Evaluating the impact of the Adelaide Rural Clinical School longitudinal clinical placement on the rural medical workforce: A retrospective cohort study of graduates, 2004-2019.

Objective: To evaluate the contribution of the Adelaide Rural Clinical School (ARCS) longitudinal integrated clerkship to the rural medical workforce.

Methods: Design: Retrospective cohort study.

Setting: Practice location data were sourced from the Australian Health Practitioner Regulation Agency (AHPRA, January 2021) and matched using university records.

Enantiomeric purity analysis of synthetic peptide therapeutics by direct chiral high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

The determination of chiral purity is critical to the evaluation of the quality of peptide pharmaceutical products. For synthetic peptides, the undesirable d-isomers can be introduced as impurities in amino acid starting materials and can also be formed during peptide synthesis and in some cases during product shelf life. A chiral high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method is described that facilitates rapid and accurate determination of amino acid chiral purity of a peptide.

Evaluation of a hydrophilic interaction liquid chromatography design space for sugars and sugar alcohols.

Based on a column-screening exercise, a column ranking system was developed for sample mixtures containing any combination of 26 sugar and sugar alcohol analytes using 16 polar stationary phases in the HILIC mode with acetonitrile/water or acetone/water mobile phases. Each analyte was evaluated on the HILIC columns with gradient elution and the subsequent chromatography data was compiled into a statistical software package where any subset of the analytes can be selected and the columns are then ranked by the greatest separation. Since these analytes lack chromophores, aerosol-based detectors, including an evaporative light scattering detector (ELSD) and a charged aerosol detector (CAD) were employed for qualitative and quantitative detection.

Aerosol-based detectors for liquid chromatography.

Aerosol-based detectors developed within the last few decades have increasingly addressed the need for sensitive, universal liquid chromatography detection in a wide variety of applications. Herein, we review the operating principles, instrumentation, analytical characteristics, and recent applications of the three general types of such detectors: evaporative light scattering detection (ELSD), condensation nucleation light scattering detection (CNLSD); commercially known as the nano-quantity analyte detector (NQAD), and charged aerosol detection (CAD). Included is a comparative evaluation of the operational and analytical characteristics of these detectors.

Analysis of magnesium from magnesium stearate in pharmaceutical tablet formulations using hydrophilic interaction liquid chromatography with nano quantity analyte detection.

This study demonstrates the use of hydrophilic interaction liquid chromatography with a nano quantity analyte detector for the retention, separation and detection of magnesium from magnesium stearate in tablet formulations for a drug product formulation blend containing a hydrochloride salt of a weakly basic compound as the active ingredient. The nano quantity analyte detector can provide direct detection of inactive excipients and inorganic salts lacking ultraviolet chromophores, as well as, all non-volatile compounds. The separation was accomplished using a SeQuant ZIC-HILIC column and mobile phase consisting of 32.

Hydrophilic interaction chromatography with aerosol-based detectors (ELSD, CAD, NQAD) for polar compounds lacking a UV chromophore in an intravenous formulation.

In this work, a high performance liquid chromatography (HPLC) method is reported for the separation and quantitation of a drug substance that is highly polar and lacking a chromophore in a mannitol intravenous (IV) formulation. Three polar stationary phases operated in hydrophilic interaction chromatography (HILIC) mode were evaluated in conjunction with an Alltech 800 ELSD detector. These columns were evaluated with respect to chromatographic properties such as buffer, pH and organic concentrations to identify the best stationary phase.

Estimating the national public health burden associated with exposure to ambient PM2.5 and ozone.

Ground-level ozone (O(3)) and fine particulate matter (PM(2.5)) are associated with increased risk of mortality. We quantify the burden of modeled 2005 concentrations of O(3) and PM(2.

Weak bases and formation of a less soluble lauryl sulfate salt/complex in sodium lauryl sulfate (SLS) containing media.

This work reports on the solubility of two weakly basic model compounds in media containing sodium lauryl sulfate (SLS). Results clearly show that the presence of SLS in the media (e.g.

A simple and efficient approach to reversed-phase HPLC method screening.

The development and utility of an efficient HPLC method screening strategy using only four columns for the separation of pharmaceutical compounds and related impurities is presented. The strategy established a two-column approach to enable rapid early method development, along with a four-column approach for commercial method development of the analytical methods utilized to verify the quality of drug substance or drug product. Mobile phases consisted of acetonitrile or methanol with aqueous trifluoroacetic acid for low pH screening, and ammonium hydroxide for high pH screening.

Empirical observations and mechanistic insights on the first boron-containing chiral selector for LC and supercritical fluid chromatography.

Boromycin is a macrodiolide that exists as a hydrophobic Böeseken complex formed from boric acid and a chiral polyhydroxy macrocyclic ligand. It was covalently bonded to silica gel through a urea linkage to an attached d-valine ester. When evaluated as a chiral stationary phase, it shows pronounced enantioselectivity toward primary amine-containing racemates, separating 98% of those tested.

A critical evaluation of fasted state simulating gastric fluid (FaSSGF) that contains sodium lauryl sulfate and proposal of a modified recipe.

The aim of this work is to evaluate one of the most commonly used fasted state simulating gastric fluids (FaSSGFs), which contains sodium lauryl sulfate (SLS) (FaSSGF(SLS)), and propose a more appropriate surfactant concentration. Surface tension studies clearly show that the critical micelle concentration (CMC) of SLS in the relevant media (a media whose pH and sodium chloride concentration are representative of physiological conditions) is significantly lower (p<0.05) than 8.

Enantiomeric separation of mineralocorticoid receptor (hMR) antagonists using the Chiralcel OJ-H HPLC column with novel polar cosolvent eluent systems.

