Simultaneous determination of chlordiazepoxide and clidinium bromide in pharmaceutical formulations by derivative spectrophotometry

Evaluation of the Efficiency of Smart Stability-Indicating Spectrophotometric Methods Based on Mathematical and Statistical Processing of the Obtained Results Via Different Manipulating Pathways

Background:

Smart different stability-indicating spectrophotometric methods have been established for the assay of chlordiazepoxide and clidinium bromide without the intervention of alkaline degradate of clidinium via various and different manipulating pathways without previous separation steps.

Objective:

The specificity of the established methods was inspected by analysing mixtures of cited drugs in the existence of the alkali-induced degradation product.

Methods:

These methods were employed either on scanned zero-order absorption spectra using absorbance subtraction, dual wavelength and Q-absorbance ratio or the amplitudes of the ratio spectra of zero-order absorption spectra like amplitude modulation and by derivative techniques to the ratio spectra as a derivative ratio method. In addition, the absorbance of the recovered zero-order absorption spectra was applied by successive ratio subtraction coupled with constant multiplication. Finally, the pathway depends on the amplitudes of the derivative spectra, successive derivative subtraction coupled with constant multiplication. The ranges of linearity were (1-12µg/mL) for chlordiazepoxide and (3- 12µg/mL) for clidinium bromide.

Results:

The outcomes achieved by the prospective methods were in consent with those of the official and reported methods when statistically compared using student’s t test, F-test and one-way ANOVA where no significant difference was detected with suitable precision, proving the absence of any important difference in accuracy and precision between them. They were confirmed in accordance with International Conference on Harmonization guidelines.

Conclusion:

The established methods can be considered as alternative methods for the routine determination of this fixed dose combination with minimum sample preparation.

Simultaneous HPLC Determination of Chlordiazepoxide and Mebeverine HCl in the Presence of Their Degradation Products and Impurities

A simple, rapid, and sensitive RP-HPLC method was developed and validated for the simultaneous determination of chlordiazepoxide (CDO) and mebeverine HCl (MBV) in the presence of CDO impurity (2-amino-5-chlorobenzophenone, ACB) and MBV degradation product (veratric acid, VER). Separation was achieved within 9 min on a BDS Hypersil phenyl column (4.5 mm × 250 mm, 5 µm particle size) using a mobile phase consisting of acetonitrile: 0.1 M potassium dihydrogen phosphate: triethylamine (35 : 65 : 0.2, v/v/v) in an isocratic mode at a flow rate of 1 mL/min. The pH of the mobile phase was adjusted to 4.5 with orthophosphoric acid and UV detection was set at 260 nm. A complete validation procedure was conducted. The proposed method exhibited excellent linearity over the concentration ranges of 1.0–100.0, 10.0–200.0, 2.0–40.0, and 2.0–40.0 µg/mL for CDO, MBV, VER, and ACB, respectively. The proposed method was applied for the simultaneous determination of CDO and MBV in their coformulated tablets with mean percentage recoveries of 99.75 ± 0.62 and 98.61 ± 0.38, respectively. The results of the proposed method were favorably compared with those of a comparison HPLC method using Studentt-test and the variance ratioF-test. The chemical structure of MBV degradation product was ascertained by mass spectrometry and IR studies.

Analytical methods for determination of benzodiazepines. A short review

Benzodiazepines (BDZs) are generally commonly used as anxiolytic and/or hypnotic drugs as a ligand of the GABAA-benzodiazepine receptor. Moreover, some of benzodiazepines are widely used as an anti-depressive and sedative drugs, and also as anti-epileptic drugs and in some cases can be useful as an adjunct treatment in refractory epilepsies or anti-alcoholic therapy. High-performance liquid chromatography (HPLC) methods, thin-layer chromatography (TLC) methods, gas chromatography (GC) methods, capillary electrophoresis (CE) methods and some of spectrophotometric and spectrofluorometric methods were developed and have been extensively applied to the analysis of number of benzodiazepine derivative drugs (BDZs) providing reliable and accurate results. The available chemical methods for the determination of BDZs in biological materials and pharmaceutical formulations are reviewed in this work.

Simultaneous Determination of Clidinium Bromide and Chlordiazepoxide in Combined Dosage Forms by High-Performance Liquid Chromatography

A sensitive and precise RP-HPLC method has been developed for the simultaneous estimation of clidinium bromide (CDB) and chlordiazepoxide (CDZ) in pure and pharmaceutical formulations. The separation was achieved on a Nucleodur C₈ (250 × 4.6 mm i.d., 5 μm particle size) column at 25°C. CH₃CN-MeOH-NH₄OAc 0.1M (30 : 40 : 30, v/v/v) was used as the mobile phase at a flow rate of 1.0 mL min⁻¹ and detector wavelength at 218 nm. Almotriptan (ALT) was used as internal standard. The validation of the proposed method was carried out for linearity, accuracy, precision, LOD, LOQ, and robustness. The method showed good linearity in the ranges of 2.5–300.0 and 3.0–500.0 μg mL⁻¹ for CDB and CDZ, respectively. The percentage recovery obtained for CDB and CDZ was 100.40–103.38 and 99.98–105.59%, respectively. LOD and LOQ were 0.088 and 0.294 μg mL⁻¹ for CDB and 0.121 and 0.403 μg mL⁻¹ for CDZ, respectively. The proposed method was successfully applied to the determination of CDB and CDZ in combined dosage forms and the results tallied well with the label claim.

