Table 1. Influential factors and obtained experimental responses for different formulations.

Test	Terpene type	Terpene Conc. (%)	Method	Size (µm)	Bupivacaine (EE)%	Bupivacaine (LE)%	Buprenorphine (EE)%	Buprenorphine (LE)%
1	Nerolidol	2.0	Ethanol injection	0.39 ± 0.32	94.19 ± 0.52	18.8 ± 0.24	98.77 ± 2.03	19.75 ± 0.81
2	Nerolidol	2.0	Thin layer	5.22 ± 0.22	91.07 ± 1.20	18.2 ± 0.75	94.96 ± 1.64	18.9 ± 0.39
3	Menthol	2.0	Ethanol injection	0.99 ± 0.18	92.14 ± 0.45	18.4 ± 0.19	97.53 ± 1.43	19.5 ± 0.96
4	Menthol	2.0	Thin layer	4.86 ± 0.30	24.36 ± 0.89	4.8 ± 0.72	96.95 ± 0.98	19.3 ± 0.72
5	Mix	2.0	Ethanol injection	0.92 ± 0.27	79.73 ± 0.68	15.9 ± 0.3	92.40 ± 0.85	18.4 ± 0.8
6	Mix	2.0	Thin layer	5.01 ± 0.56	73.90 ± 0.67	14.7 ± 0.45	88.40 ± 0.74	17.6 ± 0.41
7	Nerolidol	1.0	Ethanol injection	1.13 ± 0.48	95.18 ± 2.65	19.03 ± 1.77	97.73 ± 0.43	19.5 ± 0.39
8	Nerolidol	1.0	Thin layer	5.73 ± 0.19	82.95 ± 0.94	16.5 ± 0.4	92.55 ± 0.56	18.5 ± 0.31
9	Menthol	1.0	Ethanol injection	1.34 ± 0.45	83.10 ± 0.82	16.6 ± 0.65	91.64 ± 0.34	18.3 ± 0.4
10	Menthol	1.0	Thin layer	5.60 ± 0.31	58.95 ± 0.78	11.7 ± 0.55	92.49 ± 2.03	18.4 ± 1.21
11	Mix	1.0	Ethanol injection	1.46 ± 0.27	78.66 ± 1.01	15.7 ± 0.89	88.92 ± 1.84	17.7 ± 0.5
12	Mix	1.0	Thin layer	4.07 ± 0.37	77.39 ± 2.04	15.4 ± 1.03	90.24 ± 0.64	18.04 ± 0.37
13	Nerolidol	0.5	Ethanol injection	0.65 ± 0.51	87.06 ± 0.69	17.4 ± 0.22	95.67 ± 0.24	19.1 ± 0.21
14	Nerolidol	0.5	Thin layer	4.56 ± 0.29	77.70 ± 0.83	15.5 ± 0.64	90.60 ± 0.15	18.1 ± 0.1
15	Menthol	0.5	Ethanol injection	0.88 ± 0.38	93.64 ± 0.93	18.7 ± 0.51	98.04 ± 0.18	19.6 ± 0.13
16	Menthol	0.5	Thin layer	5.86 ± 0.26	43.97 ± 1.57	8.7 ± 0.9	83.53 ± 0.21	16.7 ± 0.17
17	Mix	0.5	Ethanol injection	0.83 ± 0.25	88.88 ± 3.01	17.7 ± 1.89	95.83 ± 3.60	19.16 ± 2.23
18	Mix	0.5	Thin layer	5.67 ± 0.51	63.38 ± 1.45	12.6 ± 0.87	86.46 ± 0.63	17.2 ± 0.51