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A precise and reliable reversed-phase high-performance liquid chromatographic method with ultraviolet detection was developed and validated to determine cinitapride in human plasma. After liquid-liquid extraction, chromatographic separation was achieved on a Nucleosil C18 (25 cm × 4.6 mm, 5 µm) column with an isocratic elution consisting of 10 mM ammonium acetate (pH 5.2), methanol, and acetonitrile, 40 : 50 : 10, v/v/v. The developed method was validated as per US FDA guidelines for its linearity, selectivity, sensitivity, precision, accuracy, and stability. Satisfactory findings were obtained from the validation studies. The linearity range of the method was 1 to 35 ng/mL while the extraction recovery of cinitapride in human plasma was more than 86%. The percent coefficient of variation of both intraday and interday precision was ≤7.1%.

A reversed phase liquid chromatographic method with UV detection at 254 nm for dorzolamide assay in ophthalmic solutions was developed and validated. Chromatographic separation was achieved on a Zorbax SB C18 (250 mm × 4.6 mm, 5 µm) column kept at 30°C with an isocratic mixture of mobile phase (phosphate buffer, pH 2.5, and acetonitrile, 90 : 10 v/v) at a flow rate of 0.8 mL/min. The method was validated for its specificity, linearity, accuracy, precision, limit of detection, limit of quantification, and robustness based on ICH guidelines. The validation studies revealed satisfactory results. The proposed method has been applied for the quantification of dorzolamide in commercial samples. The developed method is fast, simple, specific, accurate, and sensitive, hence can be applied for routine quality control analysis of dorzolamide in pharmaceutical dosage form.

A simple extractive spectrophotometric technique has been developed and validated for the determination of miconazole nitrate in pure and pharmaceutical formulations. The method is based on the formation of a chloroform-soluble ion-pair complex between the drug and bromocresol green (BCG) dye in an acidic medium. The complex showed absorption maxima at 422 nm, and the system obeys Beer’s law in the concentration range of 1–30 µg/mL with molar absorptivity of 2.285 × 104 L/mol/cm. The composition of the complex was studied by Job’s method of continuous variation, and the results revealed that the mole ratio of drug : BCG is 1 : 1. Full factorial design was used to optimize the effect of variable factors, and the method was validated based on the ICH guidelines. The method was applied for the determination of miconazole nitrate in real samples.

Two chemometrics methods—principal component regression and partial least squares—were developed for simultaneous spectrophotometric estimation of ciprofloxacin and doxycycline hyclate in pharmaceutical dosage forms without any pretreatment. The UV spectra of both drugs were recorded at concentrations within their linear ranges between 200 and 400 nm with the intervals λ = 2 nm at 100 wavelengths in distilled water. Beer’s law was obeyed for both drugs in the concentration ranges of 1–10 μg/mL for ciprofloxacin and 5–25 μg/mL for doxycycline hyclate. Two sets of standard mixtures, 25 as a calibration set and 9 as a validation set, were prepared. The calibration models were evaluated by cross-validation and external validation over synthetic mixtures. The optimized models were successfully applied for chemometric analysis of ciprofloxacin and doxycycline hyclate in synthetic and pharmaceutical mixtures with satisfactory accuracy (recovery values from 97.50% to 101.87%) and precision (RSD < 2%).

This study aimed at determination of heavy metals (cadmium, lead, and zinc) in milk-based infant formulas collected from Mekelle, Ethiopia, and their associated health risks to the infants through consumption of these products. The infant feeding samples were dry-ashed in a muffle furnace followed by digestion in nitric acid and the resulting solutions were analyzed by flame atomic absorption spectrophotometer. Cadmium was not detected in the samples while the levels of lead and zinc ranged from not detected value to 0.103 mg/kg and from 27.888 to 71.553 mg/kg, respectively. The estimated daily intake values and the health risk indices of both metals were below their respective safety limits and the threshold of 1, respectively. These findings show low infant health risk of these metals through consumption of these products. Nevertheless, regular monitoring of infant formula for toxic metals is required since infants are potentially more susceptible to metals.