Coupling of Physical and Chromatographic Separation for Analyzing Cream Containing Miconazole, Mometasone Furoate and Gentamicin Sulphate

High-performance liquid chromatographic method was developed, validated and applied for miconazole, mometasone and gentamicin in Momenta® cream. Physical separation was applied using two extraction procedures due to different solubility of the three components. First, a methanolic extract of the cream contained miconazole and mometasone was chromatographed on ODS-3 Inertsil C18 column (150 × 4.6, 5 μm) using acetonitrile: water (80:20, v/v) as a mobile phase, flow rate 1.5 mL·min-1, scanned at 230 nm, showing tR 2.817 and 6.808 min for mometasone and miconazole, respectively. Second, an aqueous extract of the cream containing gentamicin was derivatized with o-phthalaldehyde in order to enhance the gentamicin UV detection and subjected to ion pairing chromatography on Inertsil ODS-3 C18 column (150 × 4.6, 5 μm), using methanol: 0.025 M heptane sulphonic acid: glacial acetic acid (75:20:5, by volume) as a mobile phase, flow rate 0.8 mL·min-1, scanned at 330 nm where the three active gentamicin isomers were separated at tR 11.7, 15.6 and 18.3 min. Suitability of this method for quantitative estimation of the drugs was proved by validation according to ICH guidelines. The method was selective, precise and accurate so could be used for analysis of cream formulation in QC labs.

RP-HPLC-UV Detection Method for the Simultaneous Determinat ion of Econazole Nitrate, Triamcinolone Acetonide and Benzoic Acid in Ternary Mixture

Background:

Econazole nitrate and triamcinolone acetonide are one of the topical antifungal corticosteroid fixed combinations. Although this combination has been literately investigated, yet their ternary mixture with benzoic acid as preservative lack of a simple method for its determination.

Objective:

The objective of this work is to present simple, accurate, precise and low cost reversed-phase liquid chromatography (RP-LC) method for the separation and determination of econazole nitrate, triamcinolone acetonide and benzoic acid in a ternary mixture.

Methods:

Separation was conducted on Mediterranea C18 (150mm x 4.6mm, 5μm) column using methanol: 50 mM potassium dihydrogen phosphate buffer (pH 2.60±1), (70:30, v/v) as a mobile phase at ambient temperature. Isocratic flow rate at 1 ml/min was used and UV detection was carried out at 230 nm. The Linearity, accuracy and precision of the developed method investigated as per ICH guidelines.

Results:

Good separation of two drugs, benzoic acid as preservative and excipients of dosage form was achieved with acceptable retention times (< 8 min). Validation parameters tested including linearity, accuracy and precision were found to be satisfactory over the concentration range (10-200 µg/ml) for econazole nitrate, (1-20 µg/ml) for triamcinolone acetonide and (2-40 μg/ml) for benzoic acid.

Conclusion:

The proposed method showed good separation and demonstrated adequate specificity, robustness and accuracy for the quantification of the tested drugs in laboratory prepared mixtures and in pharmaceutical preparations.

Evaluation of graphical and statistical representation of analytical signals of spectrophotometric methods

Simultaneous determination of miconazole (MIC), mometasone furaoate (MF), and gentamicin (GEN) in their pharmaceutical combination. Gentamicin determination is based on derivatization with of o-phthalaldehyde reagent (OPA) without any interference of other cited drugs, while the spectra of MIC and MF are resolved using both successive and progressive resolution techniques. The first derivative spectrum of MF is measured using constant multiplication or spectrum subtraction, while its recovered zero order spectrum is obtained using derivative transformation. Beside the application of constant value method. Zero order spectrum of MIC is obtained by derivative transformation after getting its first derivative spectrum by derivative subtraction method. The novel method namely, differential amplitude modulation is used to get the concentration of MF and MIC, while the novel graphical method namely, concentration value is used to get the concentration of MIC, MF, and GEN. Accuracy and precision testing of the developed methods show good results. Specificity of the methods is ensured and is successfully applied for the analysis of pharmaceutical formulation of the three drugs in combination. ICH guidelines are used for validation of the proposed methods. Statistical data are calculated, and the results are satisfactory revealing no significant difference regarding accuracy and precision.