Rapid analysis of alkylphosphonate drugs by capillary zone electrophoresis using indirect ultraviolet detection

Abstract

A rapid capillary electrophoretic method for the analysis of three alkylphosphonate drugs (i.e. fosfomycin disodium (FOS), clodronate disodium (CLO) and alendronate sodium (ALN)) was developed by using multiple probe BGE and indirect UV detection. BGE containing 30 mM benzoic acid, 5 mM salicylic acid and 0.5 mM CTAB (pH 3.8), temperature of 30 degrees C, applied voltage of -30 kV and detection at 220 nm provided baseline separation of all analytes (resolution (R)>2.2) in 3.2 min. EOF reversal by addition of CTAB and negative voltage polarity leading to the co-EOF flow and short analysis time. Two probe BGE greatly improved peak symmetry. The method showed good linearity (r(2)>0.999 in ranges of 20-1000 microg/mL for FOS, 100-1000 microg/mL for CLO and 100-750 microg/mL for ALN) repeatablitiy (RSD<2.15%), recovery (99.3-101.1%) and sensitivity (LOD<50 microg/mL). Freshly prepared BGE and sample solutions are essential for the method precision and accuracy. This new method can be utilized for routine analysis of FOS, CLO and ALN in dosage forms because of its efficiency, reliability, speed and simplicity.

Analysis of alendronate in human urine and plasma by magnetic solid‐phase extraction and capillary electrophoresis with fluorescence detection

“…The LOD (S/N 3) and LOQ (S/N 10) for ALEN in both urine and plasma were 1.5 and 5 ng/mL, respectively. These LOD/LOQ values were more than three orders of magnitude lower than those reported using CE with direct or indirect UV detection, and were in the same order of magnitude as those reported using multidimensional CE−conductivity detection for urine analysis. In comparison to HPLC methods coupled with FL detection , electrochemical detection , MS and MS/MS detection in plasma and urine analyses, the developed CE‐FL method had a similar analytical sensitivity but simpler sample preparation procedure.…”

“…LOQs of ALEN in urine were about 3–10 ng/mL. Recently, a rapid CE‐indirect UV method for alkylphosphonate drugs including ALEN in dosage form was reported . Indirect UV detection of those non‐chromophore drugs was based on the use of multiple probes BGE.…”

Development and validation of a novel sensitive UV‐direct capillary electrophoresis method for quantification of alendronate in release studies from biomaterials

“…In this context, CE‐based methodologies might serve as useful alternatives for ALN quantitation, due to their high resolution, short analysis times, low sample and solvent consumption and adequate sensitivity. Few works have been reported about the use of CE for ALN determination, based either on indirect UV‐detection or direct UV‐detection after the formation of an ALN complex inside the capillary column or after a previous derivatization of ALN with naphthalene‐2,3‐dicarboxaldehyde (NDA) for fluorescence detection . To date, there have been no reports in the literature regarding either ALN quantification from complex drug delivery matrices such as the ones describes above or about CE‐methods based on ALN derivatization with OPA and 2‐ME for direct UV‐detection.…”

“…The CE cartridge temperature was kept at 35°C during runs, which offers best conditions for the stability of the ALN-derivatized compound, as it was reported recently [16]. The BGE consisted of 20 mM sodium borate buffer at pH 10, however different concentration ranges (10-50 mM) and pH values (7)(8)(9)(10)(11) were tested previously to achieve suitable conditions in terms of resolution, peak shape and adequate current. Therefore, 20 mM was set as the optimal concentration.…”

Zoledronate and Related Impurities Analysis by Capillary Zone Electrophoresis

“…Alternatively, a capillary zone electrophoresis (CZE) separation of ortho-, pyroand tripolyphosphate anions using a phthalate buffer pH 4.0 and indirect UV detection was also described [28]. Other developments involve the analysis of three alkylphosphonate drugs (fosfomycin disodium, clodronate disodium and alendronate sodium) by using an indirect UV detection with a BGE containing benzoic acid, salicylic acid and CTAB [29] or employed a Nitroso-R salt (1-nitroso-2-naphthol-3,6-disulphonic acid disodium salt) as background electrolyte with indirect UV detection of clodronate [30]. This work proposed a validated CE technique with indirect-UV detection, with low migration times and without sample preconcentration requirements, for the analysis of zoledronate and its related impurities, phosphite and phosphate.…”