A method for amending loose smokeless tobacco with menthol for administration in clinical studies.

INTRODUCTION: Menthol has long been incorporated as a flavor additive in tobacco products and can impact use behaviors. Despite its inclusion in some of the most popular flavored smokeless tobacco (ST) products (e.g., "mint" flavored products), few studies have systematically investigated the impact of menthol on ST use behaviors in prospective empirical studies. Rigorous investigation of ST menthol content on behavioral and physiological outcomes requires ST products with stable and precise levels of menthol; however, commercial product composition variability prevents product comparisons when evaluating the effects of systematic changes in menthol content on clinical outcomes. METHODS: We developed amended loose moist snuff ST products by treating commercially available, unflavored loose ST with an ethanol-based menthol spiking solution or a nonmentholated ethanol control solution to develop test products with different levels of menthol: 0, 1, 3, and 5 mg menthol/g tobacco. We evaluated the stability of menthol content in these products over 24 months and evaluated menthol exposure associated with the products through pharmacokinetic analysis of plasma menthol-glucuronide in human participants (n=22). RESULTS: Menthol content of the amended products was on target, homogenous, and stable for up to 24 months. Menthol exposure (menthol-glucuronide Cmax and AUC) significantly differed between each test product. CONCLUSIONS: These data suggest that stable products with nonoverlapping menthol content can be developed using a menthol spiking solution and can be subsequently administered for clinical assessments of mentholated loose ST. IMPLICATIONS: The results from this study suggest that a menthol spiking solution can be used to mentholate unflavored, loose ST to a target menthol content. With this method, the ST menthol content was stable for at least 24 months, and the products exposed users to menthol in a dose-dependent manner. This method yielded loose ST products with precise, stable levels of menthol to allow systematic evaluation of ST menthol content on clinical outcomes. The method may have applications for systematically evaluating changes in other tobacco product ingredients.

HS-GC-FID method for quantification of HFA-152a in cell culture media, and plasma from a range of species and regulatory compliant validations.

INTRODUCTION: 1,1-Difluoroethane (HFA-152a) is being developed as an alternative propellant in pressurized metered dose inhalers (pMDIs). As a part of the regulatory development pathway, pharmacology, toxicology and clinical studies have been conducted with inhaled HFA-152a. These studies require fit for purpose regulatory compliant (GxP validated) methods for quantification of HFA-152a from blood. METHODS: As HFA-152a is a gas at standard temperature and pressure, novel methods were developed to support the analysis across the wide range of species and concentrations required for regulatory filing. RESULTS: The developed methods utilized a headspace auto sampler coupled to a gas chromatograph (GC) with flame ionization detection. Key factors in the successful method included bringing together fit for purpose approaches to the head space vials, volume of matrix (blood), detection range required for species/study objective, handling / transfer of blood into head space vials and the stability/storage required for the analysis of the samples. The species-specific assays were fully validated under regulatory (GLP) conditions for mouse, rat, rabbit, canine and human and non-regulatory (non GLP) validations for guinea pig and cell culture media. DISCUSSION: Overall the novel approach of head space analysis of whole blood allowed for the development and validation of assays used to generate the toxicokinetic data that supported clinical testing of HFA-152a as a new pMDI propellant.

A one-step, solvothermal reduction method for producing reduced graphene oxide dispersions in organic solvents.

Refluxing graphene oxide (GO) in N-methyl-2-pyrrolidinone (NMP) results in deoxygenation and reduction to yield a stable colloidal dispersion. The solvothermal reduction is accompanied by a color change from light brown to black. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images of the product confirm the presence of single sheets of the solvothermally reduced graphene oxide (SRGO). X-ray photoelectron spectroscopy (XPS) of SRGO indicates a significant increase in intensity of the C=C bond character, while the oxygen content decreases markedly after the reduction is complete. X-ray diffraction analysis of SRGO shows a single broad peak at 26.24 degrees 2theta (3.4 A), confirming the presence of graphitic stacking of reduced sheets. SRGO sheets are redispersible in a variety of organic solvents, which may hold promise as an acceptor material for bulk heterojunction photovoltaic cells, or electromagnetic interference shielding applications.