Browsing by Author "Akay, Cemal"
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
Item Determination of theophylline and ephedrine HCL in tablets by ratio-spectra derivative spectrophotometry and LC(Pergamon-Elsevier Science, 2002-06-20) Şentürk, Zühre; Erk, Nevin; Özkan, Sibel A.; Akay, Cemal; Cevheroğlu, ŞemsettinTwo methods are described for the determination of theophylline (THP) and ephedrine hydrochloride (EPH) in combined pharmaceutical tablet forms. The first method depends on the use of the first derivative of the ratio-spectra obtained by dividing the absorption spectrum of binary mixtures by a standard spectrum of one of the compounds. The first derivative amplitudes at 231.8 and 250.3 nm were selected for the assay of THP and EPH, respectively. Calibration graphs were established for 20-180 mug ml(-1) for THP and 10-50 mug ml(-1) for EPH. The second method is based on high-performance liquid chromatography on a reversed-phase column using a mobile phase of methanol-water (40 + 60,v/v) (pH 3) with detection at 217 nm. Linearity was obtained in the concentration range of 5-150 mug ml(-1) for THP and 15-75 mug ml(-1) for EPH. The detection limits for THP and EPH were 0.73 and 0.92 mug ml(-1) by ratio-spectra derivative spectrophotometry and 0.59 and 0.86 mug ml(-1) by HPLC, respectively. The proposed methods were successfully applied to the determination of these drugs in laboratory-prepared mixtures and in tablets. The relative standard deviations were found to be less than 1.5%, indicating reasonable repeatibility of both methods.Item The effects of azone and capsaicin on the permeation of naproxen through human skin(Elsevier Science BV, 1999-03-01) Degim, İ. Tuncer; Uslu, A.; Hadgraft, Jonathan; Atay, T.; Cevheroğlu, S.; Akay, Cemal; Uludağ Üniversitesi/Tıp Fakültesi.; 0000-0002-2306-5451; AAA-7011-2021The permeation of naproxen through excised human skin and isolated perfused rabbit ear skin has been determined. It was found that both Atone and capsaicin enhanced the permeation with an enhancement ratio of up to 4-fold. The magnitudes of the effect were similar in human and rabbit skin. The permeation of naproxen from a saturated solution of the drug through skin pre-treated with Atone was similar to that from a commercial preparation (Naprosyn). In the perfused rabbit ear experiments the presence of capsaicin had no effect on the vasodilatation of the blood vessels, inferring that the penetration enhancement was a direct result of capsaicin influencing the barrier function of the skin. Structural similarities between Atone and capsaicin were seen using molecular graphics.Item Screening for hemochromatosis in Turkey(Springer, 2004-03) Bozkaya, Hakan; Bektaş, Mehmet; Metin, Olga; Erkan, Özlem E.; İbrahimoğlu, Dicle; Dalva, Klara; Akbıyık, Filiz; Bozdayı, Abdurrahman Mithat; Akay, Cemal; Yurdaydın, Cihan; Aslan, Önder; Uzunalimoğlu, Özden; Gürel, Selim; Uludağ Üniversitesi/Tıp Fakültesi/Gastroenteroloji Bilim Dalı.; 7003706434In this study we screened 3060 consecutive blood donors for an unbound iron-binding capacity level of <28 mu M and then performed HFE mutation analysis in these subjects. Sixty-five of the 75 subjects with a low initial unbound iron-binding capacity (all had normal ferritin levels) came back and only 5 (8%) had a low fasting unbound iron-binding capacity. Mutational analysis revealed H63D heterozygosity in two of five subjects. Four of five subjects had liver biopsy indication and none had increased liver iron. HFE genotyping of 60 subjects with a low initial but normal fasting unbound iron-binding capacity revealed heterozygote H63D in seven (11.6%). No allelic variant of position 282 or 63 was found in three previously diagnosed patients with hereditary hemochromatosis. In conclusion, full phenotypic expression of hereditary hemochromatosis is very rare in Turkey. The absence of HFE mutations in three patients with hereditary hemochromatosis suggests that hereditary hemochromatosis in Turkey occurs without common HFE mutations.Item Simultaneous determination of metronidazole and miconazole in pharmaceutical dosage forms by RP-HPLC(Elsevier Science, 2002-11) Akay, Cemal; Özkan, Sibel A.; Şentürk, Zühre; Cevheroğlu, Şemsettin; Uludağ Üniversitesi/Tıp Fakültesi.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 Cl 8 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 mug ml(-1) with detection limits 0.33 and 0.27 mug 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. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.