TABLE 5.

Parameters related to energy transfer of bovine serum albumin with linagliptin, rabeprazole sodium, and their 1:1 complex at room temperature

Ligand	E (%)	J (×10–18 cm3 L mol–1)	R 0 (nm)	r (nm)
LG	14.53	4.737	0.71	0.95
RS	27.46	3.981	0.69	0.81
LG‐RS	27.81	4.99	0.72	0.84

Abbreviations: BSA, bovine serum albumin; E, efficiency of energy transfer; LG, linagliptin; RS, rabeprazole sodium.

Note: r represents the distance between protein and ligand, and R ₀ represents the critical distance found at 50% transfer efficiency. According to the Förster theory, the distance between ligand and protein was tabulated precisely. For all the systems, the observed values of distance were <8 nm.