The Development of Spectrophotometric and Validated Stability- Indicating RP-HPLC Methods for Simultaneous Determination of Ephedrine HCL, Naphazoline HCL, Antazoline HCL, and Chlorobutanol in Pharmaceutical Pomade Form

Evaluation of stability of (1R,2 S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride in plasma and urine samples-inoculated with Escherichia coli using high-performance liquid chromatography (HPLC)

The preservation of drug stability in biological evidence during the processes of collection and storage poses a substantial obstacle to the progress of forensic investigations. In conjunction with other constituents, the microorganisms present in the samples play a vital role in this investigation. The present investigation employed the high-performance liquid chromatography (HPLC) technique to assess the stability of (1R,2 S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride in plasma and urine samples that were inoculated with Escherichia coli. These samples were subjected to storage conditions of 37 °C for 48 h and - 20 °C for a duration of 6 months. Minimal inhibitory concentration (MIC) and Minimal bactericidal concentration (MBC) of MPPH against E. coli were determined using microdilution method. The stability of MPPH in plasma and urine samples inoculated with E. coli was investigated using HPLC method. The results showed the MIC and MBC of MPPH were 87.5 ± 25 ppm and 175 ± 50 ppm, respectively. While MPPH remained stable in plasma for 48 h at 37 °C, it showed a notable decrease of about 11% in stability when stored in urine for the same period and temperature. From the beginning of the first month, a decrease in the stability of the compound appeared in all samples that were stored at - 20 °C, and the decrease reached 7% for plasma samples and about 11% for urine samples. The decrease in the stability reached its peak in the sixth month, reaching more than 30% and 70% of plasma and urine samples preserved at - 20 °C. This work concluded that E. coli can negatively affect the stability of MPPH in plasma and urine samples. This may lead to incorrect conclusions regarding the analysis of biological samples in criminal cases.

Green Easily Implemented Spectrophotometric Methods for Concurrent Determination of Ephedrine Hydrochloride and Naphazoline Nitrate in Nasal Preparations Containing Methylparaben

BACKGROUND

Spectrophotometric resolution of a mixture of several drugs is considered a cheaper, simpler, and more versatile alternative compared to costly chromatographic instruments.

OBJECTIVE

The work aims to resolve the interfering spectra of ephedrine hydrochloride, naphazoline nitrate, and methylparaben in nasal preparations using smart spectrophotometric methods.

METHOD

In our work, derivative and dual-wavelength methods were combined to eliminate this interference, under the name of derivative dual-wavelength method. Other methods, namely successive derivative subtraction and chemometric analysis, were also able to eliminate this interference. The methods have proven their applicability as they follow the International Conference on Harmonization (ICH) requirements regarding repeatability, precision, accuracy, selectivity, and linearity. Eco-scale, GAPI, and AGREE tools were used to estimate the possible environmental effects of the methods.

RESULTS

Acceptable results for repeatability, precision, accuracy, selectivity, and linearity were obtained. Limit of detection (LOD) values were 2.2 for ephedrine and 0.3 for naphazoline. The correlation coefficients were above 0.999. The methods were proven to be safe for application.

CONCLUSIONS

The introduced methods are cheap and easily implemented compared to chromatographic techniques. They can be used in purity-checking of raw material and estimation of concentrations in market formulations. The replacement of the published chromatographic techniques with our developed methods is useful when needing to save money, effort, and time.

HIGHLIGHTS

The three components of a decongestant nasal preparation were determined using cheap, green, and versatile spectrophotometric methods that keep the advantages of chromatographic techniques, including accuracy, reproducibility, and selectivity.

Stability of (1R,2S)-(-)-Ephedrine hydrochloride in Candida albicans-inoculated urine and blood samples

The stability of drugs in biological evidence during collection and storage is of particular concern in forensic investigations. Microbes in the samples and other elements are an essential component of these investigations. In the current study, the HPLC method was used to examine the stability of (1R, 2S)-(-)-Ephedrine hydrochloride in plasma and urine samples inoculated with C. albicans after storage at 37 °C for 48 h and -20 °C for six months. In the stability experiment, MIC_50% of (1R, 2S)-(-)-Ephedrine hydrochloride was applied according to MIC and MFC that were determined in this work. This drug had MIC and MFC of 50 and 100 ppm, respectively. In HPLC analysis, the standard (1R, 2S)-(-)-Ephedrine hydrochloride had a retention time of 1.63 and was used to identify this drug in samples that had or had not been exposed to C. albicans. The findings demonstrated that within 48 h at 37 °C, C. albicans had an impact on the drug concentration (10% and more than 15%, respectively, were lost in plasma and urine samples inoculated with C. albicans). In plasma samples, the drug content remained stable at -20 °C for three months, although it degraded in urine samples after one month. In plasma and urine samples, the concentration reduction had surpassed 70% and 50% by the sixth month, respectively. The results of this investigation show that C. albicans can change the stability of (1R, 2S)-(-)-Ephedrine hydrochloride in plasma and urine samples that contain MIC_50% of Ephedrine hydrochloride.

Development and Validation of a Novel HPLC Method for the Determination of Ephedrine Hydrochloride in Nasal Ointment

A simple, precise, and cost-effective reverse phase ion pair chromatographic (RP-IP-HPLC) method was developed and validated for the determination of Ephedrine Hydrochloride in a nasal ointment. A simple and fast extraction protocol was developed for the effective recovery of the analyte, and for this purpose, Bromhexine Hydrochloride was used as the internal standard. The mobile phase consisted of MeOH, Sodium Lauryl Sulfate (SLS) 49.8 mM, triethylamine (ET3N) in the ratio of 65:34.6:0.4%, respectively, with pH = 2.20. The detection of the compounds was carried out at 206 nm, and we used a PDA detector. A short run time was achieved with retention times of 6.3 min and 9.8 min for ephedrine hydrochloride and the internal standard, respectively. The proposed method was validated according to ICH guidelines. Linearity was confirmed in the range of 50–150 μg/mL. Recoveries results were within the range of 98–102% and precision < 2% for the analyte in spiked blank matrix. Robustness testing was conducted via a fractional factorial experimental design. The method was found to fulfill the required specifications for specificity and stability for both standard solutions and samples, as well and applied to the determination of ephedrine hydrochloride in nasal ointments produced by the Greek Military Pharmaceutical Laboratories.