scholarly journals An Amperometric Glucose Sensor Integrated into an Insulin Delivery Cannula: In Vitro and In Vivo Evaluation

2017 ◽  
Vol 19 (4) ◽  
pp. 226-236 ◽  
Author(s):  
W. Kenneth Ward ◽  
Gabriel Heinrich ◽  
Matthew Breen ◽  
Sheila Benware ◽  
Nicole Vollum ◽  
...  
2019 ◽  
Vol 572 ◽  
pp. 118710 ◽  
Author(s):  
Fatemeh Mohammadpour ◽  
Farzin Hadizadeh ◽  
Mohsen Tafaghodi ◽  
Kayvan Sadri ◽  
Amir Hooshang Mohammadpour ◽  
...  

1994 ◽  
Vol 17 (2) ◽  
pp. 88-94 ◽  
Author(s):  
F. Moussy ◽  
D.J. Harrison ◽  
R.V. Rajotte

We have developed an implantable glucose sensor based on a new tri-layer membrane configuration. The needle-type sensor integrates a Pt working electrode and a Ag/AgCI reference electrode. Its size is equivalent to a 25 gauge needle (0.5 mm in diamater). Poly (o-phenylenediamine) was used as an inner coating to reduce interference by small compounds present in the body fluids, and the perfluorinated ionomer, Nation as a biocompatible, protective, outer coating. Glucose oxidase trapped in an albumin/glutaraldehyde matrix was sandwiched between these coatings. In vitro tests in buffer showed the sensors had a good selectively, a sensitivity of about 25 nA/mM, and a 90% response time of 33 s. Stabilization of the current following polarization required 10 to 30 min in vitro and 30 to 40 in vivo. Although these sensors remained stable for many weeks in saline solution, their implantation in animals resulted in the degradation of the protective Nation outer coating, which in turn, led to the failure of the incorporated reference electrode. We demonstrated that if unprotected, the AgCI layer of the reference electrode rapidly dissolves in the biological environment. However, we later showed that in vivo degradation of Nation can be prevented by heat curing. When heat cured sensors were subcutaneously implanted in dogs, the sensors' signal closely followed the plasma glucose level during glucose tolerance tests. The response of the sensors implanted in dogs was retained for 10 days.


2010 ◽  
Vol 21 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Claudia R. Gordijo ◽  
Khajag Koulajian ◽  
Adam J. Shuhendler ◽  
Leonardo D. Bonifacio ◽  
Hui Yu Huang ◽  
...  

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.


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