William Neil Charman

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When a young observer attempts to accommodate steadily on a fixed stimulus, the nominally steady-state response shows small instabilities or fluctuations (sometimes termed microfluctuations or oscillations). These fluctuations typically have an amplitude of a few tenths of a dioptre and a frequency spectrum extending up to a few Hertz. The properties of(More)
Highly potent, but poorly water-soluble, drug candidates are common outcomes of contemporary drug discovery programmes and present a number of challenges to drug development - most notably, the issue of reduced systemic exposure after oral administration. However, it is increasingly apparent that formulations containing natural and/or synthetic lipids(More)
Self-emulsifying drug delivery systems (SEDDSs) represent a possible alternative to traditional oral formulations of lipophilic compounds. In the present study, a lipophilic compound, WIN 54954, was formulated in a medium chain triglyceride oil/nonionic surfactant mixture which exhibited self-emulsification under conditions of gentle agitation in an aqueous(More)
Ozonide OZ439 is a synthetic peroxide antimalarial drug candidate designed to provide a single-dose oral cure in humans. OZ439 has successfully completed Phase I clinical trials, where it was shown to be safe at doses up to 1,600 mg and is currently undergoing Phase IIa trials in malaria patients. Herein, we describe the discovery of OZ439 and the(More)
An experiment is described in which the subjective depth-of-focus (DOF) of the eye, defined as the range of focusing errors for which the image of the target appears to have the same clarity, contrast, and form as the optimal in-focus image, was measured as a function of the size of high contrast (99%) Snellen Es for 5 trained subjects under cycloplegia.(More)
Monocular accommodation responses to stimuli at vergences from 0 to -4.5 D (i.e. effective object-eye distances from infinity to 22 cm) were measured objectively using artificial pupils of 0.5, 0.75, 1.0 and 3.0 mm diameters and a constant retinal illuminance of 7000 td. The slopes of the response/stimulus curves for the 0.75, 1.0 and 3.0 mm pupils agree(More)
The ocular modulation transfer function (MTF) has an important role in many investigations into human vision. It can be approximated by the equation MT = exp [-(SF/SFc)n], where MT, SF, SFc and n are the modulation transfer, spatial frequency, frequency constant and MTF index respectively. In a theoretical study, the parameters n and SFc were determined by(More)
In recent years there has been an increase in interest in the utility of lipid based delivery systems, at least in part as a result of the effective development of lipid based products such as Sandimmun Neoral (cyclosporin), Norvir (ritonavir) and Fortovase (saquinavir). The development pathway for lipid based formulations, however, is still largely(More)
Postprandial administration of halofantrine (Hf), an important antimalarial, leads to 3- and 12-fold increases in oral bioavailability in humans and beagles, respectively, and corresponding 2.4-fold and 6.8-fold decreases in metabolic conversion to desbutylhalofantrine (Hfm). Factors contributing to the decreased postprandial metabolism of Hf could include(More)
The intestinal mucosa is capable of metabolising drugs via phase I and II reactions. Increasingly, as a result of in vitro and in vivo (animal and human) data, the intestinal mucosa is being implicated as a major metabolic organ for some drugs. This has been supported by clinical studies of orally administered drugs (well-known examples include cyclosporin,(More)