Sulfathiazole analysis

In its heyday, DTA analysis was very useful for the study of compound polymorphism and in the characterization of solvate species of drug compounds. It was used to deduce the ability of polymorphs to undergo thermal interconversion, providing information that could be used to deduce whether the system in question was monotropic or enantiotropic in nature. For instance, the enthalpies of fusion and transition were measured for different polymorphs of sulfathiazole and methylprednisolone [24]. The DTA thermograms shown in Fig. 4.5 demonstrate that Form-I is metastable with respect to Form-II, even... 

M. Lopez-Sanchez, M.J. Ruedas-Rama, A. Ruiz-Medina, A. Molina-Diaz and M.J. Ayora-Canada, Pharmaceutical powders analysis using FT-Raman spectrometry Simultaneous determination of sulfathiazole and sulfanilamide, Talanta, 74, 1603-1607 (2008). 

Sulfacetamide, A benzoyl sulfanilamide and sulfathiazole have been determined in pharmaceutical preparations by measuring absorbance of the mixture in 0.1 N hydrochloric acid at 220,235 and 280 nm respectively (42). Madsen et al. (43,44) have performed computer analysis of the multicomponent UV spectra of sulfonamides. The errors in concentration determined from the spectra between 240 and 272 nm are lower when the spectra are analysed by a linear-squares method considering the data over the whole wavelength range compared with the determination using the data at a single wave length. The method has been applied to the assay of sulfacetamide sodium eye-drops. 

The goal of early stage solid-state analysis is the determination of the tendency of a compound to crystallize into different forms. It may have many forms like sulfathiazole with at least four polymorphs [6] or methylestradiol with one anhydrous form, two hydrated forms and at least two solvated forms [4]. This information guides the course of the future studies. If only one pharmaceutically significant form exists, then the subsequent studies should be straightforward and relatively rapid. If many forms exist, choosing the optimal form for development may require extensive time and study. It is useful to operate on the principle that all organic compounds crystallize in different forms and that the only questions are How many and How important McCrone [7] put the matter this way ... 

Thermal analysis has been used to identify and characterize polymorphs of chlordiazepoxide hydrochloride, phenobarbital monohydrate, chloramphenicol palmitate, 3 (3-hydroxy-3-methyl-butylamino)-5-methyl-as. triazino ZB,6-b7 indole (SKF 30097), sulfathiazole, and sulfanilamide-d4. Solubility vs. solvent composition diagroms have been useful in the systematic study of pseudopolymorphism in the antibiotics cephaloglycin and cephalexin. This technique is recommended for the detection of solvate farmation when the instability of the compound at elevated temperatures precludes the use of conventional thermal methods, or when poor crystal development limits the use of microscopic methods. 

McGrane, M. O Keeffe, M. Smyth, M.R. The analysis of sulphonamide drug residues in pork muscle using automated dialysis, Anal.Lett., 1999, 32, 481-495. [LOD 40 ng/g sulfadiazine sulfathiazole sulfapyridine sulfamerazine suRamethizole sulfamethazine sulfamethoxypyridazine sulfachlorpyridazine sulfisoxazole]... 

Mahedero MC, Mora Diaz N, Munoz de la Pena A, Espinosa Mansilla A, Gonzalez Gomez D, Bohoyo Gil D. Strategies for solving matrix effects in the analysis of sulfathiazole in honey samples using three-way photochemicaUy induced fluorescence data. Talanta 2005 65 806-13. 

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