Sulfacetamide

Validation of a stability-indicating spectrometric method for the determination of sulfacetamide sodium in pure form and ophthalmic preparations

“…SC and its degradation product, SN, at pH 7.0 exhibit absorption maxima at 260 and 259 nm, respectively. [ 9 ] However, at pH 4.0 (acetate buffer), the absorption maximum of SC (271 nm) is quite distinct from that of SN (258 nm) [ Figure 1 ]. This is due to difference in the ionization behavior of SC (p K a 5.40) and SN (p K a 10.45).…”

“…This is due to difference in the ionization behavior of SC (p K a 5.40) and SN (p K a 10.45). [ 9 ] Therefore, it is possible to conduct a two-component spectrometric assay of SC and SN by absorbance measurements at 271 and 258 nm. This method has been applied for the assay of SC sodium in thermal and photodegraded solutions containing SN as the only degradation product as well as in synthetic mixtures containing both compounds.…”

“…However, on prolonged light exposure (at least for 200 h at 70°C–90°C), SN is known to be further photo-oxidized to azobenzene-4,4-disulfoxamide which exhibits absorption maxima at 320 nm. [ 9 13 14 15 ] Therefore, the current method should be applied to the samples stored in the dark or not exposed to light for prolonged period or undergone thermal degradation without any interference from the photoproducts of SN.…”

“…SN is the major degradation product of SC. [ 9 13 14 15 29 30 31 ] However, its antibacterial activity is comparatively weaker than the parent compound, thus limiting its clinical use. [ 3 ] It has been observed that the current method of analysis can accurately and precisely determine both SC and SN in a mixture using the two-component analysis.…”

“…The methods for the assay of sulfonamides have been reviewed by Higuchi and Hanssen[ 8 ] and Ahmad et al . [ 9 ] The methods used for the assay of sulfonamides include chromatography,[ 10 11 12 ] spectrometry,[ 13 14 15 16 ] electrochemical techniques,[ 5 6 17 ] thermal techniques,[ 18 ] electrophoresis,[ 19 ] chemiluminescence detection,[ 20 ] supported liquid membrane extraction. [ 21 ]…”