Physicochemical Analysis and Molecular Modeling of the Fosinopril β-Cyclodextrin Inclusion Complex

Table 1

Heats of formation, kJ/mol, calculated with the PM3 method for the geometry optimized free host (), free guest (), and complex (), respectively, and also the single point energy values for the host structure () and guest structure (), respectively, taken from the optimized complex geometry for the two possible forms (salt and ionic) of fosinopril and the three conformations taken to account for free FOS: (a) the nearest stable conformation to the crystal structure; (b) the global minimum energy conformation; (c) the nearest stable conformation to the FOS geometry in the complex; 1, 2, and 3 correspond to the three energy minima obtained by MM+ optimization.

Min	Form
			(a)	(b)	(c)
1	COONa	−6095.50	−1793.36	−1859.43	−1790.29	−7958.69	−6094.07	−1778.24
2	COONa				−1786.44	−7942.88	−6078.99	−1780.79
3	COONa				−1828.14	−8108.27	−6055.86	−1717.76
1	COO^−	−6095.50	−1667.52	−1741.00	−1693.78	−7891.67	−6091.18	−1689.72
2	COO^−				−1697.11	−7922.78	−6071.46	−1685.99
3	COO^−				−1695.59	−8018.88	−6042.21	−1646.09