Development and validation of an HPLC assay for fentanyl, alfentanil, and sufentanil in swab samples.

A high performance liquid chromatography (HPLC) method for the assay of fentanyl citrate, alfentanil hydrochloride, and sufentanil citrate swab samples was developed and validated in order to control a cleaning procedure. The swabbing procedure involved Super POLX 1200 wipers moistened with water. The assay employed extraction of swabs with water and analysis by isocratic, reversed-phase, HPLC with varying ultraviolet (UV) detection for desired sensitivity, depending on the analyte. The method was shown to be selective and linear from the limits of quantitation (0.10, 0.20, and 0.15 microg/swab for fentanyl citrate, alfentanil, and sufentanil, respectively) to over three times these concentrations. The assay limits (detection levels) per swab area were set at least at 0.2% of the concentrations of the actives in the drug products (0.02, 0.10, and 0.10 microg/swab or approximately 0.03, 0.02, and 0.2% for fentanyl citrate, alfentanil, and sufentanil, respectively). It should be noted that all active concentrations listed in this work were calculated based on the salt form concentration for fentanyl (citrate salt) and the free base forms for alfentanil and sufentanil. No reference standard was available for alfentanil hydrochloride and sufentanil citrate. Drug product was used instead throughout this study.

Development and validation of an HPLC assay for fentanyl and related substances in fentanyl citrate injection, USP.

The stability indicating properties of the USP method for the assay of fentanyl in fentanyl citrate injection were evaluated [1] by analyzing fentanyl drug substance and product after acid, hydrogen peroxide, heat, and light treatment. N-phenyl-N-(4-piperidinyl)propionamide (PPA), which is a known degradation product/process impurity of fentanyl, was not adequately resolved from the fentanyl peak, and mobile phase adjustments did not improve the resolution (Fig. 1). Therefore, the USP method did not meet the requirements for a stability-indicating assay. In addition, the wavelength in the USP method was too high (230 nm) to provide adequate levels for the quantitation of the related substances of fentanyl and, in addition, the acetate ions in the mobile phase could interfere with a lower wavelength detection. An isocratic, reversed phase, stability indicating, high performance liquid chromatographic (HPLC) method for the assay of fentanyl and related substances in fentanyl citrate injection, USP has been developed and validated. The chromatographic conditions employed an Inertsil C8, 5 column (25 cm x 4.6 mm), a mobile phase of aqueous perchloric acid [0.23%, w/v]-acetonitrile [65:35, v/v], and ultraviolet (UV) detection at 206 nm. Under the chromatographic conditions of the method, PPA and seven other known process impurities were separated from the active. Degradation studies showed that the active eluted as a spectrally pure peak resolved from its degradation products.

Method development and validation for the HPLC assay (potency and related substances) for 20 mg paroxetine tablets.

A reversed phase high performance liquid chromatographic (HPLC) method was developed and validated for use as a stability indicating assay (potency and related substances) of paroxetine in paroxetine hydrochloride 20 mg tablets. Assay samples were extracted at a paroxetine concentration of 0.4 mg ml(-1) utilizing mobile phase as the extraction solvent. The chromatographic conditions employed a C18 column (Inertsil, 5 microm, 15 cm x 4.6 mm), isocratic elution with 10 mM 1-decane sulfonic acid sodium salt containing 10 mM sodium phosphate monobasic (pH 3.0)-ACN (60:40, v/v) and ultraviolet (UV) detection at 235 nm.

High-performance liquid chromatography with light-scattering detection and desorption chemical-ionization tandem mass spectrometry of milk fat triacylglycerols.

The utility of reverse-phase high-performance liquid chromatography (HPLC), desorption chemical-ionization mass spectrometry (DCI-MS) and tandem mass spectrometry (MS/MS) for the characterization of triacylglycerols in complex mixtures has been further explored. Triacylglycerols of anhydrous bovine milk fat were separated by using two reverse-phase C18 HPLC columns, and eluents were monitored with an evaporative light-scattering detector. Fifty-eight fractions were resolved and analyzed by positive ion isobutane DCI-MS. The formation of protonated molecules and of major fragments corresponding to the random loss of any one of the constituent fatty acids readily identified acyl carbon numbers and the number of double bonds within each fatty acid. MS/MS was only required when the original mass spectra indicated the presence of more than one triacylglycerol or of impurities in a fraction. Protonated molecules produced by DCI were fragmented using high energy collisional activation, and the resulting ions were detected by MS/MS. Odd-chain triacylglycerols were also readily distinguished using this methodology. The positive ion DCI and MS/MS techniques described here demonstrate the usefulness of this approach for the characterization of triacylglycerols in complex mixtures.

Preoperative chemotherapy for giant cell carcinoma of the thyroid.

Reported is the case of a 24-year-old white man with inoperable giant cell carcinoma of the thyroid who achieved tumor regression following therapy with bleomycin, Adriamycin and cisplatinum. After 2 courses of chemotherapy, the tumor was deemed operable, and the patient underwent total thyroidectomy followed by radiation to the neck and upper mediastinum without maintenance chemotherapy. Two-and-one-half years after the initial diagnosis, he developed pulmonary metastases which again responded to Adriamycin and cisplatinum therapy. The above approach suggests that inoperable thyroid carcinoma can be made operable by preoperative combination chemotherapy. This treatment program deserves further exploration for a greater number of patients.