Implantable insulin controlled release

Implantable Insulin Controlled Release Systems for Treating Diabetes Mellitus... 

Surini S, Akiyama H, Morishita M, Nagai T, Takayama K. Release phenomena of insulin from an implantable device composed of a polyion complex of chitosan and sodium hyaluronate. J Controlled Release 2003 90 291-301. 

The integration of biosensors with drag delivery systems allows the controlled release of a drag substance in response to the levels of biological modulator. For example, the use of a glucose biosensor may be used to control the release of insulin from an implanted device or perhaps even an iontophoretic delivery device (see Chapter 8). 

Miyazaki S, Yokouchi C, and Takada M. External control of drug release Controlled release of insulin from a hydrophilic pol3nner implant by ultrasound irradiation in diabetic rats. J. Pharm. Pharmacol. 1988 40 716-717. 

As a result of the shortcomings of current insulin therapy, much work has been directed toward developing polymeric controlled release systems that can be implanted or injected into the body to achieve glucose control in patients with diabetes. This chapter will review the history of such systems and will discuss ciurent technology and future trends for the sustained delivery of insulin for the treatment of diabetes mellitus. Several media serving as carriers include synthetic absorbable polymers, biomolecules, and ceramics. 

There have been significant advances with regards to implantable delivery systems for the controlled release of insulin. Many of the systems previously studied have characteristics considered favorable, but no one system possesses all of the necessary attributes to make such systems a reality in humans. It is clear that biocompatibility and biodegradability are vital components to the ideal delivery system. Such systems do not require surgical removal upon exhaustion of drug and are seamlessly integrated into the... 

Other Formulations. Neural networks have been applied to the modeling of pellet formulations to control the release of theophylline [63] and to control the rate of degradation of omeprazole [64]. They have also been applied to the preparation of acrylic microspheres [65] and to model the release of insulin from an implant [66]. In arecent study from Brazil, the release of hydrocortisone from a biodegradable matrix has been successfully modeled [67]. 

In addition to needles and syo inges, alternative techniques for insulin administration have been developed, some availing themselves of the kinetics of insulin insulin pens (supplied preloaded or with replaceable cartridges), external infusions and implantable pumps. These latter are convenient for cm accurately controlled continuously functioning biofeedback system, but pose difficulties for routine replacement in insulin deficiency. Therefore sustained-release (depot) formulations are used to provide an approach reasonably near to natural function and compatible with the convenience of daily living. An even closer approach is provided by the development of (at present inevitably expensive) miniaturised infusion pumps which can be used by reliable patients. 

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