Sulfathiazole methods

Sulfonamides prepared from 2-aminoselenazoles by normal methods sometimes possess activity comparable to that of sulfathiazole (45, 47). 

A/ -HeterocycHc derivatives can be formed in some cases by a ring closure to give the heterocycle. Sulfadiazine, sulfamethazine, sulfamerazine, and sulfathiazole have been prepared in this fashion, but also by the usual procedure from the sulfonyl chloride and heterocycHc amine. The synthesis of sulfamethazine from sulfaguanidine is an example of the ring closure method. 

The release kinetics from the tablets of the drug-polymer complexes were carried out in buffered release media containing 0.01 M phosphate and NaCl ranging from 0.2 M to 0.02 M at 37°C by the USP basket method at 100 rpm. Drug release was monitored on a HP 8452A diode-array spectrophotometer at 250, 306, 306, 270, 278, 278, and 274 nm for sodium diclofenac and sulfathiazole, labetalol HCl, propranolol HCl, verapamil HCl, and diltiazem HCl, respectively. 

Raman often is evaluated as an alternative to an existing high performance liquid chromatography (HPLC) method because of its potential to be noninvasive, fast, simple to perform, and solvent-free. Raman was compared to HPLC for the determination of ticlopidine-hydrochloride (TCL) [43], risperidone [44] in film-coated tablets, and medroxyprogesterone acetate (MPA) in 150-mg/mL suspensions (DepoProvera, Pfizer) [45] it was found to have numerous advantages and performance suitable to replace HPLC. In an off-line laboratory study, the relative standard deviation of the measurement of the composition of powder mixtures of two sulfonamides, sulfathiazole and sulfanilamide, was reduced from 10-20% to less than 4% by employing a reusable, easily prepared rotating sample cell [46]. 

Chamot, E. M. and Mason, C. W. (1973). Handbook of chemical microscopy. Vol. 1, 3rd edn. Principles and Use of Microscopes and Accessories. Physical Methods for the Study of Chemical Problems, Wiley-Interscience, New York. [22,46,48, 95] Chan, F. C., Anwar, J., Cernik, R., Barnes, R. and Wilson, R. M. (1999). Ab initio structure determination of sulfathiazole polymorph V from synchroton x-ray powder diffraction data. J. Appl Crystallogr, 32,436 1. [111]... 

In a wide-ranging study, NIR spectroscopy was used to quantitate the phase composition in various forms of sulfamethoxazole, sulfathiazole, lactose, and ampicillin.80 For instance, as shown in Figure 4, the o -mono-hydrate phase of lactose is easily distinguished from /Mactose anhydrate on the basis of the characteristic band at 1940 nm associated with the water combination mode. In all cases, however, properly calibrated NIR methods were able to yield good predictions of phase composition relative to the actual composition of the standards used, and it was concluded that the quantitative NIR was equally effective for such work as other commonly used quantitative methods. 

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. 

HPLC on pBondapak Ph column with UV detection at 280 nm has been used for the determination of sulfacetamide, sulfabenzamide and sulfathiazole in a triple sulfa cream. The mobile phase consists of a 7 3 mixture of 0.01 M ammonium hydrogen phosphate and methanol (pH 7.2). The proposed method has been shown to give better results for sulfacetamide assay compared with those of the USP method (97). Sulfacetamide, sulfadiazine, sulfamerazine and sulfamethazine in mixtures and in pharmaceuticals have been determined by HPLC using a nonpolar column with methanol-0.02 M potassium dihydrogen phosphate in water as the mobile phase and a variable wavelength UV detector. The method is precise with relative standard deviations of 2.1, 0.6,1.9 and 1.6% respectively for the four compounds. The preservatives do not interfere with the method (98). 

Long, A.R. Hsieh, L.C. Malbrough, M.S. Short, C.R. Barker, S.A. A multiresidue method for the isolation and liquid chromatographic determination of seven sulfonamides in infant formula. J.Liq.Chromatogr., 1989, 12, 1601-1612 [extracted sulfadiazine, sulfadimethoxine, sulfamerazine, sulfamethazine, sulfathiazole, sulfisoxazole column temp 45 SPE]... 

