%0 Journal Article
%T New Spectrophotometric and Conductometric Methods for Macrolide Antibiotics Determination in Pure and Pharmaceutical Dosage Forms Using Rose Bengal
%A Rania A. Sayed
%A Wafaa S. Hassan
%A Magda Y. El-Mammli
%A Abadalla Shalaby
%J Journal of Spectroscopy
%D 2013
%R 10.1155/2013/214270
%X Two Simple, accurate, precise, and rapid spectrophotometric and conductometric methods were developed for the estimation of erythromycin thiocyanate (I), clarithromycin (II), and azithromycin dihydrate (III) in both pure and pharmaceutical dosage forms. The spectrophotometric procedure depends on the reaction of rose bengal and copper with the cited drugs to form stable ternary complexes which are extractable with methylene chloride, and the absorbances were measured at 558, 557, and 560 nm for (I), (II), and (III), respectively. The conductometric method depends on the formation of an ion-pair complex between the studied drug and rose bengal. For the spectrophotometric method, Beer's law was obeyed. The correlation coefficient ( ) for the studied drugs was found to be 0.9999. The molar absorptivity ( ), Sandell¡¯s sensitivity, limit of detection (LOD), and limit of quantification (LOQ) were also calculated. The proposed methods were successfully applied for the determination of certain pharmaceutical dosage forms containing the studied drugs 1. Introduction The macrolides are a large group of antibiotics mainly derived from Streptomyces. They have a common macrocyclic lactone ring to which one or more sugars are attached and are all weak bases that are only slightly soluble in water [1]. They are bacteriostatic agents. They inhibit protein synthesis by binding reversibly to 50 S ribosomal subunit of sensitive microorganisms [2]. Macrolides and related drugs have a postantibiotic effect, that is, antibacterial activity persists after concentrations have dropped below the minimum inhibitory concentration [1]. Erythromycin is produced by the actinomycete species, Streptomyces erythreus. Erythromycin is a polyhydroxylactone that contains two sugars. The aglycone portion of the molecule, erythranolide, is a 14-membered lactone ring. An amino sugar, desosamine, is attached through a ¦Â-glycosidic linkage to the C-5 position of the lactone ring. The tertiary amine of desosamine confers a basic character to erythromycin (pKa 8.8). Through this group, a number of acid salts of the antibiotic have been prepared. A second sugar, cladinose, which is unique to erythromycin, is attached via a ¦Â-glycosidic linkage to the C-3 position of the lactone ring [3]. It is commonly used to treat infections caused by gram-positive organisms, Mycoplasma species, and certain susceptible gram-negative and anaerobic bacteria within respiratory tract, skin, soft tissues, and genital tract [4]. More recently developed macrolides, including azithromycin and clarithromycin, seem to have
%U http://www.hindawi.com/journals/jspec/2013/214270/