This study demonstrates the increased versatility of the Chiralcel OJ-H stationary phase when using various alcohol/acetonitrile mobile phases. This chiral stationary phase has traditionally been employed in the normal phase mode and more recently with neat alcohols as eluents. Selected isomeric human mineralocorticoid receptor (hMR) antagonist pharmaceutical candidates and synthetic intermediates were separated using the Chiralcel OJ-H HPLC column with novel polar cosolvent eluent systems.

Analysis of mannitol in pharmaceutical formulations using hydrophilic interaction liquid chromatography with evaporative light-scattering detection.

This study demonstrates the use of hydrophilic interaction liquid chromatography (HILIC) for the separation of both active and inactive ingredients in pharmaceuticals from a single injection. Excipients commonly used in parenteral formulations were separated using a gradient method employing increasing aqueous composition. An evaporative light-scattering detector (ELSD) provided direct detection of inactive excipients and inorganic salts lacking UV chromophores.

Evaluation of a monolithic silica column operated in the hydrophilic interaction chromatography mode with evaporative light scattering detection for the separation and detection of counter-ions.

In this work a monolithic silica column operated in the hydrophilic interaction chromatography (HILIC) mode in conjunction with an evaporative light scattering detector (ELSD) was investigated. Lithium, sodium and potassium were used as the test counter-ions for this evaluation. Chromatographic properties of this column operated in the HILIC mode were determined by varying key mobile phase parameters, such as pH, flow rate, buffer strength, acid and organic modifier.

Enantiomeric separation of dansyl amino acids using macrocyclic antibiotics as chiral mobile phase additives by narrow-bore high-performance liquid chromatography.

Seven macrocyclic antibiotics were evaluated as chiral selectors for the enantiomeric separation of 11 dansyl amino acids using narrow-bore high-performance liquid chromatography (HPLC). The macrocyclic antibiotics were incorporated as mobile phase additives to determine the enantioselective effects on the chiral analytes. The resolution and capacity factor (k') of each analyte were assessed while varying the structure of macrocyclic antibiotic and the mobile phase buffer pH.

Chiral separations of polar compounds by hydrophilic interaction chromatography with evaporative light scattering detection.

The chiral separations of drug substances and underivatized amino acids were demonstrated in this study through the use of hydrophilic interaction chromatography (HILIC). The polar character of the model compounds presented challenges for their analysis by traditional modes of chromatography, but through the employment of multimodal chromatography utilizing the HILIC mechanism and cyclodextrin- or teicoplanin-derivatized stationary phases, effective resolution was achieved. The analytes lacked sufficient ultraviolet chromophores, requiring their determination by evaporative light scattering detection.

Enantiomeric separations of dansyl amino acids using the macrocyclic antibiotic A35512B as a chiral selector in capillary electrophoresis.

The macrocyclic antibiotic A35512B was examined as a chiral selector for capillary electrophoresis (CE) using thirteen racemic dansyl amino acids as test analytes. The chiral selectivity of A35512B was evaluated as a function of the run buffer pH, antibiotic concentration, and organic modifier composition. After optimizing these parameters, the macrocylic antibiotic A35512B provided high resolutions of all the enantiomers for the thirteen dansyl amino acids tested in this study.

Evaluation of the macrocyclic antibiotic LY333328 as a chiral selector when used as a mobile phase additive in narrow bore HPLC.

The macrocyclic antibiotic LY333328 has been evaluated as a chiral selector for the enantioseparation of nine dansylated amino acids. This macrocyclic glycopeptide was used as a chiral mobile phase additive (CMPA) in conjunction with narrow bore high-performance liquid chromatography (HPLC). The key mobile phase parameters of LY333328 concentration and buffer pH were varied, along with variations in stationary phases consisting of C8, phenyl, cyano, and silica.

Statistical method for quantifying mobile phase selectivity in one- and two-dimensional overpressured layer chromatography.

A method for selecting mobile phases for either one-dimensional (1-D) or two-dimensional (2-D) planar chromatography is described and is applied to the separation of steroids by overpressured layer chromatography [Formula: see text] a form of forced-flow thin-layer chromatography [Formula: see text] using both normal- and reversed-phase chromatography. Two metrics are used for evaluating the separation quality of simulated chromatograms for each of 100 (or more) subsets of a set of 30 steroids in each of 15 1-D, and 105 2-D systems. The subsets vary in size between five and 25 steroids.

Stability of fluoxetine hydrochloride in fluoxetine solution diluted with common pharmaceutical diluents.

The stability of fluoxetine hydrochloride in fluoxetine solution diluted with five common pharmaceutical diluents was studied. Fluoxetine syrup, containing fluoxetine 4 mg/mL (as the hydrochloride salt), was diluted to 1 and 2 mg/mL in each of the following: deionized water; Simple Syrup, British Pharmacopeia; Simple Syrup, USP; Aromatic Elixir, USP; and grape-cranberry drink. Each solution was divided into eight 120-mL amber glass bottles: four stored at 5 degrees C and four stored at 30 degrees C.

The significance of the concordance rate for type 1 (insulin-dependent) diabetes in identical twins.

We studied prospectively 49 non-diabetic identical twins of recently-diagnosed Type 1 (insulin-dependent) diabetic patients for up to 24 years (median 9 years). During this time 15 developed Type 1 diabetes. Actuarial analysis indicates that by 12 years 34% of the twins will have developed Type 1 diabetes and that thereafter only another 2% will do so.

Blood sampling techniques in reptiles.

Disposition of the superficial blood vessels was studied in 38 species of reptiles with a view to examining their suitability for taking blood samples. It was concluded that the coccygeal veins were probably the most suitable for this purpose and the precise techniques for sampling from the different orders are described.