Sulfonamides having a free j )-amino group are readily assayed by titration with nitrous acid. The sulfonamide function may also be titrated with base, such as lithium methoxide. The majority of the sulfas listed in the U.S. Pharmacopeia XXII, however, are assayed by chromatographic methods, particularly high performance liquid chromatography (49). Sulfonamides for which assays are listed in the U.S. Pharmacopeia XXII-National Formulary XVII include the following sulfacetamide, sulfabenzamide, sulfadiazine, sulfadoxine, sulfamerazine, sulfamethazine, sulfamethizole, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfathiazole, sulfinpyrazone, sulfis ox azole, sulfisoxazole acetyl, sulfisoxazole diolamine, sulfoxone, triple sulfa, dapsone, and various combinations with prednisolone, pyrimethamine, and trimethoprim. 

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. 

A spectrophotometric method for some sulfa drugs starts with the formation of an orange yellow colored azo product by the diazotization of sulfonamides and is followed by a coupling reaction with 3-aminophenol in aqueous medium. The absorbance of the resulting orange yellow azo product is measured at 460 nm and the product is stable for 6 days at 27°C. The method is successfully used for the determination in various pharmaceutical preparations of the sulfonamides dapsone, sulfathiazole, sulfadiazine. 

Another method for the determination of sulfa drugs is based on the formation of a violet-colored azo product by the diazotization of sulfonamides, followed by a coupling reaction with iminodibenzyl in alcohol medium. Absorbance of the resulting violet azo product is measured at 570-580 nm and is stable for 24 h at 27°C. Beer s law is obeyed in the concentration range of 0.05-6.0 ppm at the wavelength of maximum absorption. The method is successfully employed for the determination of sulfathiazole, sulfadiazine, sulfacetamide, sulfamethoxazole, sulfamerazine, sulfaguanidine, and sulfadimidine. The proposed reaction mechanism for the formation of the violet azo dye is shown in Figure 3. 

Sulfaguanidine, sulfadiazine, and succinyl sulfathiazole from a pharmaceutical powder were baseline resolved on a C,g column (A = 270nm) using a 20/80 methanol/water (50 mM ammonium acetate) mobile phase [508]. Elution was complete in 5 min and peak shapes were excellent. Twelve sulfonamides were well resolved on a C,g colunm (A = 254 nm) using an isocratic 6/94 IPA/water (20 mM sodium dodecylsullate [SDS] with phosphate buffer at pH 3.0) mobile phase. Elution was complete in 15 min. The effects of changing % IPA and SDS concentration on Id and a values were presented [509]. This study provides excellent background information for method development. Detection limits of 1 pg/mL were reported. 

Combs, M.T. Ashraf-Khorassani, M. Taylor, L.T. Method development for the separation of sulfonamides by supercritical fluid chromatography, J.Chromatogr.Sci., 1997,35,176-180. [sulfamethazine sulfamerazine sulfapyridine sulfadimethoxine sulfadisizine sulfaquinoxaline sulfachlorpyridazine sulfathiazole]... 

The SAS methods have been used for preparing a variety of particles and fine powders from proteins, pharmaceuticals, pigments, polymers, and even explosives. For example, Debenedetti and coworkers used a continuous-flow, supercritical antisolvent process to prepare fine powders of trypsin, lysozyme, and insulin proteins (58-60). In the preparation a protein solution in dimethyl-sulfoxide (DMSO) was sprayed through a small orifice into supercritical CO2. The particles had diameters ranging from 1 to 5 p,m. The biological activity of the micrometer-sized powders was nearly the same as that of the starting materials. The method has also been used in the processing of pharmaceutically important compounds, such as salmeterol xinafoate (61), sulfathiazole (62), and methylprednisolone and hydrocortisone acetate (41). Kitamura et al. used the... 

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