The CAS registry number of Benzathine penicillin G is 41372-02-5. In addition, the molecular formula is C₁₆H₂₀N₂.2C₁₆H₁₈N₂O₄S.4H₂O and the molecular weight is 981.18. The IUPAC name is N,N'-dibenzylethane-1,2-diamine;(2S,5R,6R)-3,3-dimethyl-7-oxo-6-[(2-phenylacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid; tetrahydrate. What's more, it should be stored in sealed container, and put in a cool and dry place.

Physical properties about Benzathine penicillin G are: (1)ACD/LogP: 0.67; (2)# of Rule of 5 Violations: 3; (3)ACD/BCF (pH 5.5): 1; (4)ACD/BCF (pH 7.4): 1; (5)ACD/KOC (pH 5.5): 1; (6)ACD/KOC (pH 7.4): 1; (7)#H bond acceptors: 18; (8)#H bond donors: 14; (9)#Freely Rotating Bonds: 15; (10)Polar Surface Area: 227.84 Å²; (11)Flash Point: 739.9 °C; (12)Enthalpy of Vaporization: 204.26 kJ/mol; (13)Boiling Point: 1299.8 °C at 760 mmHg; (14)Vapour Pressure: 0 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES: O=C(O)[C@@H]2N3C(=O)[C@@H](NC(=O)Cc1ccccc1)[C@H]3SC2(C)C.O=C3N1[C@@H](C(=O)O)C(S[C@@H]1[C@@H]3NC(=O)Cc2ccccc2)(C)C.O.O.O.O.c1ccccc1CNCCNCc2ccccc2
(2)Std. InChI: InChI=1S/2C16H18N2O4S.C16H20N2.4H2O/c2*1-16(2)12(15(21)22)18-13(20)11(14(18)23-16)17-10(19)8-9-6-4-3-5-7-9;1-3-7-15(8-4-1)13-17-11-12-18-14-16-9-5-2-6-10-16;;;;/h2*3-7,11-12,14H,8H2,1-2H3,(H,17,19)(H,21,22);1-10,17-18H,11-14H2;4*1H2/t2*11-,12+,14-;;;;;/m11...../s1
(3)Std. InChIKey: WIDKTXGNSOORHA-CJHXQPGBSA-N