In vitro autoradiography and in vivo evaluation in cynomolgus monkey of [18F]FE-PE2I, a new dopamine transporter PET radioligand

Synapse ◽  
2009 ◽  
Vol 63 (10) ◽  
pp. 871-880 ◽  
Author(s):  
Andrea Varrone ◽  
Carsten Steiger ◽  
Magnus Schou ◽  
Akihiro Takano ◽  
Sjoerd J. Finnema ◽  
...  

2005 ◽  
Vol 14 (9) ◽  
pp. 655-663 ◽  
Author(s):  
Motoki Inaji ◽  
Takahito Yoshizaki ◽  
Takashi Okauchi ◽  
Jun Maeda ◽  
Yuji Nagai ◽  
...  

Positron emission tomography (PET) is a useful tool to assess and visualize neurotransmissions in vivo. In this study, we performed repeated PET scans with [11C]PE2I, a tracer of the dopamine transporter, to evaluate the alteration of the expression of dopamine (DA) transmission component after a fetal mesencephalic transplantation. The fetal mesencephalic cells were transplanted into the striatum of unilateral 6-OHDA-lesioned rats. PET scans with [11C]PE2I were performed to evaluate the DA transporter before and 2 and 4 weeks after the transplantation. Rotation behavior tests, in vitro autoradiography, measurements of DA contents in the striatum by high-performance liquid chromatography (HPLC), and tyrosine hydroxylase (TH) immuno-histological examinations were performed at the same time points and examined for their relationship to changes in the dopamine transporter. The number of ipsilateral rotations induced by methamphetamine injections decreased. DA contents in the striatum measured with HPLC significantly increased. In the PET study, the binding potential of [11C]PE2I increased at 4 weeks. The results of the in vitro autoradiography study corresponded with those of the PET study. The degrees of the change in the binding potentials correlated with those of the numbers of rotations in the behavioral study and the DA contents in the striatum. In the histological examination, TH-positive cells with axons were observed at 2 and 4 weeks after the transplantation. As the dopamine transporter exists only in the axon terminal of DA neurons, these results suggested that PET measurements of [11C]PE2I binding indicated not only survival, but maturity and functioning of the transplanted cells. Repeated PET measurements of DA transporters are a useful tool in assessing the effectiveness of neural transplantations.



NeuroImage ◽  
2008 ◽  
Vol 41 ◽  
pp. T144
Author(s):  
Andrea Varrone ◽  
M. Schou ◽  
C. Steiger ◽  
A. Takano ◽  
S. Finnema ◽  
...  




Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
J Bauer ◽  
F Dehm ◽  
A Koeberle ◽  
F Pollastro ◽  
G Appendino ◽  
...  


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.



Author(s):  
Y. Srinivasa Rao ◽  
K. Adinarayana Reddy

Fast dissolving oral delivery systems are solid dosage forms, which disintegrate or dissolve within 1 minute in the mouth without drinking water or chewing. Mouth dissolving film (MDF) is a better alternate to oral disintegrating tablets due to its novelty, ease of use and the consequent patient compliance. The purpose of this work was to develop mouth dissolving oral films of palonosetron HCl, an antiemetic drug especially used in the prevention and treatment of chemotherapy-induced nausea and vomiting. In the present work, the films were prepared by using solvent casting method with various polymers HPMC E3, E5 & E15 as a film base synthetic polymer, propylene glycol as a plasticizer and maltodextrin and other polymers. Films were found to be satisfactory when evaluated for thickness, in vitro drug release, folding endurance, drug content and disintegration time. The surface pH of all the films was found to be neutral. The in vitro drug release of optimized formulation F29 was found to be 99.55 ± 6.3 7% in 7 min. The optimized formulation F29 also showed satisfactory surface pH, drug content (99.38 ± 0.08 %), disintegration time of 8 seconds and good stability. FTIR data revealed that no interaction takes place between the drug and polymers used in the optimized formulation. In vitro and in vivo evaluation of the films confirmed their potential as an innovative dosage form to improve delivery and quick onset of action of Palonosetron Hydrochloride. Therefore, the mouth dissolving film of palonosetron is potentially useful for the treatment of emesis disease where quick onset of action is desired, also improved patient compliance.



Author(s):  
Bhikshapathi D. V. R. N. ◽  
Kanteepan P

Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. The current research study aimed to develop novel gastro-retentive mucoadhesive microspheres of rebamipide using ionotropic gelation technique. Studies of micromeritic properties confirmed that microspheres were free flowing with good packability. The in vitro drug release showed the sustained release of rebamipide up to 99.23 ± 0.13% within 12 h whereas marketed product displayed the drug release of 95.15 ± 0.23% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer-Peppas (R2 = 0.915, 0.969), respectively. The optimized M12 formulation displayed optimum features, such as entrapment efficiency 97%, particle size 61.94 ± 0.11 µm, percentage yield 98%, swelling index 95% and mucoadhesiveness was 97%. FTIR studies revealed no major incompatibility between drug and excipients. SEM confirmed the particles were of spherical in shape. Optimized formulation (M12) were stable at 40°C ± 2°C/75% RH ± 5% RH for 6 months. In vivo studies were performed and kinetic parameters like Cmax, Tmax, AUC0-t, AUC0-∞, t1/2, and Kel  were calculated. The marketed product Cmax (3.15 ± 0.05 ng/mL) was higher than optimized formulation (2.58 ± 0.03 ng/mL). The optimized formulation AUC0-t (15.25 ± 1.14 ng.hr/mL), AUC0-∞ (19.42 ± 1.24 ng.hr/mL) was significantly higher than that of marketed product AUC0-t (10.21 ± 1.26 ng.hr/mL) and AUC0-∞ (13.15 ± 0.05 ng.hr/mL). These results indicate an optimized formulation bioavailability of 2.5-fold greater than marketed product.  



2019 ◽  
Vol 20 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Chi Zhang ◽  
Zhichun Gu ◽  
Long Shen ◽  
Xianyan Liu ◽  
Houwen Lin

Background: To deliver drugs to treat Alzheimer’s Disease (AD), nanoparticles should firstly penetrate through blood brain barrier, and then target neurons. Methods: Recently, we developed an Apo A-I and NL4 dual modified nanoparticle (ANNP) to deliver beta-amyloid converting enzyme 1 (BACE1) siRNA. Although promising in vitro results were obtained, the in vivo performance was not clear. Therefore, in this study, we further evaluated the in vivo neuroprotective effect and toxicity of the ANNP/siRNA. The ANNP/siRNA was 80.6 nm with good stability when incubated with serum. In vivo, the treatment with ANNP/siRNA significantly improves the spatial learning and memory of APP/PS1 double transgenic mice, as determined by mean escape latency, times of crossing the platform area during the 60 s swimming and the percentage of the distance in the target quadrant. Results and Conclusion: After the treatment, BACE1 RNA level of ANNP/siRNA group was greatly reduced, which contributed a good AD treatment outcome. Finally, after repeated administration, the ANNP/siRNA did not lead to significant change as observed by HE staining of main organs, suggesting the good biocompatibility of ANNP/siRNA. These results demonstrated that the ANNP was a good candidate for AD targeting siRNA delivery.



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