Liquid Chromatographic Analysis of Cephalexin in Human Plasma by Fluorescence Detection of the 9-Fluorenylmethyl Chloroformate Derivative

Simultaneous Quantification of Cephalexin and Sodium Benzoate in their Dosage forms by high analytical technique. Application of Lean Six Sigma and In-Vitro Dissolution studies

OBJECTIVES

The aim of the present work is to develop and validate a novel and simple Chromatographic and MCR methods for simultaneous quantification of cephalexin (CPH) and sodium benzoate (SDM) in their dosage form and application of Lean Six Sigma (LSS) to reduce variation and improve quality.

METHODS

Isocratic separation is performed using Agilent XDB-C8 (4.6mm×250mm) 5μm, with a mobile phase consisting of acetonitrile: water (30: 70, v/v) containing 0.1% orthophosphoric acid (OPA) at flow rate of 1.5mL/min and wavelength 254nm with injection volume of 20μL for HPLC and Agilent ZORBAX SB-C18 column (50mm×2.1mm, 1.8μm particle size) at flow rate 0.25mL/min, injection volume 0.8μL for UPLC. MCR spectrophotometric method is successfully applied for resolving spectral overlap of drugs at 240nm and 250nm for CPH and SDM, respectively. Comparative invitro dissolution studies are established on Generic product; Rivalexin and Lexin 250mg/5mL, consequently it had been considered equivalent and like the innovator product; Cephalexin USP 250mg/5mL using different USP media.

RESULTS

Good Linearity and recovery are achieved over the concentration range of 10-300, and 5-50μg/mL for the studied drugs. Process Capability Index (Cpk) is >1.33 and still capable during all stages of the product release.

CONCLUSION

The proposed method is accurate and could be applied to dosage form and LSS to interpret the data of quality attributes.

Determination of trace amino acids in human serum by a selective and sensitive pre-column derivatization method using HPLC-FLD-MS/MS and derivatization optimization by response surface methodology

Analysis of trace amino acids (AA) in physiological fluids has received more attention, because the analysis of these compounds could provide fundamental and important information for medical, biological, and clinical researches. More accurate method for the determination of those compounds is highly desirable and valuable. In the present study, we developed a selective and sensitive method for trace AA determination in biological samples using 2-[2-(7H-dibenzo [a,g]carbazol-7-yl)-ethoxy] ethyl chloroformate (DBCEC) as labeling reagent by HPLC-FLD-MS/MS. Response surface methodology (RSM) was first employed to optimize the derivatization reaction between DBCEC and AA. Compared with traditional single-factor design, RSM was capable of lessening laborious, time and reagents consumption. The complete derivatization can be achieved within 6.3 min at room temperature. In conjunction with a gradient elution, a baseline resolution of 20 AA containing acidic, neutral, and basic AA was achieved on a reversed-phase Hypersil BDS C(18) column. This method showed excellent reproducibility and correlation coefficient, and offered the exciting detection limits of 0.19-1.17 fmol/μL. The developed method was successfully applied to determinate AA in human serum. The sensitive and prognostic index of serum AA for liver diseases has also been discussed.