title: Operator care and eco-concerned development of a fast, facile and economical assay for basic nitrogenous drugs based on simplified ion-pair mini-scale extraction using safer solvent combined with drop-based spectrophotometry.
abstract: A fast, facile, and economical assay for basic nitrogenous drugs has been developed based on the mini-scale extraction of the drug-dye ion pair complex combined with the use of safe-for-analyst and eco-friendlier organic extractant and drop-based micro-spectrophotometry. Instead of using large volume devices, the extraction was simply carried out in typical 1.5 mL microcentrifuge tubes along with the use of micropipettes for accurate transfer of liquids, vortex mixer for efficient partitioning of solutes and benchtop centrifuge for rapid phase separation. In the last step, back-extraction was performed by using the microvolume of acidic solution in order to concentrate the colored species into a confined aqueous microdrop and to keep the analyst away from unwanted contact and inhalation of organic solvents during the quantitation step which was achieved by using cuvetteless UV-vis micro-spectrophotometry without any prior dilutions. Using chlorpheniramine maleate as a representative analyte and n-butyl acetate as a less toxic and non-ozone depleting extractant, the miniaturized method was less laborious and much faster. It was accurate, precise and insensitive to the interferences from common excipients. Notably, it gave the assay results of drug in tablets and oral solution comparable to the large-scale pharmacopeial method while the consumption of organic solvents and the release of wastes were lowered by 200-400 folds.
authors.affiliation: Pharmaceutical Development of Green Innovations Group (PDGIG), Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand.
authors.forename: Samarwadee
authors.initials: S
authors.lastname: Plianwong
authors.forename: Areerut
authors.initials: A
authors.lastname: Sripattanaporn
authors.forename: Kwanrutai
authors.initials: K
authors.lastname: Waewsa-nga
authors.forename: Parin
authors.initials: P
authors.lastname: Buacheen
authors.forename: Praneet
authors.initials: P
authors.lastname: Opanasopit
authors.forename: Tanasait
authors.initials: T
authors.lastname: Ngawhirunpat
authors.forename: Theerasak
authors.initials: T
authors.lastname: Rojanarata
mesh_terms: D000085:Acetates / Q000737:chemistry; D002744:Chlorpheniramine / Q000032:analysis*; D055772:Green Chemistry Technology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D009574:Nitro Compounds / Q000032:analysis*; D055553:Prescription Drugs / Q000032:analysis*; D012996:Solutions; D013053:Spectrophotometry; D013607:Tablets
chemical_list: D000085:Acetates; D009574:Nitro Compounds; D055553:Prescription Drugs; D012996:Solutions; D013607:Tablets; D002744:Chlorpheniramine; C006848:butyl acetate