In:
Current Drug Delivery, Bentham Science Publishers Ltd., Vol. 16, No. 6 ( 2019-08-27), p. 490-499
Abstract:
The local anesthetic drugs, especially ropivacaine, were considered favorable
analgesia for postoperative management because of their effective local pain relief and low adverse effects. However, the short half-life and the resulting in bolus doses lead to the indistinctive improvement
of these drugs in postoperative pain relief. Therefore, the ropivacaine microspheres with sustained release and low initial burst release were anticipated. Methods: Three methods including oil in water (O/W), water in oil in water (W/O/W), and solid in oil in
water (S/O/W) emulsion solvent evaporation method were used to optimize the ropivacaine loaded PLGA microspheres. The microspheres were evaluated both in vitro and in rats. The in vitro-in vivo
correlation (IVIVC) was also investigated. Results: The microspheres prepared by O/W method showed more satisfactory properties and the microspheres
used for evaluation were prepared by O/W method. The particle size, drug loading, encapsulation efficiency and burst release were 11.19±1.24 µm, 28.37±1.15%, 98.15±3.98%, and 10.96±5.37% for
microspheres with PLGA of 12 kDa, and 6.64±0.61 μm, 19.62±0.89%, 92.74±4.21%, and 18.42±5.12% for microspheres with PLGA of 8 kDa, respectively. These microspheres were also injected into rats by
subcutaneous, intramuscular and intraperitoneal route, respectively. It was indicated that the detectable concentration of ropivacaine could last for at least 20 days for both kinds of microspheres in spite of injection routes. The low burst releases at 1 d were also manifested in rats and they were 6.62%, 6.99%,
6.48% for the microspheres with PLGA of 12 kDa, and 4.72%, 4.33%, 4.48% for the microspheres with PLGA of 8 kDa by intraperitoneal, intramuscular and subcutaneous route, respectively. A linear relationship
between the in vitro release and the in vivo adsorption of ropivacaine from microspheres was also established. Conclusion: The ropivacaine microspheres with sustained release and low burst release were acquired,
which indicated that the postoperative pain relief might last longer and the side effects might get lower. Therefore, the ropivacaine microspheres prepared in this paper have great potential for clinical use.
Type of Medium:
Online Resource
ISSN:
1567-2018
DOI:
10.2174/1567201816666190528122137
Language:
English
Publisher:
Bentham Science Publishers Ltd.
Publication Date:
2019
SSG:
15,3
Permalink