Advanced and controlled drug delivery systems in clinical disease management

Abstract

Advanced and controlled drug delivery systems are important for clinical disease management. In this review the most important new systems which have reached clinical application are highlighted. Microbiologically controlled drug delivery is important for gastrointestinal diseases like ulcerative colitis and distally localized Crohn's disease. In cardiology the more classic controlled release systems have improved patient compliance and decreased side effects. In the treatment of intractable pain the spinal and transdermal route is well documented. In neurology the flattened peak-through levels of antiepileptic drugs and anti Parkinson's drugs represents a more predictable kinetic profile. Tracheal delivery of corticosteroids and sympaticomimetics in asthma and Chronic Obstructive Pulmonary Disease is fully accepted in clinical practice: delivery by this route results in better efficacy and a better safety profile. In gynaecology the delivery of pulsatile hormones (LHRH) is used for pregnancy induction, while transdermal oestrogens are promising in the prevention of osteoporosis. In surgical practice the use of antibiotic impregnated bone cement and antibiotic impregnated biodegradable collagens is well established. To prevent infections intravascular catheters coated with heparin or antibiotics are used. In ophthalmology the Ocusert systems provide a controlled release of different drugs in the eye. Most spectacular is the clinical introduction of the first liposomal drugs; amfotericine B and daunorubicine. Liposomal formulations of these drugs have enhanced activity and decreased toxicity compared to conventional formulations.

Mechanisms of monoclonal antibody stabilization and release from silk biomaterials

“…The most obvious advantage is the potential for improved efficacy, by maintaining drug levels within the therapeutic window for longer periods of time [1]. Also, delivering drugs directly to the disease site eliminates the dependence on physiological targeting mechanisms and provides higher levels of therapeutic available at the targeted site [2,3]. Monoclonal antibodies are excellent therapeutic targets due to their specificity, modular structure, ability to leverage the patient’s own immune system, and ability to deliver a toxic payload [4-6].…”

In vitro and in vivo evaluations of biodegradable implants for hormone replacement therapy: Effect of system design and PK-PD relationship

“…A similar correlation and relationship were observed for implant II but not for implant I (possibly due to early termination of the animal study). The primary objective of applying subcutaneous implantation for drug delivery is to control the delivery of drug to subcutaneous tissue and to maintain the therapeutic effect throughout the treatment duration of interest [ 1,2]. Implant I appeared to best achieve these goals.…”

“…In vitro release kinetics of EE 2 and in vivo pharmacokinetics/pharmacodynamics in ovariectomized New Zealand White rabbits were carried out to study 3 implant prototypes: implant I (single-channel EE 2 distribution in polycaprolactone polymer core), implant II (homogeneous EE 2 distribution in polycaprolactone polymer matrix), and implant III (concentration-gradient EE 2 distribution in polycaprolactone and poly(dl-lactide-co-glycolide) (50:50 matrix). EE 2 was found to be released from all the implants in a nonlinear pattern with an order of implant III > implant II > implant I.…”

“…Subcutaneous implants have been increasingly recognized as a useful drug delivery system that provides greater assurance of patient compliance and a better therapeutic outcome than conventional drug therapies, particularly for chronic medication [1][2][3]. A survey of the literature showed that numerous studies have been performed to investigate the use of polymercontrolled drug delivery systems [4][5][6][7], efficacy [8][9][10], and pharmacokinetics and pharmacodynamics [11][12][13] of subdermal implants for the controlled delivery of drugs for long-term therapy.…”

Controlled release of an optically active compound by hydrogels of acrylic acid and its online detection

“…In this field, hydrogels of acrylic acid are also functional for the release of substances such as piperacillin‐tazobactam, fluconazole, as well as lipase immobilization . It is worth mentioning that controlled drug release has advantages over conventional treatments, including reduction of the side effects and of the number of doses administered to the patients . A study of this kind of system usually starts with the determination of the transport properties of the guest substances through the hydrogel .…”