign epithelial and stromal elements. It might also be defined clinically as a constellation of lower urinary tract symptoms (LUTSs) in aging men . Traditionally, the pathogenesis of benign prostatic hyperplasia (BPH) and LUTS was explained as the conversation between hormonal and genetic factors . The medical treatment of LUTS/BPH mainly entails the inhibition of the enzyme 5-reductase to reduce prostate size and 1-adrenoceptor antagonists. The latter are more frequently used as they reduce LUTS more effectively than the 5-reductase inhibitors in most patients . Alpha-1 blockers are the first option for the medical treatment of LUTS caused by BPH . Their effects are prompt, are well-tolerated, and remain efficacious in the long-term . -Adrenoreceptor antagonists are frequently used to treat patients with LUTS and benign prostatic enlargement because of their significant effect on BIO-5192 storage (of urine) and voiding symptoms, quality of life, flow rate, and postvoid residual urine volume . Tal1 Potentiometric titration is an official method in British Pharmacopoeia  and Indian Pharmacopoeia  with 0.1 M perchloric acid as a titrant for the determination of prazosin. Radioreceptor assay  and voltametric  estimation methods are also found. The titrimetry method for the determination of terazosin by using 0.1 N NaOH, is official in European pharmacopoeia . Other literature about the potentiometric estimation of terazosin  using 0.1 N perchloric acid and 0.1 N silver nitrate solution as the titrant, and by using a modified glass calomel electrode and glass silver electrode pair system, respectively, is also available. For doxazosin, two voltametric [17, 18] and polarographic  methods are reported in the current literature. Six spectrophotometry [14, 17, 20C23], four TLC [16, 25], twenty-six HPLC [13, 15, 16, 25C35], one HPTLC , and one HILIC-MS/MS  were methods in various matrixes that were also found during the literature survey. However, the common mobile phase in which drugs under investigation may separate, is reported by Bakshi et al . In this method terazosin, prazosin, and doxazosin were run separately under same chromatographic conditions. The retention time of the terazosin and prazosin is close enough for them to merge if simultaneous determination is attempted for the determination of these structurally similar drugs. Prazosin, terazosin, and doxazosin contain same parent quinazoline (Figure 1) nucleus, and thus it is especially difficult to separate the former two drugs. Applications of conventional UV spectrophotometric methods are limited due to the spectral overlap throughout the wavelength. So, the gradient HPLC method can be used to overcome this problem. The proposed method reduced the duration of the analysis. This theory forms the basis of our study. Thus a simple and sensitive method for the routine determination of these pharmaceuticals in formulations was attempted. The proposed method allows the simultaneous determination of the three 1-adrenoreceptor blockers in this study without the need to carry out previous separation. The advantages of.