| No. | CAS # | Product Names | Molecular Formula |
| 301 | 72432-10-1 | Aniracetam | C12H13NO3 |
| 302 | 8007-70-3 | Anise oil | |
| 303 | 76822-34-9 | Anisodine hydrobromide | C17H21NO5.HBr |
| 304 | 874-90-8 | Anisonitrile | C8H7NO |
| 305 | 476-60-8 | Anthracene-1,4,9,10-tetraol | C14H10O4 |
| 306 | 88-68-6 | Anthranilamide | C7H8N2O |
| 307 | 1885-29-6 | Anthranilonitrile | C7H6N2 |
| 308 | 84-65-1 | Anthraquinone | C14H8O2 |
| 309 | 000000-00-0 | Anthroguinone Prapsynth | |
| 310 | 000000-00-0 | Anticorrosion agent | |
| 311 | 112568-12-4 | Antide | C82H108ClN17O14 |
| 312 | 7791-08-4 | Antimony chloride oxide | ClOSb |
| 313 | 12786-74-2 | Antimony dioxide | O2Sb |
| 314 | 6923-52-0 | Antimony triacetate | C6H9O6Sb |
| 315 | 7783-56-4 | Antimony trifluoride | |
| 316 | 26741-53-7 | Antioxidant 24 | C33H50O6P2 |
| 317 | 60-80-0 | Antipyrine | C11H12N2O |
| 318 | 520-36-5 | Apigenin | C15H10O5 |
| 319 | 9087-70-1 | Aprotinin | |
| 320 | 51025-85-5 | Arbekacin | C22H44N6O10 |
| 321 | 131707-23-8 | Arbidol hydrochloride | C22H25BrN2O3S.HCl |
| 322 | 497-76-7 | Arbutin | C12H16O7 |
| 323 | 300-08-3 | Arecoline hydrobromide | C8H13NO2.HBr |
| 324 | 141396-28-3 | Argatroban | C23H36N6O5S.H2O |
| 325 | 129722-12-9 | Aripiprazole | C23H27Cl2N3O2 |
| 326 | 53696-74-5 | Armillarisin A | C12H10O5 |
| 327 | 8008-93-3 | Armoise oil | |
| 328 | 87129-71-3 | Arnolol | C14H23NO3 |
| 329 | 1327-53-3 | Arsenic(III) oxide | As2O3 |
| 330 | 63968-64-9 | Artemisinin | C15H22O5 |
| 331 | 88495-63-0 | Artesunate | C19H28O8 |
| 332 | 23964-58-1 | Articaine | C13H20N2O3S |
| 333 | 50-81-7 | ascorbic acid | C6H8O6 |
| 334 | 137-66-6 | Ascorbyl palmitate | C22H38O7 |
| 335 | 464-92-6 | Asiatic acid | C30H48O5 |
| 336 | 22839-47-0 | Aspartame | C14H18N2O5 |
| 337 | 62952-06-1 | Aspirin DL-lysine | C9H8O4.C6H14N2O2;C15H22N2O6 |
| 338 | 50-78-2 | Aspirin | C9H8O4 |
| 339 | 472-61-7 | Astaxanthin | C40H52O4 |
| 340 | 68844-77-9 | Astemizole | C28H31FN4O |
| 341 | 84687-42-3 | Astragaloside III | C41H68O14 |
| 342 | 84676-89-1 | Astragaloside II | C43H70O15 |
| 343 | 84687-43-4 | Astragaloside IV | C41H68O14 |
| 344 | 89250-26-0 | Astragalus pulysacharide | C10H7ClN2O2S |
| 345 | 2302-17-2 | Asulam sodium salt | C8H9N2NaO4S |
| 346 | 3337-71-1 | Asulam | C8H10N2O4S |
| 347 | 229975-97-7 | Atazanavir sulfate | C38H52N6O7.H2SO4 |
| 348 | 198904-31-3 | Atazanavir | C38H52N6O7 |
| 349 | 29122-68-7 | Atenolol | C14H22N2O3 |
| 350 | 82248-59-7 | Atomoxetine hydrochloride | C17H21NO.HCl |