Journal of Planar Chromatography VOL. 18. JANUARY/FEBRUARY 2005 19 Summary A simple and rapid densitometric method has been developed for determination of desloratadine in tablets. After extraction of the samples with 96% ethanol the solutions were spotted on precoated silica gel TLC plates and these were eluted with ethyl acetate– n-butanol–25% aqueous ammonia–methanol, 21 + 5.0 + 4.0 + 5.0 (v/v), as mobile phase. Quantitative evaluation was performed by measuring the absorbance reflectance of the desloratadine spots at λ = 279 nm. The TLC–densitometric method is selective, precise, and accurate and can be used for routine analysis of tablets in phar- maceutical industry quality control laboratories. 1 Introduction Desloratadine (descarboethoxyloratadine; chemical name 8- chloro-6,11-dihydro-11-(4-piperidinylidene)-5H-benzo[5,6]cyc- lohepta[1,2-b]pyridine) is a long-acting tricyclic histamine antagonist with selective H 1 -receptor histamine antagonist activity. The drug is used to treat allergenic rhinitis and chronic idiopathic urticaria [1]. Desloratadine is the major metabolite of loratadine, and less bound to plasma protein than loratadine [2]. This drug is available commercially in Indonesia. No official method for assay of desloratadine is available in some Pharmacopoeias [3–5]. Liu and Wang [6] reported a high- performance liquid chromatographic (HPLC) method for bioe- quivalence evaluation of desloratadine fumarate tablets in dogs. Zhang et al. [7] and Yang et al. [8] described liquid chromato- graphic–tandem mass spectrometric methods for determination of desloratadine in human plasma. No TLC methods have been reported for determination of desloratadine in pharmaceutical preparations [9], although the TLC–densitometric determina- tion of loratadine in pharmaceuticals has been described by Indrayanto et al. [10]. The objective of this work was to develop a cheap, rapid, and simple validated TLC method for determination of deslorata- dine in pharmaceutical preparations, for use in pharmaceutical industry quality-control laboratories. 2 Experimental 2.1 Materials and Reagents Desloratadine (Sun Pharmaceutical, Gujarat, India; lot 8024/110/23; assay 99.4%; manufacture date May 2002; expiry date April 2005) was pharmaceutical-grade substance. It was used as received for preparing laboratory-made tablets, and standard solutions. Commercial tablets containing deslorata- dine (5 mg tablet –1 ; batch T2STBA049; expiry date September 2004) were purchased in a local pharmacy in Surabaya in March 2004. The commercial tablets were produced in Indonesia. Ethyl acetate, n-butanol, 25% aqueous ammonia, methanol, and 96% ethanol (Mallinckrodt Baker, Phillipsburg, NJ, USA) were analytical-grade reagents and were used without further purifi- cation. Excipients for laboratory-made tablet preparations (magnesium stearate, lactose, calcium diphosphate, talc, poly- ethylene glycol, polyvinyl pyrolidone, titanium oxide, corn starch, Eudragid E-100, Vivastar, and Emco Blue) were phar- maceutical-grade substances. Laboratory-made tablets were prepared containing five different concentrations of deslorata- Densitometric Determination of Desloratadine in Tablets, and Validation of the Method Endang Sumarlik, Hoshi Berniati Tampubolon, Mochammad Yuwono, and Gunawan Indrayanto* Key Words: TLC Densitometry Tablet Validation Desloratadine E. Sumarlik and H.B. Tampubolon, QC Laboratory, Bernofarm Pharmaceutical Company, Buduran, Sidoarjo, Surabaya 61252, Indonesia; and M. Yuwono and G. Indrayanto, Assessment Service Unit, Faculty of Pharmacy, Airlangga University, Jl. Dharmawangsa dalam, Surabaya 60286, Indonesia. DOI: 10.1556/JPC.18.2005.1.3