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Small tablets for implantation into the subconjunctival space in the eye are being developed to inhibit scarring after glaucoma filtration surgery (GFS). There is a need to evaluate drug dissolution at the molecular level to determine how the chemical structure of the active may correlate with dissolution in the nonsink conditions of the conjunctival space. We conducted molecular dynamics simulations to study the dissolution process of tablets derived from two drugs that can inhibit fibrosis after GFS, 5-fluorouracil (5-FU) and the matrix metalloprotease inhibitor (MMPi), ilomastat. The dissolution was simulated in the presence of simple point charge (SPC) water molecules, and the liquid turnover of the aqueous humor in the subconjunctival space was simulated by removal of the dissolved drug molecules at regular intervals and replacement by new water molecules. At the end of the simulation, the total molecular solvent accessible surface area of 5-FU tablets increased by 60 times more than that of ilomastat as a result of tablet swelling and release of molecules into solution. The tablet dissolution pattern shown in our molecular dynamic simulations tends to correlate with experimental release profiles. This work indicates that a series of molecular dynamic simulations can be used to predict the influence of the molecular properties of a drug on its dissolution profile and could be useful during preformulation where sufficient amounts of the drug are not always available to perform dissolution studies.

Abstract.We present comparative studies on the effect of varying the carboxylic-group content of thermally reduced graphene oxides (TRGs) on the anticorrosive properties of as-prepared poly(methyl methacrylate) (PMMA)/TRG composite (PTC) coatings. TRGs were formed from graphene oxide (GO) by thermal exfoliation. The as-prepared TRGs were then characterized using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Subsequently, the PTC materials were prepared via a UV-curing process and then characterized using FTIR spectroscopy and transmission electron microscopy (TEM). PTC coatings containing TRGs with a higher carboxylic-group content exhibited better corrosion protection of a cold-rolled steel electrode that those with a lower carboxylic-group content. This is because the well-dispersed TRG with a higher carboxylic-group content embedded in the PMMA matrix effectively enhances the oxygen barrier properties of the PTC. This conclusion was supported by gas permeability analysis.

Background A lower level of consciousness is a common presentation in critical care, with many different causes and contributory factors, of which more than one may be present concurrently. Case presentation We described a woman with poorly controlled diabetes and steroid-dependent asthma who presented in a deep coma. She was found to have Streptococcus intermedius bacteremia and pyogenic ventriculitis that originated from right middle lobe pneumonia. Also, multiple small parenchymal lesions were observed on brain magnetic resonance imaging and increased protein concentration was noted in cerebral spinal fluid. Initially, her coma was thought to be due to diabetic ketoacidosis and septic encephalopathy. However, her lowered level of consciousness was disproportionate to either diabetic ketoacidosis or septic encephalopathy, and her clinical course was not as expected for these two conditions. Treatment with antibiotic, corticosteroid and antihelminthic drugs was administered resulting in improving consciousness. The Streptococcus intermedius pneumonia progressed to form a large cavity that needed an early surgical lobectomy and resulted in the unexpected diagnosis of chronic cavitary pulmonary aspergillosus. Conclusions In critical care, a lowered level of consciousness may have many etiologies, and critical care clinicians should be familiar with the signs and symptoms of all possible causes to enable prompt diagnosis and appropriate treatment.