Our History of Innovation

InterAg has a long history of successful R&D and has commercialised a number of novel controlled release drug delivery technologies for animal health and reproduction. From the early 1980s. InterAg employed a large team of scientists, technicians and graduate students and formed international collaborations that provided R&D expertise in the areas of intravaginal, intramammary, injectable and intraruminal routes for drug administration. A large portfolio of patents and scientific publications resulted from this work; some examples are described below.

CIDR Inserts

A major R&D programme was conducted in the 1980s in drug release from polymers over a number of years that lead to the design and formulation and FDA registration of DEC’s current 1380 CIDR® (Controlled Internal Drug Release) insert product, which is market leader for the control of estrus in dairy cattle in the USA and a number of other countries around the world. The CIDR insert is a registered trademark of InterAg NZ and is licenced to Zoetis. It is a single use device, used to deliver progesterone intravaginaly to cows, sheep and goats in order to provide control over the oestrus cycle, through the controlled release of progesterone.

The CIDR insert is a T shaped device that consists of a nylon spine, over which an elastic silicone skin is injection moulded. The two arms of the ‘T’ or “wings” can be folded together in order to facilitate insertion into the vaginal cavity and also to promote retention after insertion. A tail is attached to the base of the CIDR insert to enable removal from the vagina after treatment. The skin (consisting of an elastic silicone rubber) serves as a matrix for the active ingredient, progesterone.

Pig CIDR® Insert

The Pig CIDR® insert is a patented intravaginal drug delivery system containing progesterone for the control of the estrous cycle in pigs. It represents the only successful development of an intravaginal insert in the world for use in pigs, demonstrated through clinically effective animal trials conducted in the USA.

The product has applications in the gilt market for estrous control (synchronization of estrus, induction of ovulation, possible induction of puberty and potential increase in litter size) and the sow market for estrous control (synchronization of estrus and induction of ovulation).

Rumenal Drug Delivery Device

The Rumenal Drug Delivery Device was developed for delivery of active compounds to the rumen of animals. The device has the ability to provide accurate doseing rates, precise delivery regimes and flexible formulation. Applications include the continuous release of high value bioactives into the rumen or as a reservoir for the controlled delivery of post ruminal protein and peptides.

Biodegradable Intravaginal Device

This device was developed as biodegradable alternative to the use of the silicone rubber composition of the CIDR so that when the treatment is completed and the device is removed it can be disposed of in an environmentally friendly way. Research showed that biodegradable polymers typified by poly (ε-caprolactone) and starch like saccharide could be moulded and inpreganted with an intra vaginally active agent such as progesteron.

Active Delivery Device

The Active Delivery Device, an electronically controlled intra vaginal device, was developed to provide arbitrary and complex drug delivery profiles. A wireless link allowed for monitoring of onboard sensors and for the device to respond to external remote control.

The electronics manufactured from off the shelf components occupies 16 mL of a Theratron syringe. A microcontroller reads and logs sensor data and controls a gascell. The generated gas pressure propels the syringe piston and releases the formulation. A two-way radio link allows communication between other devices or a base station. Experiments confirmed variable-rate, arbitrary profile drug delivery qualified by internal sensors can be achieved over several days of operation with an error in delivered volume of less than ±3 per cent or 5 mL and that the device and delivery profile can be controlled via its two-way radio link. Another study showed that the device was able to respond to external sensor data indicating oestrus (body temperature loggers, pedometers) and change its delivery profile accordingly.