Short Communication Simultaneous determination of metronidazole and miconazole in pharmaceutical dosage forms by RP-HPLC Cemal Akay a , Sibel A. O ¨ zkan b, *, Zu ¨hre S ¸ entu ¨rk c ,S ¸ emsettin Cevherog ˘lu d a Department of Pharmaceutical Sciences, Gu ¨lhane Military Medical Academy, 06018 Ankara, Turkey b Department of Analytical Chemistry, Faculty of Pharmacy, Ankara University, 06100 Ankara, Turkey c Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey d Turkish Army Drug Factory, 06110 Ankara, Turkey Received 1 February 2002; accepted 6 July 2002 Abstract A reversed-phase high performance liquid chromatography (RP-HPLC) method with UV detection is described for the simultaneous determination of metronidazole and miconazole in pharmaceutical dosage forms. Chromatography was carried out on a C18 reversed-phase column, using a mixture of methanol /water (40 /60, v/v) as a mobile phase, at a flow rate of 1.0 ml min 1 . Sulfamethoxazole was used as an internal standard and detection was performed using a diode array detector at 254 nm. The method produced linear responses in the concentration ranges 10 /70 and 1  /20 mg ml 1 with detection limits 0.33 and 0.27 mg ml 1 for metronidazole and micanozole, respectively. This procedure was found to be convenient and reproducible for analysis of these drugs in ovule dosage forms. # 2002 E ´ ditions scientifiques et me ´dicales Elsevier SAS. All rights reserved. Keywords: Reversed-phase high performance liquid chromatography; Metronidazole and miconazole; Pharmaceutical dosage forms 1. Introduction Metronidazole (MTZ) is a 5-nitroimidazole derivative with activity against anaerobic protozoa and bacteria; it also has a radiosensitising effect on hypoxic tumour cells [1,2]. Miconazole, another imidazole derivative, is applied widely as the nitrate salt (MIC), to treat fungal infections [1,2]. The mixture of MIC with MTZ has been marketed in some commercial preparations for anti- protozoal and antibacterial therapy. Literature survey reveals some methods for the determination of MIC in pharmaceutical preparations or in biological fluids including HPLC [3  /7], gas chromatography [8], spectrophotometry [4,9  /11], spec- troflorimetry [11] and titrimetry [12]. Several methods have also been described for the determination of MTZ either alone or in combination with various drugs, such as spectrophotometry [13  /15], HPLC [16  /22], electro- phoresis [23], and voltammetry [24]. * Corresponding author E-mail address: ozkan@pharmacy.ankara.edu.tr (S.A. O ¨ zkan). Il Farmaco 57 (2002) 953  /957 www.elsevier.com/locate/farmac 0014-827X/02/$ - see front matter # 2002 E ´ ditions scientifiques et me ´dicales Elsevier SAS. All rights reserved. PII:S0014-827X(02)01296-X