RP-LC simultaneous quantitation of co-administered drugs for (non-insulin dependent) diabetic mellitus induced dyslipidemia in active pharmaceutical ingredient, pharmaceutical formulations and human serum with UV-detector.

Background: Rapid, efficient and accurate RP-HPLC-UV method for the simultaneous determination and quality control of active pharmaceutical ingredient (API), pharmaceutical formulations and human serum containing drugs as rosuvastatin together with metformin, glimepiride and gliquidone has been proposed.

Methods: The chromatographic system comprised mobile phase of methanol:water 90:10 v/v; pH adjusted to 3.0 with o-phosphoric acid, at 1 ml/min through Prepacked Purospher Star C18 (5 μm, 25×0.46 cm) column with UV detection at isosbestic point 231 nm.

Results: The method showed good linearity in the range 0.25-25 μg/ml for metformin and 0.5-50 μg/ml for rosuvastatin, glimepiride and gliquidone with correlation co-efficient ≥ 0.998; (precision %RSD<2) for all drugs in API, formulations and human serum. The recovery of all drugs was 98.9-101.91% in API and formulations and 99.92-102.08% in human serum. The sensitivity of method increased when drugs were analyzed after programming the detector at their individual λmax where their LODs shifted down to 5, 3, 10 and 9 ng/ml from 10, 17, 15 and 14 ng/ml when calculated at their isosbestic point respectively at least concentration 0.125 μg/ml for metformin and 0.25 μg/ml for rosuvastatin, glimepiride and gliquidone with correlation co-efficient ≥ 0.998 in each case.

Conclusions: The proposed drugs can be analyzed by this method for routine analysis and clinical studies with sensitivity at nanoscale with small sample volume.