This study aimed to evaluate the preliminary safety of self-developed meloxicam (MEL) oil suspension and determine the comparative pharmacokinetics of it at 0.8 and 2 mg/kg body weight (b.w.) dosages in pigs following a single intramuscular administration. Six rabbits were used for the study of preliminary safety and six healthy pigs were used for pharmacokinetics study by a crossover design in two periods. The muscle irritation results showed that both of the MEL oil suspension and the conventional injection had no significant changes at the dosage of 0.4 mg/kg b.w.. However, at the dosage of 2 mg/kg b.w., both of the self-developed MEL oil suspension and the MEL conventional injection showed mild irritation to muscle. Plasma concentrations of MEL were measured by ultra performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). The MEL plasma concentrations were quantified up to 30 h and 72 h after intramuscular administration at the low- and high-dosage, respectively. The difference was statistically significant (P < 0.05) between different dosages in pharmacokinetic parameters of t_1/2λz, C_max, AUC_0-t, AUC_0-μ, MRT, and V_d. The C_max values of MEL were 1.92 ± 0.34 μg/ml and 3.03 ± 1.25 μg/ml at dosages of 0.8 and 2 mg/kg b.w. while the t_max values were 3.25 ± 1.04 h and 4.00 ± 1.26 h, respectively. The pharmacokinetics results of self-developed MEL oil suspension demonstrated that the retention time of it in pigs was prolonged, showing the sustained-release effect. Therefore, Oil suspension was an ideal new drug loading form of MEL.

本研究旨在评估自主研发的美洛昔康（MEL）油混悬液的初步安全性，并确定其在0.8和2时的比较药代动力学。 单次肌肉注射后，猪的 mg/kg 体重 (bw) 剂量。六只兔子用于初步安全性研究，六只健康猪用于通过两个时期的交叉设计进行药代动力学研究。肌肉刺激结果表明，在 0.4 mg/kg bw 的剂量下，MEL 油悬浮液和常规注射液均无显着变化。然而，在 2 mg/kg bw 的剂量下，自主研发的 MEL 油悬浮液和 MEL 常规注射剂均对肌肉表现出轻微刺激。通过超高效液相色谱-串联质谱法 (UPLC-MS/MS) 测量 MEL 的血浆浓度。分别以低剂量和高剂量肌肉注射后 30 小时和 72 小时对 MEL 血浆浓度进行量化。P  < 0.05) 不同剂量之间的 t _1/2λz、C _max、AUC _0-t、AUC _0-μ、MRT 和 V _{d 的}药代动力学参数。在 0.8 和 2 毫克/千克体重的剂量下，MEL的 C_最大值分别为 1.92 ± 0.34 微克/毫升和 3.03 ± 1.25 微克/毫升，而 t_最大值分别为 3.25 ± 1.04 小时和 4.00 ± 1.26 小时。自主研发的MEL油混悬液的药代动力学结果表明，其在猪体内的滞留时间延长，显示出缓释作用。因此，油混悬液是一种理想的MEL新型载药形式。