PBPK modeling coupled with biorelevant dissolution to forecast the oral performance of amorphous solid dispersion formulations.

The aim of this research was to develop an in silico modeling and simulation approach to predict the oral performance of a poorly soluble drug candidate, T2CP, formulated as an amorphous solid dispersion and an amorphous powder. The dissolution and precipitation profiles of T2CP of the two amorphous formulations were evaluated in biorelevant media using USP 2 paddle apparatus. Three equations, the Noyes-Whitney equation for dissolution and separate equations describing nucleation and crystal growth, were fitted simultaneously to the in vitro profiles to estimate the dissolution and precipitation parameters for each formulation. The in silico prediction model for the amorphous formulations was designed using STELLA Professional software and the simulated profiles were compared with the observed plasma profiles in dogs. The STELLA model was able to describe the complex characteristics of in vitro dissolution and precipitation of the amorphous formulations well. The predicted plasma concentration profiles using the estimated dissolution and precipitation parameters of the two amorphous formulations were close to the profiles observed in dogs. This research paves the way for further application of biorelevant in vitro methods in combination with in silico tools to mechanistically forecast the in vivo performance of enhanced formulations.

Simultaneous development of Kawasaki disease following acute human adenovirus infection in monozygotic twins: A case report.

BACKGROUND: The etiology of Kawasaki disease (KD) remains unknown. However, many studies have suggested that specific genetic factors and/or some infectious agents underlie the onset of KD. Previous studies have suggested that human adenovirus (HAdV) is one of the triggering pathogens of KD. Here, we report monozygotic twin boys who sequentially developed KD in conjunction with acute HAdV type 3 (HAdV-3) infection. CASE PRESENTATION: The patients were four-year-old monozygotic twin boys. The elder brother developed a high fever and was diagnosed with HAdV infection with an immunochromatographic kit for HAdV (IC-kit). He was transferred to our institute after persistent fever for 7 days. On admission, he already fulfilled all the diagnostic criteria for KD. His laboratory data were as follows: WBC, 9700/µl; CRP, 2.42 mg/dl; IFN-γ, 99.8 pg/ml; and TNF-α, 10.9 pg/ml. He received intravenous immunoglobulin (IVIG) and aspirin and responded well, with no coronary artery abnormalities. The younger brother, who was also IC-kit-positive, was hospitalized on the same day as his elder brother after persistent fever for 3 days. His data on admission were as follows: WBC, 12,600/µl; CRP, 5.54 mg/dl; IFN-γ, 105.0 pg/ml; and TNF-α, 33.6 pg/ml. Although he developed all of the typical KD symptoms by day 4, his fever subsided spontaneously on day 6 without IVIG or aspirin. However, he developed a dilation of the coronary artery in the region of the left circumflex artery bifurcation on day 10. His coronary artery dilation had resolved 3 months after onset. HAdV-3 DNA was detected with PCR in stool samples from both patients, and HAdV3 was isolated from the younger brother's stool sample. Serum neutralizing antibodies to AdV3 were also significantly elevated in both patients, suggesting seroconversion. CONCLUSIONS: There have been few reports of the simultaneous development of KD in monozygotic twins. Notably, both twins had an acute HAdV-3 infection immediately before they developed KD. These cases strongly suggest that KD was triggered by HAdV-3 infection, and they indicate that specific immune responses to some pathogens (such as HAdV-3), arising from genetic susceptibility, play a critical role in the pathogenesis of KD.

Protective effects of influenza A (H1N1) pandemic 2009 vaccination against the onset of influenza-like illness and asthma exacerbation in Japanese children.

