A Full Evaporation Static Headspace Gas Chromatography Method with Nitrogen Phosphorous Detection for Ultrasensitive Analysis of Semi-volatile Nitrosamines in Pharmaceutical Products

The recent detection of potent carcinogenic nitrosamine impurities in several human medicines has triggered product recalls and interrupted the supply of critical medications for hundreds of millions of patients, illuminating the need for increased testing of nitrosamines in pharmaceutical products. However, the development of analytical methods for nitrosamine detection is challenging due to high sensitivity requirements, complex matrices, and the large number and variety of samples requiring testing. Herein, we report an analytical method for the analysis of a common nitrosamine, N-nitrosodimethylamine (NDMA), in pharmaceutical products using full evaporation static headspace gas chromatography with nitrogen phosphorous detection (FE-SHSGC-NPD). This method is sensitive, specific, accurate, and precise and has the potential to serve as a universal method for testing all semi-volatile nitrosamines across different drug products. Through elimination of the detrimental headspace-liquid partition, a quantitation limit of 0.25 ppb is achieved for NDMA, a significant improvement upon traditional LC-MS methods. The extraction of nitrosamines directly from solid sample not only simplifies the sample preparation procedure but also enables the method to be used for different products as is or with minor modifications, as demonstrated by the analysis of NDMA in 10+ pharmaceutical products. The in situ nitrosation that is commonly observed in GC methods for nitrosamine analysis was completely inhibited by the addition of a small volume solvent containing pyrogallol, phosphoric acid, and isopropanol. Employing simple procedures and low-cost instrumentation, this method can be implemented in any analytical laboratory for routine nitrosamine analysis, ensuring patient safety and uninterrupted supply of critical medications.

Physicochemical Stability of a Novel Tacrolimus Ophthalmic Formulation for the Treatment of Ophthalmic Inflammatory Diseases

Tacrolimus is an immunosuppressant used to treat a large variety of inflammatory or immunity-mediated ophthalmic diseases. However, there are currently no commercial industrial forms available that can provide relief to patients. Various ophthalmic formulations have been reported in the literature, but their stability has only been tested over short periods. The objective of this study was to evaluate the physicochemical stability of a preservative-free tacrolimus formulation (0.2 and 1 mg/mL) at three storage temperatures (5 °C, 25 °C and 35 °C) for up to nine months in a multidose eyedropper. Analyses performed were the following: visual inspection and chromaticity, turbidity, viscosity, size of micelles, osmolality and pH measurements, tacrolimus quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. In an in-use study, tacrolimus quantification was also performed on the drops emitted from the eyedroppers. All tested parameters remained stable during the nine month period when the eyedrops were stored at 5 °C. However, during storage at 25 °C and 35 °C, several signs of chemical instability were detected. Furthermore, a leachable compound originating from a silicone part of the eyedropper was detected during the in-use assay. Overall, the 0.2 mg/mL and 1 mg/mL tacrolimus ophthalmic solutions were physicochemically stable for up to nine months when stored at 5 °C.

A fast, single column extraction chromatography method for the isolation of Neodymium from iron-rich materials prior to radiogenic isotope ratio measurements

A novel separation method is described for the separation of Nd from Fe-rich, silicate samples in view of isotopic analyses. The procedure is based on the synergistic enhancement of the...

A Simple Route for the Preparation of Gold Nanofilms and Their Application in SERS Detection of Pyrene in Water

Design and preparation of various rational gold nanostructures has been recognized as a promising solution for the surface-enhanced Raman scattering (SERS) signal amplification. Here, a simple fabrication method was reported for the synthesis of highly sensitive gold nanofilms for SERS detection through covering ginger-liked gold nanoparticles on the stainless steel sheet. The prepared gold nanofilms were then tested by a dip-SPME-SERS method for detecting pyrene. The limit of detection for pyrene standard solution was 0.1ppb, while the limit of detection for pyrene in tap water and lake water without any pretreatment was 5 ppb, respectively. The whole analysis process takes less than 15 minutes. Our method may be a potential alternative way to the chromatography method. The fabricated gold nanfilms are expected to be used for the rapid and sensitive detection of other pollutants such as organic pesticides and polycyclic aromatic hydrocarbon.

