ACTA FAC MED NAISS 2013;30(2):63-71

Original article

UDC:615.281:615.454.1:618.15-002

DOI:10.2478/v10283-012-0038-y

Determination of Clindamycin Phosphate in Different Vaginal Gel Formulations

by Reverse Phase High Performance Liquid Chromatography

Milica Stanković¹, Vesna Savić¹, Valentina Marinković²

¹University of Niš, Faculty of Medicine, Department of Pharmacy, Serbia

²University of Belgrade, Faculty of Pharmacy, Serbia


summary

Clindamycin is an antibiotic effective against Gram-positive aerobes and both Gram-negative and Gram-positive anaerobic pathogens. Clindamycin (its phosphate ester) was used as a model drug for our study in order to check the efficacy of the developed vaginal gel formulations. The aim of this study was to develop an analytical method suitable for the determination of clindamycin phosphate in three different vaginal gel formulations. The main difference between the three formulations was the use of different gelation agents in the formulations (Carbopol® 940, Carbopol® Ultrez 10 and Pemulen® TR 1). A new isocratic high performance liquid chromatography method based on reverse phase separation has been developed for the determination of clindamycin phosphate. The separation was achieved on a Zorbax Eclipse plus C8 column with a mobile phase of acetonitrile and pH 2.5 phosphate buffer and UV detection at 210 nm. A linear response (r>0.99) was observed in the range of 10.0-80.0 µg mL-1. The method shows good recoveries and relative standard deviations were less than 1.0%. The method can be applied to assess the stability of clindamycin phosphate in vaginal gel formulations. It can be used for quality control and stability study samples analysis. Clindamycin phosphate concentration was different in vaginal gel formulations with different gelation agents, so the conclusion is that gelation agents (gel carriers) have a significant influence on the active drug concentration. The obtained results confirm that vaginal gel formulation with Carbopol® 940 shows the maximal stability during the analysis and provides the optimal value of clindamycin phosphate concentration.

Key words: clindamycin phosphate, reversed phase chromatography, vaginal gels, Carbopol® 940