A Recent Update on Drug Delivery Systems for Pain Management

Emerging Advances in Nanocarriers Approaches in the Effective Therapy of Pain Related Disorders: Recent Evidence and Futuristic Needs

Pain disorders are the primary cause of disability nowadays. These disorders, such as rheumatoid arthritis (RA) and osteoarthritis (OA), cause loss of function, joint pain and inflammation and deteriorate the quality of life. The treatment of these inflammatory diseases includes anti-inflammatory drugs administered via intra-articular, topical or oral routes, physical rehabilitation or surgery. Owing to the various side effects these drugs could offer, the novel approaches and nanomaterials have shown potential to manage inflammatory diseases, prolonged half-life of anti-inflammatory drugs, reduced systemic toxicity, provide specific targeting, and refined their bioavailability. This review discusses in brief about the pain pathophysiology and its types. The review summarizes the conventional therapies used to treat pain disorders and the need for novel strategies to overcome the adverse effects of conventional therapies. The review describes the recent advancements in nanotherapeutics for inflammatory diseases using several lipids, polymers and other materials and their excellent efficiency in improving the treatment over conventional therapies. The results of the nanotherapeutic studies inferred that the necessity to use nanocarriers is due to their controlled release, targeting drug delivery to inflamed tissues, low toxicity and biocompatibility. Therefore, it is possible to assert that nanotechnology will emerge as a great tool for advancing the treatment of pain disorders in the near future.

The Influence of Diabetic Peripheral Neuropathy on the Duration of Sciatic Nerve Block with 1.3% Liposomal Bupivacaine and 0.25% Bupivacaine Hydrochloride in a Mouse Model

Little is known regarding the pharmacological properties of extended-release local anesthetics in the setting of diabetic peripheral neuropathy. We investigated and compared the duration of sciatic nerve block following administration of clinically relevant concentrations of liposomal bupivacaine (LB) and bupivacaine hydrochloride (BH) in diabetic mice with peripheral neuropathy. In this prospective, randomized, and double-blind study, twenty-four female C57BL/6J-OlaHsd mice were assigned to a streptozotocin-induced type 1 diabetes group and a control group without diabetes. The presence of peripheral neuropathy was established by assessing the duration of thermal latency of the plantar and tail-flick tests, following which both groups were subdivided into two subgroups in which 35 mg/kg of 1.31% LB and 7 mg/kg of 0.25% BH were respectively administered for sciatic nerve block. The average sensory block duration with BH was 106 min and 117.1 min in the control and diabetic groups, respectively. With LB, the average sensory block duration was 118 min in the control mice, while in mice with diabetic peripheral neuropathy, the average block duration was significantly longer and above the 270 min limit set in our study. Accordingly, sensory block duration was longer with LB compared to BH, and diabetic peripheral neuropathy significantly increased sciatic nerve block duration with LB.