Simultaneous Determination Of Hydrocortisone Research Articles

Simultaneous Determination of Hydrocortisone and Zn-Bacitracin by Spectrophotometric Derivative and Multivariate Methods

Four spectrophotometric methods are described and applied to resolve binary mixtures of the corticosteroid hydrocortisone and the antibacterial polypeptide Zn-Bacitracin. The simultaneous determination of the two compounds was accomplished by means of derivative methods, which were satisfactory used to determine synthetic mixtures of these compounds in different ratios and in pharmaceutical preparations (only for hydrocortisone). Direct absorption spectra of compounds were used to optimise the spectral data set performs the calibration by PLS-1, PLS-2 and PCR algorithms. These calibration models were evaluated through internal validation (prediction of compounds in its own designed training set of calibration), cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model) and external validation over synthetic and pharmaceutical mixtures. The four described procedures do not require any separation step. Precision studies were achieved over two series of ten standards for each compound showing no significant differences at 95% confidence level in the two spectrophotometric methods. The results found in commercial products were compared with those obtained by means of MEKC method and similar values were found.

Simultaneous determination of hydrocortisone, oxytetracycline and nystatin by liquid chromatography

A reverse phase high performance liquid chromatographic (HPLC) method to determine Hydrocortisone (HYD), Oxytetracycline (OXY) and Nystain (NYS) has been developed. The separation was made on a LichrCARTŖ C18 column using methanol-NaH2PO4/Na2HPO4 gradient elution and a diode-array detector measuring at the maximum absorption wavelength for each compound. Quantification limits ranging from 0.19 to 0.85 μg L−1 were obtained. The method was applied to synthetic mixtures and pharmaceutical formations. Analyses were made from the stock solutions and by means of standard addition. Both methods showed similar results, and the claimed levels of pharmaceutical preparations were sown to be in agreement with the results from our analytical method.

Simultaneous determination of hydrocortisone, dexamethasone, indomethacin, phenylbutazone and oxyphenbutazone in equine serum by high-performance liquid chromatography

Ethyl acetate extracts of equine serum, containing 0–5 μg/ml of hydrocortisone (HYD), dexamethasone (DEX), oxyphenbutazone (OPB), indomethacin (IND), phenylbutazone (PB) and probenecid as internal standard, were evaporated with nitrogen, resuspended in methanol and analyzed by HPLC, using a C-18 column equilibrated with 51:49 acetonitrile–water, 0.1% trifluoroacetic acid, at 1 ml/min. The eluate was monitored at 254 nm. The selectivity (inter-assay C.V.<4%), sensitivity (limits of quantitation of 0.25 μg/ml for HYD, DEX and IND, 0.5 μg/ml for PB and 1 μg/ml for OPB, despite the occurrence of significant degradation of OPB and PB during the analysis) and precision (intra-assay and inter-assay C.V.’s of about 3–6 and 9–15%, respectively) of the method appeared appropriate for anti-doping control of racehorses.

Simultaneous Determination of Hydrocortisone and Benzyl Alcohol in Pharmaceutical Formulations by Reversed-Phase High-Pressure Liquid Chromatography

An accurate, reproducible, and specific reversed-phase high-pressure liquid chromatographic (HPLC) procedure that simultaneously determines hydrocortisone and benzyl alcohol in a variety of pharmaceutical formulations is presented. Cream, gel, ointment, and solution formulations containing varying hydrocortisone and benzyl alcohol concentrations can be analyzed with only minor modifications in sample preparation. To provide optimum accuracy and reproducibility, phenethyl alcohol is used as an internal standard. The specificity of the procedure allows for the quantitative determination of hydrocortisone and benzyl alcohol in the presence of their degradation products and without interference from the phenethyl alcohol. The determinations can be performed with an analysis time of 10–13 min/sample.