Simultaneous determination of selected ionophoric coccidiostats and amino acids in feed premixes using high-performance liquid chromatography-ultraviolet detection method

The combination of ionophoric coccidiostats and amino acids (AAs) is important in poultry feeding to enhance immunity and improve the growth and feed efficiency of birds suffering from coccidiosis. A simple, rapid, and economical high-performance liquid chromatography-ultraviolet detection (HPLC-UV) method for the simultaneous determination of three ionophoric coccidiostats, namely salinomycin (SAL), maduramicin (MAD), and monensin (MON) in addition to three AAs; L-tryptophan (L-TRP), alpha-ketoleucin (KLEU), and L-valine (L-VAL) in feed premixes was developed and validated. Chromatographic separation was achieved in less than 12 min using a phenyl hexyl column with a mobile phase consisting of acetonitrile/methanol/water (25:20:55, v/v/v) adjusted to pH 3 using phosphoric acid. Isocratic elution was performed at a flow rate of 1 mL/min with UV detection at 210 nm. The method showed good linearity in the ranges 0.50-5.0 mg/mL for MON, 0.20-2.0 mg/mL for MAD and SAL, 10.0-100.0 μg/mL for L-TRP and KLEU, and 50.0-500.0 μg/mL for VAL. The developed method was successfully applied to determine the studied analytes in feed premixes with good recoveries and precision. The good validation criteria of the proposed method allow its utilization in quality control laboratories.

Green versatile micellar electrokinetic chromatographic method for determination of six antimicrobial and anti-inflammatory drugs in combined dosage forms

A fast reliable micellar electrokinetic methodology was investigated for the concurrent quantitation of six antimicrobial and anti-inflammatory drugs, namely, ciprofloxacin, dexamethasone, metronidazole, ornidazole, spiramycin and tinidazole. The method has the merits of rapidity, precision, and sensitivity. The separation was carried out in less than 7 min by applying a basic background electrolyte consisting of 25 mM disodium tetraborate buffer, pH 9 containing 50 mM SDS at 25 kV using photodiode array detector at 230 and 315 nm. The internal standard used during analysis was cromolyn sodium and validation was carried out following ICH guidelines. The proposed method showed linear response over the range from 0.5 to 10.0 μg mL−1 reaching limits of detection and limits of quantitation in the ranges of 0.09–0.2 μg mL−1 and 0. 27–0.6 respectively. The method's greenness was estimated using the GAPI tool where excellent greenness was concluded. Co-formulated or single-ingredient commercial preparations were investigated and the results were statistically evaluated.

Novel spectrofluorimetric technique for determination of amoxicillin and ethopabate in chicken tissues, liver, kidney, eggs, and feed premix

A new smart spectrofluorometric method was developed for the quantitation of amoxicillin and ethopabate simultaneously for the first time. The method is based on measuring their first derivative synchronous amplitudes in water at Δλ = 80 nm. The peak amplitudes were recorded at their crossing points; 240 nm for amoxicillin and 280 nm for ethopabate. The method is linear over the concentration ranges of 100.0-1,000.0 ng/ml for amoxicillin and 2.0-20.0 ng/ml for ethopabate. The limits of detection were 20.0 ng/ml and 0.58 ng/ml and limits of quantitation were 60.0 ng/ml and 1.92 ng/ml for amoxicillin and ethopabate, respectively. The method sensitivity permitted the determination of the two drugs below their maximum residue limit stated by the federal regulations. The developed method was applicable to the analysis of both drugs in the veterinary powders, feed premix, chicken tissues, liver, kidney, and eggs samples with percentage recoveries ranging 93.72-104.71%.

Rapid micellar HPLC analysis of loratadine and its major metabolite desloratadine in nano-concentration range using monolithic column and fluorometric detection: application to pharmaceuticals and biological fluids

Background

Loratadine is a commonly used selective non-sedating antihistaminic drug. Desloratadine is the active metabolite of loratadine and, in addition, a potential impurity in loratadine bulk powder stated by the United States Pharmacopeia as a related substance of loratadine. Published methods for the determination of both analytes suffer from limited throughput due to the time-consuming steps and tedious extraction procedures needed for the analysis of biological samples. Therefore, there is a strong demand to develop a simple rapid and sensitive analytical method that can detect and quantitate both analytes in pharmaceutical preparations and biological fluids without prior sample extraction steps.

Results

A highly-sensitive and time-saving micellar liquid chromatographic method is developed for the simultaneous determination of loratadine and desloratadine. The proposed method is the first analytical method for the determination of this mixture using a monolithic column with a mobile phase composed of 0.15 M sodium dodecyl sulfate, 10% n-Butanol and 0.3% triethylamine in 0.02 M phosphoric acid, adjusted to pH 3.5 and pumped at a flow rate of 1.2 mL/min. The eluted analytes are monitored with fluorescence detection at 440 nm after excitation at 280 nm. The developed method is linear over the concentration range of 20.0–200.0 ng/mL for both analytes. The method detection limits are 15.0 and 13.0 ng/mL and the limits of quantification are 20.0 and 18.0 ng/mL for loratadine and desloratadine, respectively. Validation of the developed method reveals an accuracy of higher than 97% and intra- and inter-day precisions with relative standard deviations not exceeding 2%.

Conclusions

The method can be successfully applied to the determination of both analytes in various matrices including pharmaceutical preparations, human urine, plasma and breast milk samples with a run-time of less than 5 min and without prior extraction procedures. The method is ideally suited for use in quality control laboratories. Moreover, it could be a simple time-saving alternative to the official pharmacopeial method for testing desloratadine as a potential impurity in loratadine bulk powder.Graphical abstract