Department of Pharmaceutical Sciences, University of Michigan, 428 Church St., Ann Arbor, MI, USA.
Pharm Res. 2010 Apr;27(4):628-43. doi: 10.1007/s11095-009-0038-5. Epub 2010 Feb 11.
The objective of this study was to formulate and evaluate freeze-dried black raspberry (FBR) ethanol extract (RE) loaded poly(DL-lactic-co-glycolic acid) (PLGA) and poly(DL-lactic acid) (PLA) injectable millicylindrical implants for sustained delivery of chemopreventive FBR anthocyanins (cyanidin-3-sambubioside (CS), cyanidin-3-glucoside (CG) and cyanidin-3-rutinoside (CR)).
Identification and quantitation of CS, CG, and CR in RE was performed by mass spectroscopy and HPLC. RE:triacetyl-beta-cyclodextrin (TA-beta-CD) inclusion complex (IC) was prepared by a kneading method and characterized by X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR) and UV-visible spectroscopy. RE or RE:TA-beta-CD IC-loaded PLGA or PLA implants were prepared by a solvent extrusion method. In vitro and in vivo controlled release studies were conducted in phosphate-buffered saline Tween-80 (pH 7.4, 37 degrees C) and after subcutaneous administration in male Sprague-Dawley rats, respectively. Anthocyanins were quantified by HPLC at 520 nm.
The content of CS, CG, and CR in RE was 0.2, 1.5, and 3.5 wt%, respectively. The chemical stability of anthocyanins in solution was determined to be pH-dependent, and their degradation rate increased with an increase in pH from 2.4 to 7.4. PLGA/PLA millicylindrical implants loaded with 5 or 10 wt% RE exhibited a high initial burst and short release duration of anthocyanins (35-52 and 80-100% CG + CR release after 1 and 14 days, respectively). The cause for rapid anthocyanins release was linked to higher polymer water uptake and porosity associated with the high osmolytic components of large non-anthocyanin fraction of RE. XRD, (1)H NMR and UV-visible spectroscopy indicated that the non-anthocyanin fraction molecules of RE formed an IC with TA-beta-CD, decreasing the hydrophilicity of RE. Formation of an IC with hydrophobic carrier, TA-beta-CD, provided better in vitro/in vivo sustained release of FBR anthocyanins (16-24 and 97-99% CG + CR release, respectively, after 1 and 28 days from 20 wt% RE:TA-beta-CD IC/PLA implants) over 1 month, owing to reduced polymer water uptake and porosity.
PLA injectable millicylindrical implants loaded with RE:TA-beta-CD IC are optimal dosage forms for 1-month slow and continuous delivery of chemopreventive FBR anthocyanins.
本研究的目的是制备和评价负载黑覆盆子（BR）乙醇提取物（RE）的聚（DL-丙交酯-共-乙交酯）（PLGA）和聚（DL-乳酸）（PLA）可注射微圆柱型植入物，用于持续输送化学预防用 BR 花色苷（矢车菊素-3-桑布双糖苷（CS）、矢车菊素-3-葡萄糖苷（CG）和矢车菊素-3-鼠李糖苷（CR））。
通过质谱和 HPLC 鉴定和定量 RE 中的 CS、CG 和 CR。RE：三乙酰基-β-环糊精（TA-β-CD）包合物（IC）通过捏合法制备，并通过 X 射线衍射（XRD）、核磁共振波谱（NMR）和紫外可见光谱进行表征。通过溶剂挤出法制备 RE 或 RE：TA-β-CD IC 负载的 PLGA 或 PLA 植入物。在磷酸盐缓冲盐水吐温-80（pH 7.4，37°C）中和皮下给药后，分别在体外和体内进行控释研究。在 520nm 处通过 HPLC 定量花色苷。
RE 中 CS、CG 和 CR 的含量分别为 0.2wt%、1.5wt%和 3.5wt%。花色苷在溶液中的化学稳定性取决于 pH 值，随着 pH 值从 2.4 增加到 7.4，其降解速度增加。负载 5wt%或 10wt%RE 的 PLGA/PLA 微圆柱植入物表现出较高的初始突释和较短的花色苷释放时间（1 天和 14 天后分别为 35-52%和 80-100%CG+CR 释放）。花色苷快速释放的原因与聚合物的高吸水性和与 RE 中非花色苷部分的大亲水性成分相关的高渗透压有关。XRD、（1）H NMR 和紫外可见光谱表明，RE 的非花色苷部分分子与 TA-β-CD 形成 IC，降低了 RE 的亲水性。与疏水性载体 TA-β-CD 形成 IC 可提供更好的体外/体内持续释放 BR 花色苷（20wt%RE：TA-β-CD IC/PLA 植入物后 1 天和 28 天分别释放 16-24%和 97-99%CG+CR），持续 1 个月，这是由于聚合物的吸水性和孔隙率降低。
负载 RE：TA-β-CD IC 的 PLA 可注射微圆柱型植入物是 1 个月内缓慢持续输送化学预防用 BR 花色苷的最佳剂型。
