Simultaneous determination of metronidazole and tinidazole in plasma by using HPLC-DAD coupled with second-order calibration

RP-HPLC-DAD Method Development and Validation for Simultaneous Determination of Lansoprazole, Tinidazole, Amoxicillin and Naproxen in Their Raw Materials and Combined Dosage Form: DOE Approach for Optimization of the Proposed Method

BACKGROUND

Helicobacter pylori infection is a common cause of peptic ulcer disease and dyspepsia. In addition, it may result in gastric cancer and gastric mucosa associated lymphoid tissue lymphoma. First-line therapy usually is consisted of triple therapy containing Clarithromycin or Amoxicillin, one of the proton pump inhibitors and Metronidazole or Tinidazole. In addition to the triple therapy, an analgesic is required to relieve the pain such as; Naproxen.

OBJECTIVE

A sensitive and selective method need to be developed and validated for simultaneous determination of four drugs (Amoxacillin, Tinidazole, Naproxen and Lansoprazole) used for treating Helicobacter pylori in their combined dosage forms.

METHODS

With the aid of experimental design, the cited drugs were separated and quantified. HPLC with diode array detector was used and metronidazole was the internal standard which is one of the drugs used for that case also. A thermo Scientific BDS Hypersil C18 column (5 µm, 250 mm x 4.6 mm) with mobile phase composed of acetonitrile: water (40:60, v/v), pH = 5 adjusted with phosphoric acid at 30° C was used for the separation of the cited drugs.

RESULTS

The method was linear over concentration ranges 10-500 µg/mL for Amoxacillin, 10-350 µg/mL for Tinidazole, 10-250 µg/mL for Naproxen and 2-20 μg/mL for Lansoprazole. The proposed method was fully validated according to ICH guidelines. Statistical analysis revealed no significant difference between the results obtained and the four reference methods for investigated drugs.

CONCLUSION

The method can be easily implemented in quality control studies of the cited drugs in their dosage forms.

HIGHLIGHTS

Experimental design was applied using Plackett-Burman design for preliminary screening of factors followed by Box-Behnken design for chromatographic method optimization.

Preparation of reduced graphite oxide loaded with cobalt(II) and nitrogen co-doped carbon polyhedrons from a metal-organic framework (type ZIF-67), and its application to electrochemical determination of metronidazole

The integration of derivatives of granular metal-organic frameworks (MOFs) and an electrically conductive carbon substrate is an effective way to circumvent the deficiency of powdered pristine MOFs or MOF-derived carbon in practical application. The authors describe the use of graphite oxide (GO) as a substrate for in-situ assembly with the zeolitic imidazole framework ZIF-67. The GO and ZIF-67 composites were converted, via pyrolysis, into reduced graphite oxide loaded with Co/N-co-doped carbon polyhedrons (ZIF-67C@rGO). By using various amounts of GO, a series of ZIF-67C@rGO-x with different fractions of GO were synthesized and utilized as electrode modifiers for the detection of the antibiotic metronidazole (MNZ). The results revealed that the ZIF-67C@rGO-0.06 display best sensing performance. This is likely to be due to its hierarchically open pores, abundant active sites and good electrical conductivity. The sensor, best operated near a working potential around -0.6 V (vs. SCE), has a linear response in the 0.5 to 1000 μM MNZ concentration range and a 0.05 μM detection limit. The sensor was applied to the analysis of pharmaceutical samples where it showed excellent selectivity, good repeatability and satisfying recoveries. Graphical abstract Schematic representation of preparation and application of ZIF-67C@rGO-x.

Development and Optimization of HPLC Analysis of Metronidazole, Diloxanide, Spiramycin and Cliquinol in Pharmaceutical Dosage Forms Using Experimental Design

A new simple, sensitive, rapid and accurate gradient reversed-phase high-performance liquid chromatography with photodiode array detector (RP-HPLC-DAD) was developed and validated for simultaneous analysis of Metronidazole (MNZ), Spiramycin (SPY), Diloxanidefuroate (DIX) and Cliquinol (CLQ) using statistical experimental design. Initially, a resolution V fractional factorial design was used in order to screen five independent factors: the column temperature (°C), pH, phosphate buffer concentration (mM), flow rate (ml/min) and the initial fraction of mobile phase B (%). pH, flow rate and initial fraction of mobile phase B were identified as significant, using analysis of variance. The optimum conditions of separation determined with the aid of central composite design were: (1) initial mobile phase concentration: phosphate buffer/methanol (50/50, v/v), (2) phosphate buffer concentration (50 mM), (3) pH (4.72), (4) column temperature 30°C and (5) mobile phase flow rate (0.8 ml min^-1). Excellent linearity was observed for all of the standard calibration curves, and the correlation coefficients were above 0.9999. Limits of detection for all of the analyzed compounds ranged between 0.02 and 0.11 μg ml^-1; limits of quantitation ranged between 0.06 and 0.33 μg ml^-1 The proposed method showed good prediction ability. The optimized method was validated according to ICH guidelines. Three commercially available tablets were analyzed showing good % recovery and %RSD.

Simultaneous determination of some antiprotozoal drugs in different combined dosage forms by mean centering of ratio spectra and multivariate calibration with model updating methods

BACKGROUND

Metronidazole (MET) and Diloxanide Furoate (DF), act as antiprotozoal drugs, in their ternary mixtures with Mebeverine HCl (MEH), an effective antispasmodic drug. This work concerns with the development and validation of two simple, specific and cost effective methods mainly for simultaneous determination of the proposed ternary mixture. In addition, the developed multivariate calibration model has been updated to determine Metronidazole benzoate (METB) in its binary mixture with DF in Dimetrol® suspension.

RESULTS

Method (I) is the mean centering of ratio spectra spectrophotometric method (MCR) that depends on using the mean centered ratio spectra in two successive steps that eliminates the derivative steps and therefore the signal to noise ratio is enhanced. The developed MCR method has been successfully applied for determination of MET, DF and MEH in different laboratory prepared mixtures and in tablets. Method (II) is the partial least square (PLS) multivariate calibration method that has been optimized for determination of MET, DF and MEH in Dimetrol ® tablets and by updating the developed model, it has been successfully used for prediction of binary mixtures of DF and Metronidazole Benzoate ester (METB) in Dimetrol ® suspension with good accuracy and precision without reconstruction of the calibration set.

CONCLUSION

The developed methods have been validated; accuracy, precision and specificity were found to be within the acceptable limits. Moreover results obtained by the suggested methods showed no significant difference when compared with those obtained by reported methods. GRAPHICAL