The Thermo Scientific Dionex UltiMate 3000 LC system is applied for the related substances analysis of Sulfamethoxazole. The analysis was performed on a Thermo Scientific Syncronis C8 HPLC column using the method described in the EP-8.0 monograph. The results obtained for peak resolution and relative retention times exceeded the criteria stated in the EP. Resolution between sulfamethoxazole and Impurity-A was 5.7 (EP criteria of not less than 3.5).

The Thermo Scientific Dionex UltiMate 3000 LC system is applied for the related substances analysis of Sulfacetamide Sodium. The analysis was performed on a Thermo Scientific Syncronis aQ HPLC column using the method described in the EP 8.0. The results obtained for resolution met the criteria stated in the EP. The results obtained for resolution between the peaks due to Impurity A and sulfacetamide was 14.5 (EP criteria of minimum 5.0).

The Thermo Scientific Dionex UltiMate 3000 LC system is applied for the related substances analysis of Cefotaxime Sodium. The analysis was performed on a Thermo Scientific Syncronis aQ HPLC column using the method described in the EP 8.0. The results obtained for resolution and symmetry factor met the criteria stated in the EP. The results obtained for resolution between the peaks due to Impurity E and Cefotaxime was 6.7 (EP criteria of minimum 3.5) and asymmetry factor for cefotaxime was 1.1 (EP criteria of maximum 2).

The Thermo Scientific Dionex UltiMate 3000 LC system is applied for the assay and related substances analysis of minocycline hydrochloride. The analysis was performed on a Thermo Scientific Hypersil GOLD C8 HPLC column using the method described in the EP 8.0. The results obtained for resolution and theoretical plates met the criteria stated in the EP. The results obtained for resolution between the peaks due to impurity A and minocycline was 4.3 (EP criteria of minimum 2.0) and theoretical plates for minocycline (0.125 mg/mL) was 6376 (EP criteria of minimum 3000).

The Thermo Scientific Dionex UltiMate 3000 LC system is applied for the related substances analysis of cefaclor. The analysis was performed on a Thermo Scientific Syncronis C18 HPLC column using the method described in the EP 8.0 and JP XVI. The results obtained for resolution and theoretical plates met the criteria stated in the EP/JP. The results obtained for resolution between the peaks due to cefaclor and EP Impurity D was 11.1 (EP criteria of minimum 2.0) and theoretical plates for cefaclor was 1,12,359 (JP criteria of minimum 40,000).