Development of udenafil-loaded microemulsions for intranasal delivery: in vitro and in vivo evaluations

To achieve rapid onset of action and improved bioavailability of udenafil, a microemulsion system was developed for its intranasal delivery. Phase behavior, particle size, transmission electron microscope (TEM) images, and the drug solubilization capacity of the microemulsion were investigated. A single isotropic region was found in pseudo-ternary phase diagrams developed at various ratios with CapMul MCM L8 as an oil, Labrasol as a surfactant, and Transcutol or its mixture with ethanol (1:0.25, v/v) as a cosurfactant. Optimized microemulsion formulations with a mean diameter of 120-154 nm achieved enhanced solubility of udenafil (>10 mg/ml) compared with its aqueous solubility (0.02 mg/ml). An in vitro permeation study was performed in human nasal epithelial (HNE) cell monolayers cultured by the air-liquid interface (ALI) method, and the permeated amounts of udenafil increased up to 3.41-fold versus that of pure udenafil. According to the results of an in vivo pharmacokinetic study in rats, intranasal administration of udenafil-loaded microemulsion had a shorter T_max value (1 min) compared with oral administration and improved bioavailability (85.71%) compared with oral and intranasal (solution) administration. The microemulsion system developed for intranasal administration may be a promising delivery system of udenafil, with a rapid onset of action and improved bioavailability.     

Benign form of herpes simplex encephalitis

A 34-year-old woman who presented with only severe headache for 12 days was reported. She was initially diagnosed with cerebral infarction of the right temporal lobe and treated with aspirin, without improvement. On admission, she had bilateral papilledema. Other findings were unremarkable. CT scan and MRI of the brain revealed an area of cerebritis at the right temporal lobe. Lumbar puncture showed high opening pressure with normal CSF profiles. The patient was treated with intravenous acyclovir which gave a favorable outcome.     

Opportunistic infections in myasthenia gravis treated with mycophenolate mofetil

Mycophenolate mofetil (MMF) is used for immunosuppression in myasthenia gravis (MG). Although there are numerous data on associated infection and prophylaxis in transplant patients who are on MMF, data in MG remains lacking. We report two elderly seropositive MG patients who developed cytomegalovirus (CMV) enteritis and Epstein-Barr virus (EBV) encephalitis while on MMF for 5months and 1year, respectively. Chronic MMF therapy in MG patients may trigger life-threatening infections including CMV and EBV diseases, especially in the elderly. Similar to the practice in transplant patients, viral serology testing and appropriate prophylactic regimen with antiviral agents should be considered, particularly in older MG patients.     

Chronic immune sensorimotor polyradiculopathy: Report of a case series

Repetitive nerve stimulation (RNS) of the median nerve is rarely studied in myasthenia gravis (MG). We performed a retrospective analysis of RNS studies performed on 448 patients at our center between 2010 and 2016. Among 95 patients with MG, an abnormal decrement of the compound muscle action potential amplitude was seen in 40.7% of median, 38.4% of spinal accessory, and 57.1% of facial nerve RNS studies. Median nerve RNS was abnormal in 10 patients with normal spinal accessory and 5 patients with normal facial nerve RNS. MG patients with abnormal median nerve RNS were more likely to be seropositive and have limb weakness. No differences were observed in the incidence of abnormal median nerve RNS in patients with and without a median neuropathy at the wrist. Median nerve RNS is easy to perform, reproducible, and should be considered in the electrodiagnostic evaluation of MG.