BACKGROUND: Vaccination against influenza A(H1N1)pdm09 in Japan started in October 2009. Children with asthma are considered as a high-risk group and are recommended to preferentially receive the vaccine. OBJECTIVE: To identify the clinical effects of vaccination in Japanese children with and without asthma. METHODS: We conducted a cross-sectional, questionnaire-based survey to compare vaccination rates, vaccine effectiveness against physician-diagnosed influenza A infection (PDIA), and consecutive asthma exacerbations between children with and without asthma. RESULTS: Of the 460 children included in this study, those with asthma had higher vaccination rates (46.5%, 67/144) than those without asthma (30.4%, 96/316). Influenza A infections were diagnosed in 28 of 163 vaccinated children (17.2%) compared to 164 of 297 unvaccinated children (55.2%, p < 0.001). Comparison of positive influenza diagnosis rates between vaccinated and unvaccinated children with and without asthma showed that unvaccinated children with asthma had an elevated odds ratio (13.235; 95% confidence interval [CI], 5.564-32.134) and that treatment for asthma exacerbations was needed in a larger proportion of unvaccinated children. Vaccine effectiveness against PDIA was 87% (95% CI, 78-93%) overall, 92% (95% CI, 81-96%) in children with asthma and 81% (95% CI, 63-91%) in children without asthma, respectively. CONCLUSIONS: The administration of an inactivated, split-virus, non-adjuvanted monovalent A(H1N1)pdm09 vaccine during the pandemic period reduced the number of physician-diagnosed influenza A infections and asthma exacerbations in children with asthma. Therefore, we strongly recommend that high-risk children with a history of asthma receive vaccines during pandemics.

Influence of binder droplet dimension on granulation rate during fluidized bed granulation.

Here, we statistically identified the critical factor of the granulation rate during the fluidized bed granulation process. Lactose was selected as the excipient and was granulated with several binders, including hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and polyvinylpyrrolidone. The viscosity, density, and surface tension of the binder solution, contact angle, and the work done during adhesion and cohesion between the binder and lactose, mist diameter, Stokes number, and the dimension of the droplet were considered. The Stokes number was defined as the ratio of the inertial force to the viscous-damping force of a particle. We confirmed that droplet diameter after adhesion had the highest correlation coefficient with the granulation rate constant in our investigated parameters. Partial least squares regression revealed two critical principal components of the granulation rate: one relating to the droplet dimension, which is composed of mist diameter and diameter and thickness of the droplet after adhesion of the binder to the lactose surface; and the other relating to wettability, which involves the work done during adhesion and cohesion, surface tension, and the thickness of the droplet after adhesion of the binder to the lactose surface.

Evaluation of models for predicting spray mist diameter for scaling-up of the fluidized bed granulation process.

We evaluated models for predicting spray mist diameter suitable for scaling-up the fluidized bed granulation process. By precise selection of experimental conditions, we were able to identify a suitable prediction model that considers changes in binder solution, nozzle dimension, and spray conditions. We used hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), or polyvinylpyrrolidone (PVP) binder solutions, which are commonly employed by the pharmaceutical industry. Nozzle dimension and spray conditions for oral dosing were carefully selected to reflect manufacturing and small (1/10) scale process conditions. We were able to demonstrate that the prediction model proposed by Mulhem optimally estimated spray mist diameter when each coefficient was modified. Moreover, we developed a simple scale-up rule to produce the same spray mist diameter at different process scales. We confirmed that the Rosin-Rammler distribution could be applied to this process, and that its distribution coefficient was 1.43-1.72 regardless of binder solution, spray condition, or nozzle dimension.

Outcomes of childhood pulmonary arterial hypertension in BMPR2 and ALK1 mutation carriers.

Mutations in the bone morphogenetic protein receptor type 2 (BMPR2) gene and the activin receptor-like kinase 1 (ALK1) gene have been reported in heritable pulmonary arterial hypertension (HPAH) and idiopathic pulmonary arterial hypertension (IPAH). However, the relation between clinical characteristics and each gene mutation in IPAH and HPAH is still unclear, especially in childhood. The aim of this study was to determine, in a retrospective study, the influence and clinical outcomes of gene mutations in childhood IPAH and HPAH. Fifty-four patients with IPAH or HPAH whose onset of disease was at <16 years of age were included. Functional characteristics, hemodynamic parameters, and clinical outcomes were compared in BMPR2 and ALK1 mutation carriers and noncarriers. Overall 5-year survival for all patients was 76%. Eighteen BMPR2 mutation carriers and 7 ALK1 mutation carriers were detected in the 54 patients with childhood IPAH or HPAH. Five-year survival was lower in BMPR2 mutation carriers than mutation noncarriers (55% vs 90%, hazard ratio 12.54, p = 0.0003). ALK1 mutation carriers also had a tendency to have worse outcome than mutation noncarriers (5-year survival rate 64%, hazard ratio 5.14, p = 0.1205). In conclusion, patients with childhood IPAH or HPAH with BMPR2 mutation have the poorest clinical outcomes. ALK1 mutation carriers tended to have worse outcomes than mutation noncarriers. It is important to consider aggressive treatment for BMPR2 or ALK1 mutation carriers.

