Injectable Sustained Release Drug Delivery
Sustained release drug delivery systems (SRDDSs) have greatly improved the treatment of various disorders, partly by improving patient compliance as adherence to various medical treatments has been shown to be inversely related to dosing frequency. Therapeutic ratios of existing drugs also can be improved through localized administration, which reduces their toxicity to nontarget organs and helps overcome unfavorable pharmacokinetic properties. Development of SRDDSs using FDA-approved drugs is far less resource-intensive than developing a new pharmaceutical entity, which costs $800 million on average.
The injectable SRDDS is based on subcutaneous and/or intramuscular injection of microparticle-based drug formulations. Biocompatible and biodegradable polymers are used to obtain the desired, linear release kinetics of the drug from its depot. Active programs currently are addressing important medical needs ranging from mental health to infectious diseases. Several of these projects are moving into clinical trials.