Use of Two Sulfonphthalein Dyes for the Sensitive and Selective Extraction-Free Spectrophotometric Assay of Albendazole in Bulk Drug and in Tablets

Abstract

Albendazole (ALB) is a potent benzimidazole anthelmintic used in the treatment of human intestinal helmintiasis as well as of hytatid cysts and neurocysticercosis. Two rapid, simple, sensitive, and selective spectrophotometric methods are presented for the determination of ALB in pharmaceuticals. The methods are based on the formation of dichloromethane soluble 1 : 1 ion-pair complexes (ALB : dye) formed between ALB and sulfonphthalein dyes, bromophenol blue BPB, (method A) and bromothymol blue BTB, (method B). The complexes formed were measured directly (without extraction) at 445 nm (method A) and 460 nm (method B). The experimental conditions were optimized and the systems obey Beer’s law for 1.5–21.0 and 2.0–32.0 μg mL−1 ALB for method A and method B respectively. The molar absorptivity and Sandell's sensitivity were calculated to be L mol−1 cm−1 and 0.0209 ng cm−2, and L mol−1 cm−1 and 0.0350 ng cm−2 using BPB and BTB, respectively. The limits of detection and quantification were calculated to be 0.01 and 0.03, and 0.16, and 0.49 μg mL−1 using BPB and BTB, respectively. The relative standard values for intra-day and inter-day precision were less than 3%, and the accuracy was better than 3% for both methods.

Analytical methods for determination of terbinafine hydrochloride in pharmaceuticals and biological materials

“…The reviewed extractive spectrophotometric methods based on ion-association reactions were plagued by several disadvantages. In recent years, there has been a surge in the use of spectrophotometry without liquid-liquid extraction step as a sensitive tool in pharmaceutical analysis [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] . This new approach can be used in place of extractive spectrophotometry for terbinafine.…”

A New Non-Extractive Ion-Pair Spectrophotometric Method for the Assay of Albendazole

“…Extraction is a laborious procedure and the trends are to develop non-extractive (extraction-free) methods. For the determination of ABZ two nonextractive ion pair spectrophotometric methods are reported [23]. The objective of this work was to investigate the ability of ABZ to form ion pairs, in aqueous media, in order to develop a non-extractive spectrophotometric assay method.…”