Table 3. In Vivo Efficacies of Five Generics and the Innovator Product of Vancomycin.

Product	R2	Emax (log10 CFU/g)	p value	Slope (N)	p value	ED50 (mg/kg/day)	p value	BD (mg/kg/day)	p value	1LKD (mg/kg/day)	p value	p value (CFA) (IP vs. GP)
S. aureus ATCC 29213 104 inoculum, PDP±SE
Vancocin CP	0.995	−9.33±0.27	Reference	0.69±0.36	Reference	1.22±1.61	Reference	6.39±0.97	Reference	19.97±5.30	Reference	Reference
Generic A	0.996	IVP	-	IVP	-	IVP	-	IVP	-	IVP	-	-
Generic B	0.992	−9.34±0.35	0.994	0.69±0.43	0.984	1.53±2.15	0.885	7.80±1.17	0.037*	23.95±6.26	0.637	0.786
Generic C	0.995	−9.22±0.13	0.481	1.15±0.39	0.228	4.32±2.37	0.156	12.07±1.13	0.003*	24.59±4.19	0.509	0.599
Generic D	0.995	−9.18±0.26	0.672	0.71±0.41	0.968	1.19±1.76	0.983	6.58±1.04	0.897	22.63±6.79	0.764	0.405
Generic E	0.994	−9.27±0.17	0.743	1.04±0.33	0.279	4.59±2.24	0.091	14.02±1.43	0.001*	30.17±5.45	0.209	0.050*
S. aureus ATCC 29213 108 inoculum, PDP±SE
Vancocin CP	0.989	−16.34±0.57	Reference	0.86±0.22	Reference	8.36±1.83	Reference	20.46±1.42	Reference	29.17±2.31	Reference	Reference
Generic A	0.986	−16.44±0.62	0.855	0.87±0.23	0.945	9.26±1.89	0.619	21.84±1.47	0.513	30.80±2.36	0.632	0.952
Generic B	0.989	−16.61±0.65	0.606	0.79±0.18	0.718	10.12±1.46	0.216	24.83±1.79	0.084	35.78±2.9	0.105	0.156
Generic C	0.991	−16.25±0.51	0.862	0.86±0.19	0.966	8.91±1.59	0.719	22.09±1.54	0.452	31.58±2.53	0.498	0.779
Generic D	0.991	−16.52±0.59	0.707	0.81±0.18	0.757	9.32±1.46	0.489	23.10±1.66	0.254	33.32±2.72	0.271	0.493
Generic E	0.991	−16.95±0.87	0.353	0.67±0.16	0.222	9.19±1.26	0.504	24.52±2.02	0.131	37.17±3.41	0.081	0.029*
S. aureus Mu3 104 inoculum, PDP±SE
Vancocin CP	0.950	−9.71±2.59	Reference	0.41±1.40	Reference	0.19±2.23	Reference	3.29±1.34	Reference	29.32±16.62	Reference	Reference
Generic A	0.931	−9.58±1.77	0.952	0.56±1.11	0.899	1,22±5.28	0.749	10.48±3.47	0.082	59.01±29.82	0.404	0.653
Generic B	0.958	−9.29±0.53	0.624	0.93±0.76	0.476	4.48±5.44	0.180	18.03±4.14	0.006*	69.31±31.47	0.287	0.162
Generic C	0.940	−9.18±0.55	0.642	1.01±1.25	0.608	3.77±7.96	0.512	14.23±3.14	0.009*	63.21±31.99	0.369	0.559
Generic D	0.966	−10.65±7.47	0.806	0.24±0.79	0.831	0.16±0.72	0.972	5.75±2.85	0.453	60.59±34.47	0.432	0.614
Generic E	0.947	−9.36±1.07	0.846	0.66±1.28	0.850	1.13±5.53	0.810	8.08±2.48	0.121	50.62±27.32	0.520	0.859
S. aureus Mu3 108 inoculum, PDP±SE
Vancocin CP	0.994	−17.77±0.78	Reference	0.66±0.11	Reference	12.38±1.09	Reference	24.14±1.35	Reference	34.99±2.09	Reference	Reference
Generic A	0.995	−19.89±2.27	0.148	0.41±0.11	0.021*	15.15±6.97	0.546	23.14±1.77	0.661	38.05±3.01	0.424	0.004*
Generic B	0.991	−19.02±1.87	0.346	0.49±0.13	0.190	13.71±3.94	0.646	23.88±1.61	0.903	37.14±2.62	0.537	0.290
Generic C	0.993	−18.29±1.37	0.647	0.52±0.12	0.222	12.05±2.24	0.884	24.47±1.66	0.883	38.27±2.76	0.367	0.016*
Generic D	0.995	−19.70±2.01	0.146	0.43±0.09	0.017*	15.43±6.14	0.425	24.47±1.84	0.889	39.93±3.11	0.218	0.001*
Generic E	-	IVP	-	IVP	-	IVP	-	IVP	-	IVP	-

CFU, colony-forming units; PDP, pharmacodynamic parameters; SE, standard error; E_max, maximum effect; ED₅₀, effective dose to kill 50% of E_max; BD, bacteriostatic dose; 1LKD, one-log kill dose; IVP, invalid parameter: it was not possible input into Hill's equation or the nonlinear regression failed any of the presumptions of normality and homoscedasticity; IP, innovator product; GP, generic product; CFA, curve fitting analysis.

^*Statistically significant (p<0.05).