Stability of 1-unit/mL insulin aspart solution in cyclic olefin copolymer vials and polypropylene syringes

Disclaimer In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose This study evaluated the stability of diluted insulin aspart solutions (containing insulin aspart and preservatives) at their most commonly used concentration in intensive care units (1 unit/mL), in 2 container types: cyclic olefin copolymer (COC) vials and polypropylene (PP) syringes. Methods Insulin aspart solution (1 unit/mL, diluted in 0.9% sodium chloride injection) was stored for 365 days in COC vials with gray stoppers and PP syringes at refrigerated (5±3°C) and ambient temperatures (25°C ± 2°C at 60% ± 5% relative humidity and protected from light). Chemical testing was conducted monthly using a validated high-performance liquid chromatography method (quantification of insulin aspart, phenol, and metacresol). Physical stability was evaluated monthly via pH measurements, visible and subvisible particle counts, and osmolality measurements. Sterility testing was also performed to validate the sterile preparation process and the maintenance of sterility throughout the study. Results The limit of stability was set at 90% of the initial concentrations of insulin aspart, phenol, and metacresol. The physicochemical stability of 1-unit/mL insulin solutions stored refrigerated and protected from light, was unchanged in COC vials for the 365-day period and for 1 month in PP syringes. At ambient temperature, subvisible particulate contamination as well as the chemical stability of insulin and metacresol were acceptable for only 1 month’s storage in PP syringes, while insulin chemical stability was maintained for only 3 months’ storage in COC vials. Conclusion According to our results, it is not recommended to administer 1-unit/mL pharmacy-diluted insulin solutions after 3 months’ storage in COC vials at ambient temperature or after 1 month in PP syringes at ambient temperature. The findings support storage of 1-unit/mL insulin aspart solution in COC vials at refrigerated temperature as the best option over the long term. Sterility was maintained in every condition. Both sterility and physicochemical stability are essential to authorize the administration of a parenteral insulin solution.

VALIDATION OF STABILITY INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS ESTIMATION OF TELMISARTAN AND HYDROCHLOROTHIAZIDE CONTENT IN BULK AND PHARMACEUTICAL DOSAGE FORM

A simple, accurate, precise and rapid stability indicating reverse phase High performance chromatography method was used for estimation of Telmisartan and Hydrochlorothiazide in bulk and fixed-dose combination solid oral dosage form. The proposed analytical method has been validated for specificity, Linearity, Accuracy, Precision and Robustness. The chromatography was achieved in a GL science, Inertsil C8 (Length 125x Diameter 4.0mm Particle size 5µm) column with gradient flow. The optimal chromatographic condition consisted of mobile phase pH 3.0 at a flow rate of 1.2mL/min, with a column temperature of 40°C, run time 14 minutes and detector wavelength of 270nm.

Development of a high-performance liquid chromatography method for simultaneously analyzing Guanosine 5’-monophosphate (GMP) and Inosine 5’-monophosphate (IMP) in food

This study aimed to develop a HPLC method to simultaneously analyze guanosine 5’-monophosphat (GMP) and inosine 5’-monophosphat (IMP) in food products. Sample preparation procedure was simple, fast. A C18 column (250 mm × 4.6 mm, 5 µm) was used as stationary phase, and a mixture of 10 mM potassium dihydrogen phosphate and 5 mM sodium heptanesulfonate was applied as mobile phase, and PDA detector at 250 nm. The method validation followed AOAC criteria. Selectivity, linearity (R2 > 0.999), recovery (IMP: 90.5 % - 102.8 %, GMP: 91.5 % - 103.9 %), repeatability (RSDR of IMP: 3.07 % and GMP: 2.83 %) were acceptable to determination GMP and IMP in food matrix under AOAC guidelines. LOD of GMP and IMP were of 2.32 and 2.77 mg/kg, respectively. This method was used to determination GMP, IMP in food products collected in Hanoi markets.