Detection of A2142C, A2142G, and A2143G Mutations in 23s rRNA Gene Conferring Resistance to Clarithromycin among Helicobacter pylori Isolates in Kerman, Iran

BACKGROUND

Clarithromycin resistance in Helicbacter pylori has been found to be associated with point mutations in 23s rRNA gene leads to reduced affinity of the antibiotic to its ribosomal target or changing the site of methylation. The aim of this study was to determine the most important point mutations in 23s rRNA gene in H. pylori that are closely related to clarithromycin resistance among such isolates.

METHODS

Sixty three H. pylori isolates, obtained from gastric biopsy speciemens in Kerman, Iran, were used to evaluate their susceptibility to clarithromycin by disk diffusion test, and to detect the most common point mutations in 23s rRNA gene associated with clarithromycin resistance by Polymerase chain reaction-amplification and restriction fragment length polymorphism (PCR-RFLP) and 3'-mismatch PCR.

RESULTS

31.7% of the H. pylori isolates were resistant to clarithromycin, and each of the resistant isolate had at least one of the most common point mutations in 23s rRNA gene associated with calrithromycin resistance.

CONCLUSION

According to our results three common point mutation in 23s rRNA gene in H. pylori are closely related to clarithromycin resistance. There was an absolute relation between 23s rRNA gene point mutations and clarithromycin resistance in this study. Helicbacter pylori resistance to clarithromycin can cause failure in the eradications of the bacteria. The resistance of the bacteria is expanding in most parts of the world including Iran.

Simultaneous RP-HPLC Estimation of Trifluoperazine Hydrochloride and Chlordiazepoxide in Tablet Dosage Forms

A binary mixture of trifluoperazine HCl and chlordiazepoxide was determined using reversed-phase liquid chromatography method using methanol:water (97:03, v/v) pumped at a flow rate of 1.0 ml/min. Quantification was achieved with ultraviolet detection at 262 nm over concentration ranges of 0.1-1 and 0.5-5 mug/ml; mean accuracies were 101.05+/-0.47 and 98.97+/-0.33 %, respectively. The method was successively applied to tablet dosage forms as no chromatographic interferences from the tablet excipients were observed. The method retained its accuracy and precision when the standard addition technique was applied.

Voltammetric behavior and quantification of the sedative-hypnotic drug chlordiazepoxide in bulk form, pharmaceutical formulation and human serum at a mercury electrode

Chlordiazepoxide is a sedative-hypnotic drug widely employed as a transquilizer and anti-depressant. Its electrochemical behavior in Britton-Robinson (B-R) buffers of pH 2-11 at a mercury electrode has been investigated using dc-polarography, cyclic voltammetry and controlled-potential coulometry. Polarograms of the drug in B-R buffers of pH 2-10 exhibited three 2-electron waves, while at pH>10, only a single 4-electron wave was observed. The first, second, and third waves in buffers of pH<or=10 may be attributed to the reduction of N-oxide, C=N and C=N centers, respectively. The single wave (pH>10) may be due to the reduction of both the N-oxide and C=N centers in a one step. The shift of the E(1/2,) values to more negative potentials upon the increase of pH indicated the involvement of protons in the electrode reaction and that the proton-transfer reaction precedes the electrode process proper. The estimated data indicated that, one proton and two electrons are participated in the rate-determining step of each of the reduced centers. The general sequence of chlordiazepoxide reduction processes via each of its reactant centers may be expressed as: H(+), e, e, H(+)((fast)).Based on the interfacial adsorptive character of the drug onto the mercury electrode, a validated direct square-wave adsorptive cathodic stripping (SWAdCS) voltammetric procedure has been described for the trace determination of the drug in bulk form, tablets and human serum. The procedure did not require sample pretreatment or time-consuming extraction or evaporation steps prior to the assay of the drug. The optimized operational conditions of the proposed procedure have been found to be: accumulation potential E(acc.)=-0.9 V, accumulation time t(acc.)=30s, pulse-amplitude=50 mV, scan increment=10 mV and frequency=120 Hz. The proposed procedure is much more simple, fast, sensitive, costly low and achieved much more lower limits of detection (LOD) (4.4 x 10(-10)M and 6.6 x 10(-10)M) and limits of quantitation (LOQ) (1.5 x 10(-9)M and 2.2 x 10(-9)M), respectively in pharmaceutical formulation and spiked human serum, compared to previously reported methods.