Development and characterization of PLGA-Bupivacaine and PLGA-S75: R25 Bupivacaine (Novabupi®) biodegradable implants for postoperative pain

Abstract In the hospital environment, postoperative pain is a common occurrence that impairs patient recovery and rehabilitation and lengthens hospitalization time. Racemic bupivacaine hydrochloride (CBV) and Novabupi® (NBV) (S (-) 75% R (+) 25% bupivacaine hydrochloride) are two examples of local anesthetics used in pain management, the latter being an alternative with less deleterious effects. In the present study, biodegradable implants were developed using Poly(L-lactide-co-glycolide) through a hot molding technique, evaluating their physicochemical properties and their in vitro drug release. Different proportions of drugs and polymer were tested, and the proportion of 25%:75% was the most stable for molding the implants. Thermal and spectrometric analyses were performed, and they revealed no unwanted chemical interactions between drugs and polymer. They also confirmed that heating and freeze-drying used for manufacturing did not interfere with stability. The in vitro release results revealed drugs sustained release, reaching 64% for NBV-PLGA and 52% for CBV-PLGA up to 30 days. The drug release mechanism was confirmed by microscopy, which involved pores formation and polymeric erosion, visualized in the first 72 h of the in vitro release test. These findings suggest that the developed implants are interesting alternatives to control postoperative pain efficiently.

Biodegradable Implants in Orthopaedics.

Bioabsorbable materials are more commonly used now days in orthopaedic surgeries. Bioabsorbable implants for fracture fixation, and meniscal repair. These implants provide the advantages of gradual load transfer to the healing tissue, reduced need for implant removal, and radiolucency, which facilitates postoperative radiographic evaluation and no hinderance in second surgery. These also carries disadvantages like, more expensive, having less strength than metals, tissue reactions including mild fluid accumulation, painful erythematous fluctuating papule, sterile sinus tract formation, osteolysis, synovitis, and hypertrophic fibrous encapsulation. We advocate more researches to be carried out for the best suitability of these materials in orthopaedic surgeries.

Tip Plasty using Biodegradable Plate as a Columella Strut

PURPOSE: Most surgeons have used autogenous cartilage for columella strut graft. But the supply of autogenous cartilage is often limited. So, this study is to investigate the usefulness of biodegradable plate as columella strut material. METHODS: We studied 19 patients who have secondary cleft nasal deformity. Patients were divided into two groups. Group A patients who were not closed their growth plate underwent columella strut graft only with biodegradable plate through endonasal approach. The biodegradable plate was inserted between nasal tip and anterior nasal spine. Group B patients were closed their growth plate. They had an operation for columella strut graft with biodegradable plate fixed with autogenous conchal cartilage. If nasal tip projection was insufficient, we performed additionally onlay graft on nasal tip with autogenous soft tissue or remnant cartilage. RESULTS: As a result of mean 14 months follow-up, we achieved a good nasal tip projection, narrowing of interalar distance and symmetrical nostril shape. No specific complications were reported except 2 cases, which were the extrusion of biodegradable plate into the nasal cavity and Staphylococcus aureus infection. CONCLUSION: The columella strut graft using biodegradable plate is simple and effective method. Biodegradable plate can be a good substitute for columella strut in patients who can not use autogenous cartilages.

Preparation and in Vitro Release of Risperidone Injectable Biodegradable Implants / 中国药房

OBJECTIVE:To prepare risperidone injectable biodegradable implants and study its in vitro release. METHODS: Polylactide-co-glycolide copolymer(PLGA)was chosen for carrier and N-Methyl pyrolidone(NMP)as solvent to prepare risperidone injectable biodegradable implants. The percentage of accumulative drug release within 30 days,the change in molecular weight of copolymer and superficial opening diameters of copolymer in function time were observed. RESULTS:Drug release curve of risperidone injectable biodegradable implants for 30 days was stable with small burst. The percentage of accumulative drug release was 89.01% and the percentage of burst accounted for 13.8% at the first 24 hours. The average molecular weight of copolymer decreased to about 10 000 from 43 000 after 30 days and the size of the superficial openings became larger and larger. CONCLUSION:Risperidone injectable biodegradable implants can release continuously and stably in vitro for 30 days.