HPTLC-densitometric determination of cetirizine and montelukast analysis in combined tablet dosage forms

A simple, accurate and rapid high performance thin layer chromatography [HPTLC]-densitometric method was developed for separation and determination of cetirizine [CET] as a long acting antihistamine and montelukast [MON] as an antileukotriene in pharmaceutical dosage forms. The compounds were separated on silica gel 60 F[254] HPTLC plates using a mixture of ethyl acetate: methanol: ammonia solution [25%] [14: 3: 2 v/v/v] as mobile phase. The plates were developed vertically up to a distance of 80 mm. Compact spots of both cetirizine [R[f] = 0.30 +/- 0.01] and montelukast [R[f] = 0.52 +/- 0.02] were obtained. UV detection was performed at 230 nm. Quantitative analysis was performed by absorbance densitometry using peak area. The method was validated in terms of linearity, precision, accuracy, limit of detection [LOD], and limit of quantification [LOQ]. The calibration curves were linear in the range of 40-2000 ng spot[-1] for cetirizine and 120-1000 ng spot[-1] for montelukast. For MON, recovery varied in range of 99.20-100.88% with RSD ranging from 1.02 to 1.90% and for CET, recovery varied in range of 98.13-100.05% with RSD ranging from 1.57 to 1.85%. The LODs were found to be 3.94 and 2.08 ng spot[-1] for CET and MON, respectively. It was observed that the proposed HPTLC method could be used for efficient analysis and monitoring of the CET and MON in combined tablet dosage forms, more convenient with better precision and accuracy than HPLC method

Antioxidant activity of mojabanchromanol, a novel chromene, isolated from brown alga Sargassum siliquastrum.

Silica gel chromatography HPLC, El-Mass, and NMR analyses were performed in order to determine the structure obtained from the separation and refinement of the main components of an ethanol extraction of Sargassum siliquastrum, which indicated its antioxidant activity An ethanol extraction of Sargassum siliquastrum demonstrated the strongest antioxidant activities of ethyl acetate when isolated by silica gel chromatography This amounts to 84.9 +/- 1.2% of its 0.5 mg ml(-1) concentration. The thiobarbituric acid reactive substances (TBARS) measurements from 3 isolations of an HPLC separation of ethyl acetate showed that the antioxidant activity of peak 2 was the most dominant at 84.08% in a 0.5 mg ml(-1) concentration. Peak 2 was verified as a type of chromene through El-Mass and NMR analysis. Its metal sealing characteristic was low while its characteristic of TBARS and DPPH erasure indicated similar or higher levels of metal sealing characteristic. The NMR spectroscopic data was used to elucidate the structure of this new compound, which showed strong antioxidant activity in the assay.

Bitter principles of chelonanthus chelonoides

From the whole plants of Chelonanthus cheloniodes two new bitter secoiridoid glucosides, chelonanthoside A and B (1 and 3) have been isolated as the acetates together with sweroside(5). Their structures were elucidated on the basis of chemical and extensive spectral analyses.