Multi-year study with the university of Zurich

In a multi-year study with the University of Zurich, not only was the effective transport with Vetdrop TDA investigated, but the positive effect of the system on degenerative cartilage structures was also examined.

A publicly funded study on the effect of TDA treatments on degenerative joint diseases and cartilage problems began in early 2010. The study was conducted at the University of Zurich on 34 sheep. A severe defect was induced into the knee joint cartilage and then so-called "microfractures" were punched into the bone. This structure was used in several previous studies and induces a manifest joint arthrosis within a few weeks. 
 
The animals were divided into six comparison groups and treated with Vetdrop TDA for six weeks and in one comparison group with a systemic standard therapy (intravenous drug administration). Another group served as reference and was treated only initally. The four TDA groups were treated with different formulations in the TDA system (3 times weekly), the systemically treated group with carprofen i.v. carprofen was also the indicator substance in the investigations. The blood levels of the animals were checked every two days, the joint levels initially more frequently and later weekly. In addition, the pain behaviour of the animals was also documented and examined. Six weeks after the last treatment (12 weeks after surgery) the animals were sacrificed and examined for changes in the cartilage and bone of the manipulated joint. 
 
The study was sponsored by the Swiss national innovation agency CTI and was conducted according to the highest ethical standards. It was subject to the control of the Swiss Ethics Committee. The animals were of the same origin and age and were raised under identical conditions. They could be used as animal feed due to the low systemic exposure.
The results are clear:

The indicator substance carprofen reached the joint center (synovial fluid) 

already after the first TDA application.

Reproducible and effective levels were achieved.

The observed pain behaviour of the vetdrop TDA treated animals was better than in the control groups.

The ratio between systemic and local drug levels was 7-8 times better with TDA than with systemic therapy.

The ratio between systemic and local drug levels was 7-8 times better with TDA than with systemic therapy.

The indicator substance was identical in both groups - carprofen. Carprofen is an anti-inflammatory drug that is currently only available in systemic administration. All the more astonishing is the achieved difference in defect between the TDA-carprofen group and the carprofen-i.v. group. Interestingly, even the animals treated neutrally (without active ingredient) with the TDA system performed better than their i.v. carprofen-treated conspecifics - although carprofen is said to have a positive effect on cartilage structuring.

Study at the university of Zürich

Concentration analyses and pharmacokinetic considerations of transdermal application of carprofen using a novel application technique 
fromFouché, Nathalie Elisa, 2012 (DE)