Mitigation of experimental, chronic post-thoracotomy pain by preoperative infiltration of local slow-release bupivacaine microspheres.

Background: Postoperative pain is treated incompletely and ineffectively in many circumstances, and chronic postoperative pain causes suffering and diminishes productivity. The objective of this project is to determine whether a recently developed slow-release formulation of bupivacaine was effective in reducing the experimental chronic postoperative pain.

Methods: In male Sprague-Dawley rats (250-300 g body weight), bupivacaine-releasing microspheres (MS-Bupi), containing 60 mg of bupivacaine base, were locally injected (MS-Bupi-L) 2 hours preoperatively into the subcutaneous compartment at the locus for experimental thoracotomy.

Local pathology and systemic serum bupivacaine after subcutaneous delivery of slow-releasing bupivacaine microspheres.

Background: Prolonged local anesthesia, particularly desirable to minimize acute and chronic postoperative pain, has been provided by microspheres that slowly release bupivacaine (MS-Bup). In this study, we report on the systemic drug concentrations and the local dermatopathology that occur after subcutaneous injection of MS-Bup.

Methods: Rats (approximately 300 g) were injected under the dorsolumbar skin with MS-Bup containing 40 mg of bupivacaine (base) or with 0.

Prolonged amelioration of experimental postoperative pain by bupivacaine released from microsphere-coated hernia mesh.

Background And Objectives: Postoperative pain alters physiological functions and delays discharge. Perioperative local anesthetics are effective analgesics in the immediate 1- to 2-day postoperative period, but acute pain often lasts longer. The goal of this work was to develop a local anesthetic formulation adhering to an intraoperative implanted device that reduces pain for at least 3 days after surgery.

Inhibition by local bupivacaine-releasing microspheres of acute postoperative pain from hairy skin incision.

Background: Acute postoperative pain causes physiological deficits and slows recovery. Reduction of such pain by local anesthetics that are delivered for several days postoperatively is a desirable clinical objective, which is approached by a new formulation and applied in animal studies reported here.

Methods: We subcutaneously injected a new formulation of poly-lactic-co-glycolic acid polymer microspheres, which provides steady drug release for 96+ hours into rats at the dorsal region 2 hours before surgery.

Prolonged nerve block by microencapsulated bupivacaine prevents acute postoperative pain in rats.

Background And Objectives: To minimize acute postoperative pain, a new formulation of slowly released bupivacaine was developed.

Methods: Bupivacaine was microencapsulated at 60% (wt/wt) in poly-lactide-co-glycolide polymers and characterized for physicochemical properties and bupivacaine release kinetics. This formulation was injected around the rat sciatic nerve to produce an antinociceptive effect to toe pinch.

Testosterone release from a subcutaneous, biodegradable microcapsule formulation (Viatrel) in hypogonadal men.

Men with hypogonadism require testosterone replacement for optimal health. In the United States, testosterone is currently administered by daily transdermal patches, topical gels or intramuscular injections every 1-3 weeks. Biodegradable polylactide-co-glycolide microcapsules are currently used for long-term drug delivery in humans.