Table 2.
The peak absorbance value of the infrared spectra of free primaquine (PQ), free chloroquine (CQ), blank liposomes (Lipo-Blank), primaquine-loaded liposomes (Lipo-PQ), chloroquine-loaded liposomes (Lipo-CQ), and liposome co-loaded with primaquine and chloroquine (Lipo-PQCQ).
| Functional groups | Wavenumber (cm−1) | ||||||
|---|---|---|---|---|---|---|---|
| Ref | Prima-quine | Chloro-quine | Lipo-Blank | Lipo-PQ | Lipo-CQ | Lipo-PQCQ | |
| O–H/N–H stretching | 3550–3200 | 3297 | 3411; 3236 | 3442 | 3441 | 3441 | 3437 |
| CH3, CH2, CH stretching | 3000–2850 | 2968; 2945; 2883 | 2969; 2935; 2850 | 2956; 2919; 2851 | 2920; 2851 | 2924 | 2923 |
| R–CO–OR’ (carbonyl ester) | 1740 | – | – | 1738 | 1739 | – | – |
| C=C stretching | 1630–1680 | – | – | 1636 | 1636 | 1632 | 1638 |
| C–C ring stretching (quinolone) | 1612 | 1612 | 1614 | – | – | – | – |
| C–N stretching | 1558 | 1533 | 1552 | – | – | – | – |
| CH2, CH3 bending | 1470–1350 | 1469; 1430; 1385 | 1458; 1393; 1368 | 1467; 1384 | 1384 | 1458; 1384 | 1457; 1384 |
| R–PO2− –R’ (diester phosphate) | 1250–1220 | 1234 | 1245 | 1254 | 1253 | – | – |
| C–O stretching | 1250–970 | 1165 | 1132 | 1120 | 1165 | 1121 | 1121 |
| P–O Asymmetric stretching | 1058 | 1050 | 1065 | 1067 | 1070 | 1074 | 1066 |
| N+–CH3 (choline) | 970 | – | – | – | – | – | – |
| =C–H, =CH2 | 995–880 | 953;899 | 942; 907; 881 | 951; 863 | 950; 861 | 953; 863 | 952; 865 |