BZM是紋狀體多巴胺D2/D3受體(D2R) SPECT造影劑[123I]IBZM(碘苯醯胺,iodobenzamide)的前驅物與自由態螯合基。本研究利用逆相高效液相層析儀(RP-HPLC),進行BZM純度分析方法開發與方法確效實驗。層析條件包括Zorbax eclipse XDB-C18管柱;10 mM醋酸銨緩衝溶液(pH 7.0)與乙腈混合梯度流洗液;0.5 mL/min流速與254 nm UV偵測波長。本方法在分析0.5-5.5μg樣品線性範圍時可得大於0.9997之相關係數。BZM主要不純物(impurity A, t(下标 R)-3.85 min)含量的最低偵測下限(LOD)與最低定量下限(LOQ)分別是0.028%與0.094%。從方法確效實驗,包括分析專一性、精密度、準確度、線性範圍、LOD/LOQ、耐變性與溶液穩定性等指標參數之評估結果,顯示本方法是一種穩定的藥物品質管制分析方法。此外,本研究也探討與發現BZM 及非放射性IBZM的最佳前驅離子-子離子轉移離子對,分別是m/z 279.0-112.0與m/z 405.0-112.0。從所推測之BZM與IBZM碎裂離子與碎裂路徑,顯示利用MRM技術,測定[123I]IBZM造影劑靜脈注射針劑中自由態BZM螯合基與[123I]IBZM含量的可行性。
We developed and validated a reverse-phase high performance liquid chromatography (RP-HPLC) method for the purity assay of BZM. BZM is a precursor and free ligand of [123I] IBZM (iodobenzamide) that is a SPECT imaging agent for striatal dopaminergic D2/D3 receptor (D2R). The chromatographic separation was achieved on a Zorbax Eclipse XDB-C18 column with a gradient mobile phase consisting of 10 mM ammonium acetate buffer, pH 7.0 and acetonitrile at a flow rate of 0.5 mL/min. The absorbance at 254 nm against the concentration of BZM over the range 0.5-5.5 μg was linear, with a correlation coefficient above 0.9997. The limit of detection (LOD) and quantification (LOQ) of major impurity (impurity A, tR = 3.85 min) in BZM were 0.028% and 0.094%, respectively. Method validation parameters, including specificity, precision, accuracy, linearity, LOD/LOQ, robustness and solution stability were evaluated, indicating the potential of this method in pharmaceutical quality control. Moreover, the most sensitive precursor to product ion transitions for the identification of BZM and 'cold' IBZM by LC-ESI-MS/MS were found to be m/z 279.0-112.0 and 405.0-112.0, respectively. The present results allow identification of fragmentation ions and proposition of the pathways of BZM and ‘cold’ IBZM, showing that the feasibility of this method for quantification of free ligand BZM in SPECT imaging agent [123I] IBZM injection.