An Ultra-Sensitive and Selective LC-UV Method for the Simultaneous Determination of Pravastatin, Diltiazem, Naproxen Sodium and Meloxicam in API, Pharmaceutical Formulations and Human Serum

Abstract

Abstract:The aim of the present work was to develop a sensitive liquid chromatographic method for the quantitation of pravastatin and diltiazem along with naproxen and meloxicam using ultraviolet detector. The separation of components was achieved on Purospher Star, C 18 (5 µm, 25 x 0.46 cm) column using methanol-water (80:20 v/v) as mobile phase and pH adjusted 3.4 with 85% o-phosphoric acid. Related parameters that may influence the enrichment efficiency of speration of drugs such as the kind and volume of elute, sample flow rate, sample pH, and volume of the drug samples were investigated. Detection was performed at ambient temperature at 220 nm by pumping the mobile phase at the flow rate 1.0 mL min -1 . The experimental results indicated a good linearity (R 2 > 0.9947) over the concentration range of 0.5-20 µg mL -1 for pravastatin, naproxen and meloxicam and 0.75-24 µg mL -1 for diltiazem. The method was compared by programming the detector adjusting the wavelength with time to match the individual analyte's chromophore which enhanced sensitivity with linear range 0.25-8.0, 0.5-16, 0.4-12 and 0.2-4.0 µg mL -1 for pravastatin, diltiazem, naproxen and meloxicam respectively. The LOD values shifted down from 33, 70, 50 and 80 ng mL -1 to 15, 42, 20 and 10 ng mL -1 for pravastatin, diltiazem, naproxen and meloxicam respectively. Validation of the method showed good precision and accuracy for the proposed method. All the results indicated that this procedure could allow the simultaneous determination of these four compounds in API, pharmaceutical formulations and serum at trace levels. The method can be successfully applied for the determination of these drugs in human serum, clinical laboratories and in pharmaceutical formulations without diode array detector and without interference of excipients or endogenous components of serum.

Validated HPLC‐UV method for determination of naproxen in human plasma with proven selectivity against ibuprofen and paracetamol

“…Sample pretreatment in the previous studies was based on solid‐phase extraction (Gopinath et al ., ; Patel et al ., ), protein precipitation (Bae et al ., ; Elsinghorst et al ., ; Helmy and El Bedaiwy, ; Martín et al ., ; Palma‐Aguirre et al ., ; Sakaguchi et al ., ; Sultana et al ., ; Xiong et al ., ) and liquid–liquid extraction (Carrasco‐Portugal et al ., ; Marzo et al ., ; Niazi et al ., ; Setiawati et al , ; Shimek et al ., ; Sun et al ., ; Yilmaz et al ., ; Toothaker et al ., ). Solid‐phase extraction methods are very effective and provide a selective cleanup, but they require the use of expensive instruments and cartridges.…”

“…Therefore, contrary to previously reported assays (Helmy and El Bedaiwy, ; Martín et al ., ; Niazi et al ., ; Palma‐Aguirre et al ., ; Sun et al ., ), it is suitable for analyzing a large number of samples in a short time (1000 samples during about 6 days). The method presents a good linearity over the range of 0.50–80.00 µg/mL, which in opposite to results in earlier papers (Bae et al ., ; Martín et al ., ; Marzo et al ., ; Palma‐Aguirre et al ., ; Sultana et al ., ; Yilmaz et al ., ), and is appropriate for pharmacokinetic studies of 220 mg naproxen sodium dose. The diameter of the particles in the selected Zorbax SB‐C 18 column is lower than that in the previously reported method (Palma‐Aguirre et al ., ), which improved column efficiency.…”

“…Therefore, the mobile phase consisting of acetonitrile and 1.8 mM phosphoric acid used in this study provides an advantage for analyzing large numbers of samples. Sample pretreatment in the previous studies was based on solid-phase extraction (Gopinath et al, 2013;Patel et al, 2012), protein precipitation (Bae et al, 2009;Elsinghorst et al, 2011;Helmy and El Bedaiwy, 2013;Martín et al, 1999;Palma-Aguirre et al, 2009;Sakaguchi et al, 2011;Sultana et al, 2013;Xiong et al, 2008) and liquid-liquid extraction (Carrasco-Portugal et al, 2006;Marzo et al, 1997;Niazi et al, 1997;Setiawati et al, 2009; Figure 5. Chromatogram of the clinical sample drawn 0.5 h following the oral administration of 220 mg of naproxen sodium.…”

“…The majority of methods for naproxen quantification in human plasma or serum samples are based on high‐performance liquid chromatography technique (HPLC) with various detections, such as chemiluminescent (Xiong et al ., ), fluorometric (Sakaguchi et al ., ; Shimek et al ., ; Toothaker et al ., ), mass spectrometric (Choi et al ., ; Elsinghorst et al ., ; Gopinath et al ., ; Patel et al ., ) and the most common ultraviolet (UV) (Bae et al ., ; Carrasco‐Portugal et al ., ; Helmy and El Bedaiwy, ; Martín et al ., ; Marzo et al ., ; Niazi et al ., ; Palma‐Aguirre et al ., ; Setiawati et al ., ; Sultana et al ., ; Sun et al ., ; Yilmaz et al ., ). For the HPLC‐UV assays the lowest reported lower limit of quantitation (LLOQ) value is 100 ng/mL (Sun et al ., ; Yilmaz et al ., ).…”

“…The previously presented HPLC-UV assays have several limitations. Many of them have linearity ranges inapplicable for the planned dose of 220 mg (Bae et al, 2009;Martín et al, 1999;Marzo et al, 1997;Palma-Aguirre et al, 2009;Sultana et al, 2013;Yilmaz et al, 2014). Additionally, owing to long chromatographic run times, some of these methods are not capable of analyzing a large number of samples in a short time (Helmy and El Bedaiwy, 2013;Martín et al, 1999;Niazi et al, 1997;Palma-Aguirre et al, 2009;Sun et al, 2003).…”