The Cefapirin, with the CAS registry number 21593-23-7, is also known as 7-[2-(4-Pyridylthio)acetamido]cephalosporanic acid. It belongs to the product categories of Aromatics; Chiral Reagents; Heterocycles; Intermediates & Fine Chemicals; Pharmaceuticals; Sulfur & Selenium Compounds. Its EINECS number is 244-466-5. This chemical's molecular formula is C₁₇H₁₇N₃O₆S₂ and molecular weight is 423.47. What's more, its systematic name is (6R,7R)-3-(Acetoxymethyl)-8-oxo-7-{[(4-pyridinylsulfanyl)acetyl]amino}-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid. Its classification codes are: (1)Anti-Bacterial Agents; (2)Anti-Infective Agents; (3)Antibiotics; (4)Drug / Therapeutic Agent; (5)Human Data. It is a kind of cephalosporin antibiotic, partly plasma-bound, that is effective against gram-negative and gram-positive organisms. 

Physical properties of Cefapirin are: (1)ACD/LogP: -0.412; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -3.17; (4)ACD/LogD (pH 7.4): -4.11; (5)ACD/BCF (pH 5.5): 1.00 ; (6)ACD/BCF (pH 7.4): 1.00; (7)ACD/KOC (pH 5.5): 1.00; (8)ACD/KOC (pH 7.4): 1.00; (9)#H bond acceptors: 9; (10)#H bond donors: 2; (11)#Freely Rotating Bonds: 8; (12)Polar Surface Area: 176.5 Å²; (13)Index of Refraction: 1.689; (14)Molar Refractivity: 102.748 cm³; (15)Molar Volume: 269.145 cm³; (16)Polarizability: 40.733×10^-24cm³; (17)Surface Tension: 83.9 dyne/cm; (18)Density: 1.573 g/cm³; (19)Flash Point: 427.889 °C; (20)Enthalpy of Vaporization: 119.627 kJ/mol; (21)Boiling Point: 783.902 °C at 760 mmHg; (22)Vapour Pressure: 0 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES: O=C2N1/C(=C(\CS[C@@H]1[C@@H]2NC(=O)CSc3ccncc3)COC(=O)C)C(=O)O
(2)Std. InChI: InChI=1S/C17H17N3O6S2/c1-9(21)26-6-10-7-28-16-13(15(23)20(16)14(10)17(24)25)19-12(22)8-27-11-2-4-18-5-3-11/h2-5,13,16H,6-8H2,1H3,(H,19,22)(H,24,25)/t13-,16-/m1/s1
(3)Std. InChIKey: UQLLWWBDSUHNEB-CZUORRHYSA-N

The toxicity data is as follows: