The Thermo Scientific Vanquish UHPLC system was used for the assay and organic Impurities of minocycline Periodontal System. The analysis was performed on a Thermo Scientific Accucore XL-C8 HPLC column using the method described in the USP43-NF38 . The results obtained for resolution and tailing factor met the criteria stated in the USP43-NF38. The result obtained for resolution between the peaks due to epiminocylcine and minocycline was 4.8 (USP criteria of minimum 2.0 ).

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 assay and organic impurities analysis of minocycline hydrochloride. The analysis was performed on a Thermo Scientific Acclaim 120 C18 HPLC column using the method described in the USP 39 monograph. The results obtained for resolution and tailing factor met the criteria stated in the USP 39. The results obtained for resolution between epiminocycline and minocycline was 7.5 (USP criteria of NLT 4.6) and tailing factor of minocycline (0.5 mg/mL) was 0.94 (USP criteria of 0.9 to 2.0).

There is growing environmental concern regarding the health impact of trace levels of pharmaceuticals and personal care products (PPCPs) in water resources. In response, the U.S. Environmental Protection Agency (EPA) published Method 1694, which determines dozens of PPCPs in water, soil, sediment, and biosolids by HPLC-MS/MS. We demonstrate a progressive approach to analyzing PPCPs in environmental sources of water at the ng/L level with online sample preparation using small volumes of water, thus saving time and reducing the cost of analysis.