Coulometric titration of urea with electrogenerated hypobromite.

A definitive method is described for the indirect assay of several tens of milligrams of urea by coulometric titration. Urea was decomposed in concentrated sulfuric acid using a Kjeldahl flask. Subsequently, the formed ammonium ion was titrated with electrogenerated hypobromite ion in a sodium bromide-sodium tetraborate medium of pH 8.

Preparation and evaluation of novel directly-compressed fast-disintegrating furosemide tablets with sucrose stearic acid ester.

Fast-disintegrating tablets of furosemide (FS) were prepared by the novel direct compression method. FS, microcrystalline cellulose (MC), croscarmellose sodium (CC), xylitol (XL) and sucrose stearic acid esters (SSEs) with an hydrophilic-lipophilic balance (HLB) of 16, 15 and 11, named S1670, S1570 and S1170, were used. An FS/SSE/MC mixed powder was obtained by solvent evaporation of a suspension of MC in ethanol solution containing FS and SSE, and the resultant mixed powder was mixed with CC and XL, and directly compressed.

Development of novel fast-disintegrating tablets by direct compression using sucrose stearic acid ester as a disintegration-accelerating agent.

It was attempted to produce novel furosemide (FS) fast-disintegrating tablets by direct compression. The combination of FS, microcrystalline cellulose, croscarmellose sodium and xylitol was used as the basic formulation, and sucrose stearic acid ester (SSE) was chosen as an additional additive. The tablets with SSE were prepared by the simple addition of SSE, using a lyophilized mixture of FS and SSE or using a FS/SSE mixture obtained by evaporation of their ethanol solution.