Abstract
Local anesthetics are commonly used for pain relief by regional nerve blocking. In this study, we fabricated solvent-free biodegradable pellets to extend the duration of lidocaine release without any significant local or systemic toxicity levels. To manufacture the pellets, poly[(d,l)-lactide-co-glycolide] (PLGA) was first pre-mixed with lidocaine powder into different ratios. The powder mixture was then compressed with a mold (diameter of 1, 5, 8 or 10 mm) and sintered at 65 °C to form pellets. The in vitro release study showed that the lidocaine/PLGA pellets exhibited a tri-phase release behavior (a burst, a diffusion-controlled release and a degradation-dominated release) and reached completion around day 28. Scanning electron microscope (SEM) photos show that small channels could be found on the surfaces of the pellets on day 2. Furthermore, the polymer matrix swelled and fell apart on day 7, while the pellets became viscous after 10 days of in vitro elution. Perineural administration of the lidocaine/PLGA pellets produced anti-hypersensitivity effects lasting for at least 24 h in rats, significant when compared to the control group (a pure PLGA was pellet administered). In addition, no inflammation was detected within the nerve and in the neighboring muscle by histopathology.
Highlights
Acute pain relief is an important issue for post-operative management
Most local anesthetics bind to sodium channels in the nerve membrane, preventing channel activation and the large transient sodium influx associated with membrane depolarization
In order to prolong the period of drug release, a catheter is usually deployed in the epidural space or at the peripheral nerves for continuous infusion
Summary
Acute pain relief is an important issue for post-operative management. Neuronal block with local anesthetics is one of the most effective methods to provide dynamic pain relief after major surgical procedures. In order to prolong the period of drug release, a catheter is usually deployed in the epidural space or at the peripheral nerves for continuous infusion. The continuous infusion of local anesthetics may cause complications, such as infection, catheter misplacement or systemic toxicity [4]. An ideal drug delivery system for local anesthetic should: (1) achieve an adequate drug concentration at the target site; (2) provide a slow and constant release of the drug over a prolonged period; and (3) be biodegradable, so that a second operation to remove the delivery vehicle is not necessary [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