[Analysis of genetic mutation and modifier genes in pulmonary arterial hypertension].

Mutations of the bone morphogenetic protein receptor II gene (BMPR2) have been reported in patients with pulmonary arterial hypertension (PAH). In hereditary hemorrhagic telangiectasia (HHT) patients with PAH, missense mutations of the activin receptor-like kinase 1 gene (ALK1) located in the serine-threonine kinase domain. Recently, the mutations of ALK1 in the serine-threonine kinase domain were observed in PAH patients. ALK1 mutations play a critical role in PAH without HHT as well as in PAH with HHT. Because only 10-20% carriers with BMPR2 mutations develop PAH, the existence of environmental factors or modifier genes as 5-HTT(serotonin transporter) and ACE (angiotensin converting enzyme) is highly probable.

Implications of mutations of activin receptor-like kinase 1 gene (ALK1) in addition to bone morphogenetic protein receptor II gene (BMPR2) in children with pulmonary arterial hypertension.

BACKGROUND: Mutations of the bone morphogenetic protein receptor II gene (BMPR2), and 1 mutation of the activin receptor-like kinase 1 gene (ALK1) have been reported in patients with pulmonary arterial hypertension (PAH). METHODS AND RESULTS: A genomic study of ALK1 and BMPR2 was conducted in 21 PAH probands under 16 years of age to study the relationship between the clinical features of the patients and these genes. In all 4 familial aggregates of PAH, 3 ALK1 or 1 BMPR2 mutations were identified. Among 17 probands aged between 4 and 14 years with idiopathic PAH, 2 ALK1 mutations (2/17: 11.8%) and 3 BMPR2 mutations (3/17: 17.6%; 5 mutations in total: 5/17: 29.4%) were found. CONCLUSION: Each proband with the ALK1 mutation developed PAH, as did the probands with the BMPR2 mutation. Hence, it is proposed that ALK1 plays as notable a role as BMPR2 in the etiology of PAH. Furthermore, asymptomatic carriers with the ALK1 mutation within the serine - threonine kinase domain are at risk of developing PAH and hereditary hemorrhagic telangiectasia, so close follow-up is recommended for those individuals.

Abnormal tissue doppler images are associated with elevated plasma brain natriuretic peptide and increased oxidative stress in acute Kawasaki disease.

BACKGROUND: The aims of this study were to evaluate myocardial mechanics using pulsed tissue Doppler imaging (TDI), and to determine the relationship between abnormal myocardial performance and plasma brain natriuretic peptide (BNP) levels and oxidative stress in acute Kawasaki disease (KD). METHODS AND RESULTS: Consecutive TDI parameters, including peak systolic velocity (Sw) and early (Ew) and late diastolic excursion of the mitral annuli were obtained in 42 patients with KD (mean age: 2.4+/-0.4 years) in weeks 1, 2, and 3, and during convalescence. Plasma BNP level and urinary 8-isoprostane were also examined during the acute phase. These data were then compared with TDI profiles from 62 healthy children, plasma BNP levels in 38 controls with other febrile illnesses, and urinary 8-isoprostane levels in 13 healthy children. Ew in week 1 was significantly lower than in controls, subsequently normalizing in the convalescent stage. Plasma BNP level in acute KD patients was significantly higher (65+/-9 pg/ml) than in controls (13+/-2 pg/ml). Urinary 8-isoprostane level in acute KD patients was significantly higher as compared with control (596 +/-37 vs 379+/-26 pg/ml Cr, p<0.05). There was a significant negative correlation between week 1 Sw and plasma BNP level (r=-0.55, p=0.0001). Change in Sw velocity in the BNP >/=51 group was significantly greater than in the BNP <51 group. There was a significant negative correlation between week 1 Sw and urinary 8-isoprostane level (r=-0.48, p=0.001). CONCLUSIONS: Latent abnormal tissue Doppler profiles, possibly reflecting long-axis systolic and diastolic dysfunction have been noted in KD patients. Abnormal myocardial mechanics may contribute to the increased plasma BNP level and enhanced oxidative stress may contribute to cardiac dysfunction in KD.