On-spot quantification of modafinil in generic medicines purchased from the Internet using handheld Fourier transform-infrared, near-infrared and Raman spectroscopy

Journal of Analytical Science and Technology

Table 3 Results of the PLSR models constructed using the three techniques

Modelnumber	F	C:V ratio	r²calib	RMSEC (% m/m)	r² valid	RMSEP (% m/m)	RSEP (%)
FTIRM1	3	25:11	0.98	0.52	0.97	0.78	1.33
FTIRM2	1	12:60	0.51	11.24	0.49	11.61	29.9
FTIRM3	1	14:70	0.75	6.57	0.93	4.63	16.5
FTIRM4	4	60:20	0.84	6.29	0.80	7.03	19.8
NIRM1	1	25:11	0.72	8.45	0.70	8.82	23.3
NIRM2	1	12:60	0.84	5.26	0.84	5.25	15.2
NIRM3	3	14:70	0.99	1.15	0.99	1.21	3.45
NIRM4	1	60:20	0.77	1.77	0.69	2.05	3.51
NIRM5	1	48:16	0.69	1.91	0.76	1.71	2.85
RamanM1	1	25:11	0.70	8.49	0.80	6.74	19.0
RamanM2	1	12:60	0.84	5.52	0.83	6.57	17.8
RamanM3	1	14:70	0.76	7.62	0.83	9.16	23.9
RamanM4	4	60:20	0.98	0.54	0.95	0.82	1.40
RamanM5	4	48:16	0.94	0.96	0.93	0.91	12.1

FTIRM1, NIRM1 and RamanM1 modafinil lactose dilution; FTIRM2, NIRM2 and RamanM2 modafinil excipients dilution; FTIRM3, NIRM3 and RamanM3 modafinil excipients sequential addition; FTIRM4, NIRM4 and RamanM4 modafinil powdered tablets model; NIRM5 and RamanM5 modafinil intact tablet model; C:V calibration:validation ratio; F number of factors, r² correlation coefficient, RMSE:root mean square error