Magnetic resonance imaging study on the physical stability of menthol and diphenhydramine cream for the treatment of chronic kidney disease-associated pruritus.

A cream that contains menthol and diphenhydramine is widely prepared in hospital pharmacies and prescribed to patients for the treatment of pruritus associated with chronic kidney disease. However, there is a serious concern regarding its physical stability; therefore, we investigated this issue using magnetic resonance imaging (MRI). For a sample preparation, a menthol-containing ethanol solution was mixed with a commercial diphenhydramine cream. After storage for 7 d at 40°C, substantial phase separation into two distinct layers (upper and lower layers) was observed in the sample. This study further examined the components of the phase-separated layers using magnetic resonance (MR) spectroscopy and chemical shift selective images, and it was verified that the upper layer consisted of packed oil droplet layers, whereas the lower was an aqueous phase. Subsequently, the time-dependent phase separation of the sample at different temperatures was investigated. From the MR images, including a T2 relaxation time map and apparent diffusion coefficient maps, it was obvious that the phase separation developed further with increasing temperature; the most substantial phase separation was observed from the sample stored at 40°C, while no phase separation was detected at 25°C. In the final phase of this study, we conducted a formulation study and succeeded in improving the cream's physical stability by adding a hydrophilic surfactant to the preparation.

[Deceased Schizophrenic Patients--Focus on QT Prolongation].

We retrospectively evaluated factors affecting the lifespan of schizophrenic patients, who are known to have a shorter life expectancy than healthy people, focusing on the relationship with QT prolongation associated with antipsychotics. In a total of 406 patients who died at Asai Hospital the mean age at death was compared between schizophrenic patients and nonpsychiatric patients. In deceased schizophrenic patients, drug-related factors, hematology results, and electrocardiographic findings for 3 years before death were compared with those for the same period in age-matched surviving schizophrenic patients. In addition, QT values in schizophrenic patients and healthy controls were evaluated by age group. The mean age at death was significantly younger in schizophrenic patients (63.4 +/- 2.63 years) than in nonpsychiatric patients (84.0 +/- 0.57 years) (p<0.001). Bivariate analysis between deceased and surviving schizophrenic patients showed significant differences in QT values at 2 years, 1 year, and 0.5 years before death and in AST and ALT values at 0.5.years before death. The incidence of QT prolongation in deceased schizophrenic patients (52.0%) was about twice as high as that in surviving schizophrenic patients (24.5%). Multiple logistic regression analysis suggested that the proportion of deceased patients was higher when QT intervals were longer and ALT values were relatively higher, even if within the normal range. In both schizophrenic patients and medical checkup examinees, QT values were positively correlated with the age (R2 = 0.9061 and 0.9276, respectively), and QT intervals in schizophrenic patients were significantly longer in the 30- to 70-year age groups. In both schizophrenic patients and medical checkup examinees, QT values were positively correlated with the age, and QT intervals in schizophrenic patients were significantly longer than those in medical checkup examinees in the same age groups. Deceased schizophrenic patients showed significantly longer QT intervals from 2 years before death than age-matched surviving schizophrenic patients. QT prolongation may influence the lifespan of schizophrenic patients, which are shorter than those of nonpsychiatric patients. This highlights the importance of following electrocardiographic findings and hematology results of schizophrenic patients over time.