Simultaneous Determination of Paracetamol and Orphenadrine Citrate in Dosage Formulations and in Human Serum by RP-HPLC

Exploitation of multi-walled carbon nanotubes/Cu(ii)-metal organic framework based glassy carbon electrode for the determination of orphenadrine citrate

Metal organic frameworks (MOFs), with structural tunability, high metal content and large surface area have recently attracted the attention of researchers in the field of electrochemistry. In this work, an unprecedented use of multi-walled carbon nanotubes (MWCNTs)/copper-based metal-organic framework (Cu-BTC MOF) composite as an ion-to-electron transducer in a potentiometric sensor is proposed for the determination of orphenadrine citrate. A comparative study was conducted between three proposed glassy carbon electrodes, Cu-MOF, (MWCNTs) and MWCNTs/Cu-MOF composite based sensors, where Cu-MOF, MWCNTs and their composite were utilized as the ion-to-electron transducers. The sensors were developed for accurate and precise determination of orphenadrine citrate in pharmaceutical dosage form, spiked real human plasma and artificial cerebrospinal fluid (ACSF). The sensors employed β-cyclodextrin as a recognition element with the aid of potassium tetrakis(4-chlorophenyl)borate (KTpCIPB) as a lipophilic ion exchanger. The sensors that were assessed based on the guidelines recommended by IUPAC and demonstrated a linear response within the concentration range of 10-7 M to 10-3 M, 10-6 M to 10-2 M and 10-8 M to 10-2 M for Cu-MOF, MWCNTs and MWCNTs/Cu-MOF composite based sensors, respectively. MWCNTs/Cu-MOF composite based sensor showed superior performance over other sensors regarding lower limit of detection (LOD), wider linearity range and faster response. The sensors demonstrated their potential as effective options for the analysis of orphenadrine citrate in quality control laboratories and in different healthcare activities.

Fast determination of codeine, orphenadrine, promethazine, scopolamine, tramadol, and paracetamol in pharmaceutical formulations by capillary electrophoresis

Paracetamol is an active ingredient commonly found in pharmaceutical formulations in combination with one of the following compounds: codeine, orphenadrine, promethazine, scopolamine, and tramadol. In this work, we propose a unique analytical method for determination of these active ingredients in pharmaceutical samples. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation was achieved on a fused silica capillary (50 cm total length, 40 cm effective length, and 50 μm id) using an optimized background electrolyte composed of 20 mmol/L β-alanine/4 mmol/L sodium chloride/4 μmol/L sodium hydroxide (pH 9.6). Each sample can be analyzed in a single run (≤2 min) and the limits of detection were 2.5, 0.62, 0.63, 2.5, 15, and 1.6 μmol/L for scopolamine, tramadol, orphenadrine, promethazine, codeine, and paracetamol, respectively. Recovery values for spiked samples were between 94 and 104%.

Application of normalized spectra in resolving a challenging Orphenadrine and Paracetamol binary mixture

Normalized spectra have a great power in resolving spectral overlap of challenging Orphenadrine (ORP) and Paracetamol (PAR) binary mixture, four smart techniques utilizing the normalized spectra were used in this work, namely, amplitude modulation (AM), simultaneous area ratio subtraction (SARS), simultaneous derivative spectrophotometry (S(1)DD) and ratio H-point standard addition method (RHPSAM). In AM, peak amplitude at 221.6nm of the division spectra was measured for both ORP and PAR determination, while in SARS, concentration of ORP was determined using the area under the curve from 215nm to 222nm of the regenerated ORP zero order absorption spectra, in S(1)DD, concentration of ORP was determined using the peak amplitude at 224nm of the first derivative ratio spectra. PAR concentration was determined directly at 288nm in the division spectra obtained during the manipulation steps in the previous three methods. The last RHPSAM is a dual wavelength method in which two calibrations were plotted at 216nm and 226nm. RH point is the intersection of the two calibration lines, where ORP and PAR concentrations were directly determined from coordinates of RH point. The proposed methods were applied successfully for the determination of ORP and PAR in their dosage form.

Selective spectrophotometric methods for determination of ternary mixture with overlapping spectra: a comparative study

Comparable double divisor ratio spectra derivative, area under curve of derivative ratio and mean centering of ratio spectra spectrophotometric methods were introduced for determination of orphenadrine citrate (ORPH), caffeine (CAF) and aspirin (ASP); a combination for symptomatic relief of mild to moderate pain of acute musculoskeletal disorders; with evident accuracy and precision. The suggested methods have the advantage over the previously published spectrophotometric method for determination of the same combination in that they did not require a preliminary separation step and able to resolve the ternary mixture, with severe overlapping spectra, with competent sensitivity and selectivity. The recommended methods allow the determination of ORPH, CAF and ASP in the range of 2-32, 2-28 and 3-28 μg mL(-1), respectively. The validity of the proposed methods was examined by analysis of different laboratory prepared mixtures of ORPH, CAF and ASP and assay of their tablet formulation where reliable results were obtained. Statistical analysis between the suggested spectrophotometric methods and the reported HPLC method using student's-t and F-ratio tests reveals that the suggested methods are as accurate and precise as the reported one.

Development of a capillary electrophoresis method for the determination of orphenadrine citrate in tablets in the presence of paracetamol

A validated method using capillary electrophoresis was developed, for the determination of orphenadrine citrate in its tablet formulations, in the presence of paracetamol. The method employs a running buffer of 30 mM pentane sulfonate sodium, dissolved in 20 mM MOPS buffer pH 7.7. Samples were injected using hydrodynamic sample injection mode (25 mbar, for 25 s), using positive polarity of 25 kV, at a constant temperature of 30 °C. Samples of orphenadrine citrate alone or in mixture solutions with paracetamol were exposed to various degradation conditions, and were electrophoresed using the recommended condition. The method was found to be specific, linear (r (2) = 0.994), precise, accurate, and robust, with an LOQ of 0.02 mg/mL. The proposed method was successfully applied for measurement of the percentage per label of orphenadrine citrate in commercially available tablets.