APPLICATIONS OF A NEW METHOD OF DETERMINING LORATADINE BY HPLC/DAD FROM VARIOUS DOSAGE FORMS AND BIOLOGICAL SAMPLES

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-20-9 / ISSN 1314-2704, June 19-25, 2014, Book 6, Vol. 1, 269-276 pp

ABSTRACT
The aim of current study is to see if this new HPLC/DAD method, which was
performed, established and validated in our previous researches, is suitable for the analysis of drugs in pharmaceutical chemistry and for clinical purpose.
HPLC/DAD method was applied to various pharmaceutical forms, from the Romanian market (oral tablets with loratadine, modified release tablets with loratadine and pseudoephedrine sulphate and syrup with loratadine) and biological samples (serum, urine and breast milk). For the determination of loratadine in human serum and urine were sampled blood and urine of 6 healthy volunteers, who agreed to receive loratadine orally in doses of 10 mg once daily (normal therapeutical dosage) at the same time (9:00 AM). The sample of breast milk has been taken from a woman volunteer diagnosed with urticaria, two months after giving birth. The sampling was done to 0 hour, 1 hours, 2 hours, 3 hours, 6 hours and 8 hours after the administration of antihistamine treatment (10 mg loratadine). All volunteers are adults, similar ages, race and weight. Sampling was done during three days at the same time of day. Chromatographic conditions were as follows: HPLC Agilent 1200 quaternary pump, DAD, thermostat, degassing system, autosampler, column chromatography type C18 (250 x 4.6) 5μm XDB - C18 Agilent (Zorbax Eclipse XDB-18 or equivalent, flow 1 mL/min, column temperature: 27°C, injection volume: 10 mL, mobile phase: 0.01% solution of triethylamine adjusted to pH = 2.75 with ortho-phosphoric acid / acetonitrile (46/54, v/v)] - isopropanol (90/10, v/v), detection: 264 nm; the concentration of samples was calculated using the calibration equation and then it was statistically processed. A recovery of 98.51% was registered on tablets with loratadine compared to the declared content of active substance. The recovery of 92.71% on modified release tablets with loratadine and pseudoephedrine sulphate and a 102.49% recovery on loratadine syrup were recorded. All values are within the permissible deviations according to European Pharmacopoeia. A small increase of unmethabolised loratadine concentration in first time interval and then a decrease due to metabolism and renal elimination was noticed in serum samples. This method reveals the presence of loratadine in urine and breast milk without being altered by other components of the samples. HPLC method is sensitive and can detect traces of loratadine in all biological samples whereas its peak does not interfere with other peaks of sample components. Finally, this method proved to be sensitive, valid and reliable in determination of loratadine in various dosage forms and biologic samples.

Keywords: loratadine, HPLC/DAD method, dosage forms, biologic samples,
selectivity, sensitivity.