Preparation of a polymeric reservoir naltrexone delivery device: effect of PEG content of the PLA membrane on drug release

Abstract

Background: Naltrexone is an orally active opioid agonist that has the potential for use as a treatment option for opiate addiction. However, in order for the drug to be effective, sufficient blood levels must be maintained for 4 to 8 months, which typically requires selfadministration by the patient, resulting in complications. Aim: The aim of this study was to develop a polymeric reservoir device containing naltrexone. Materials & methods: The reservoir device was prepared using high-molecular-weight poly-L-lactide and the cylindrical device by dipping a stainless-steel rod in a methylene chloride solution of polylactic acid (PLA). High-molecular-weight PLA was used to take advantage of the low biodegradation rate of the polymer, in order to obtain constant drug release from the device based on the diffusion mechanism rather than biodegradation of the polymer. The impact of the polymeric device weight and polyethyleneglycol content of the polymeric membrane of the device on the release of naltrexone from the device was studied. Results: Rate of drug release from the reservoir device was shown to be successfully regulated by controlling the device weight as well as the amount of hydrophilic additive in the polymeric membrane of the device. The higher the amount of the hydrophilic content of the polymeric membrane, the faster the rate of drug release from the device. Conclusion: Prepared reservoir devices released their drug content through the use of a high-molecular-weight PLA. The presence of NaCl as an osmotic agent did not affect the release profile of naltrexone -an indicator that diffusion is the mechanism of release of naltrexone from the PLA reservoir system.

Preparation and analysis of a sustained drug delivery system by PLGA–PEG–PLGA triblock copolymers

“…Because of the poor compliance of the addicted patients that regularly use naltrexone hydrochloride, the development of novel extended-release systems that can provide an effective drug concentration in the blood for a long time after just one injection is desirable [16][17][18].…”