Development and Validation of a RP-HPLC Method for the Simultaneous Determination of Silver Sulfadiazine and Sodium Hyaluronate in the Presence of Methyl and Propyl Paraben in a Pharmaceutical Cream for Burns

A direct and precise isocratic RP-HPLC method for simultaneous determination of silver sulfadiazine (SSD) and sodium hyaluronate (SH) in the presence of methyl (MP) and propyl parabens (PP) was developed and validated. Agilent chromatograph with X-Select C18 column (250 × 4.6 mm2, 5 μm) was used. Chromatographic separation was achieved using a mobile phase consisting of acetonitrile and 0.05 M phosphate buffer (pH 5.0 to which added triethyl amine 0.5 ml/L), at a ratio 35: 65 v/v. Elution was used at flow rate of 1.0 mL/min at ambient temperature with UV detection at 205 nm. The retention times for SH, SSD, MP and PP were 1.49, 3.3, 6.7 and 19.5 min, respectively. The presented chromatographic method was fully validated in accordance with ICH requirements, it was valid over linearity ranges of (0.80-100.00 μg/mL) and (3.20-100.00 μg/mL) for SSD and SH, respectively. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges and the sensitivity of the method, as the limits of detection and quantification for each active ingredient was also determined. The validated method was successfully applied for the quantification of SSD and SH in pharmaceutical cream formulation and the mean recovery % ± SD were 100.93 ± 0.985 and 100.05 ± 0.668 for SSD and SH; respectively, indicating satisfactory accuracy of the method.

Chemometric design-based optimization of a green, selective and inexpensive switchable hydrophilicity solvent-based liquid phase microextraction procedure for pre-concentration and extraction of sulfadiazine in milk, honey and water samples

In this research, a green, selective and inexpensive switchable hydrophilicity solvent-based liquid phase microextraction (SHS-LPME) procedure has been optimized for the extraction and preconcentration of sulfadiazine (SDZ) in milk, honey and water samples prior to spectrophotometric analysis. Five variables affecting the SHS-LPME procedure were optimized using chemometric-based central composite design. For the SHS-LPME procedure, analytical parameters such as linearity, limit of detection, extraction recovery and enrichment factor were 15-300 μg L^-1, 4.5 μg L^-1, 96 ± 3% and 113, respectively. The precision of the method was investigated by repeatability and reproducibility studies. The relative standard deviation from these studies was found in the range of 2.4-4.5%. The recovery of the SDZ in the samples was in the range of 94 ± 4-99 ± 2%. Collected samples were analyzed by both the SHS-LPME procedure and the reference method using flow injection-flame atomic absorption technique, and the results were compared. There was no statistically significant difference between the two methods. This showed that the SHS-LPME procedure can be safely applied to the analysis of real samples.

Application of graphene oxide-silica composite reinforced hollow fibers as a novel device for pseudo-stir bar solid phase microextraction of sulfadiazine in different matrices prior to its spectrophotometric determination

This study presents a novel, simple and efficient pseudo-stir bar solid phase microextraction method for separation and preconcentration of sulfadiazine. To develop the method, a graphene oxide-silica composite reinforced hollow fiber was prepared via sol-gel technology and used as a novel device to extract sulfadiazine. The retained sulfadiazine was eluted using 180μL of methanol/acetic acid (6:4) and quantified by fiber optic linear array spectrophotometry based on the formation of its azo dye with thenoyltrifluoroacetone. Under optimized conditions, the method exhibited a linear dynamic range of 5-150μgL^-1 with a detection limit of 1.5μgL^-1 and an enrichment factor of 100. The relative standard deviations of 2.9% and 5.8% (n=6) were obtained at 60μgL^-1 level of sulfadiazine for intra- and inter-day analysis respectively. The method was successfully applied to determine sulfadiazine in honey, milk, human urine and environmental water samples.