HPLC determination of rubber septum contaminants in the iodinated intravenous contrast agent (sodium iothalamate)

Chromatographic and Spectral Analysis of Two Main Extractable Compounds Present in Aqueous Extracts of Laminated Aluminum Foil Used for Protecting LDPE-Filled Drug Vials

Laminated aluminum foils are increasingly being used to protect drug products packaged in semipermeable containers (e.g., low-density polyethylene (LDPE)) from degradation and/or evaporation. The direct contact of such materials with primary packaging containers may potentially lead to adulteration of the drug product by extractable or leachable compounds present in the closure system. In this paper, we described a simple and reliable HPLC method for analysis of an aqueous extract of laminated aluminum foil overwrap used for packaging LDPE vials filled with aqueous pharmaceutical formulations. By means of combined HPLC-UV, GC/MS, LC/MS/MS, and NMR spectroscopy, the two major compounds detected in the aqueous extracts of the representative commercial overwraps were identified as cyclic oligomers with molecular weights of 452 and 472 and are possibly formed from poly-condensation of the adhesive components, namely, isophthalic acid, adipic acid, and diethylene glycol. Lower molecular weight compounds that might be associated with the "building blocks" of these compounds were not detected in the aqueous extracts.

Development and validation of HPLC methods for the determination of potential extractables from elastomeric stoppers in the presence of a complex surfactant vehicle used in the preparation of parenteral drug products

HPLC methods were developed and validated for potential extractables [zinc dithiocarbamate, 2,6-di-tert-butyl-para-cresol (BHT), octylated diphenylamine antioxidant, sulfur, pentylphenol, and tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydro cinnamate))methane] from commercial elastomeric stoppers in a complex surfactant matrix. These stoppers were proposed to be part of the container-closure system for experimental formulations containing the surfactant, polyoxyethylated Castor oil (USP/NF) (POE Castor oil) and ethanol. The presence of POE Castor oil in the formulation posed unique challenges to the development and validation of the HPLC methods. POE Castor oil, also known as Cremophor, is a viscous and complex solubilizing agent with a number of uncharacterized fractions. Hence the goal was to identify HPLC conditions that would be suitable for the separation, detection, and quantitation of the potential stopper extractables in the presence of such a complex drug product matrix. A number of experiments were performed to evaluate the effects of different columns, mobile phase composition, injection volume, and gradient profile on the separation and detection of the potential stopper extractables. The quantitation limits of these stopper extractables are between 1 and 10 ppm. The methods demonstrate good linearity, acceptable accuracy, and precision.

Structural identification of extractables from rubber closures used for pre-filled semisolid drug applicator by chromatography, mass spectrometry, and organic synthesis

Extractables or leachables from rubber closures used for drug products can potentially be detrimental since some of these rubber extractables are known to be toxic and pyrogenic. In addition, these extractables could interfere with analysis or even affect the stability profile of the active ingredients. For these reasons, it became necessary to identify structures of the possible extractables or leachables from rubber closures so that their potential impact on the drug products that are in direct contact with rubber closures could be evaluated. In this report, five species, 4-(1,1-dimethyl-propyl)-phenol (1), sulfur (2), 2,6-di-tert-butyl-[1,4] benzoquinone (3), furan-2-yl-(5-hydroxymethyl-furan-2-yl)-methanol (4), and 2-bromo-4-(1,1-dimethyl-propyl)-phenol (5), were found to be possible extractables from the rubber closures which were used in a selected pre-filled semisolid drug applicator. A strategy combining HPLC, GC, mass spectrometry, and organic synthesis was utilized.