Table 4.
1H nuclear magnetic resonance peak integration and the ratios of sildenafil and co-former
| Reaction number | Co-former molecule/signal | Integrated value | Number of moleculesa | Ratios of sildenafil and co-formerb | ||
|---|---|---|---|---|---|---|
|
|
|
|||||
| Sildenafil (Signal V,–CH3) | Co-formers | Sildenafil | Co-formers | |||
| 22 | ASA/signal I (–CH3) | 3.92 | 3.92 | 1.30 | 1.30 | 1:1 |
| 25 | 3.02 | 3.27 | 1.01 | 1.09 | 1:1 | |
| 43 | FMA/signal I (–CH) | 3.00 | 4.76 | 1.00 | 2.38 | 1:2 |
| 46 | 3.00 | 4.62 | 1.00 | 2.31 | 1:2 | |
| 57 | BZA/signal III (–CH) | 3.00 | 3.38 | 1.00 | 1.69 | 1:2 |
| 61 | 3.00 | 3.85 | 1.00 | 1.92 | 1:2 | |
aNumber of molecules=Integrated value/number of protons at integrated chemical shift, bRatios of sildenafil and co-former=Number of sildenafil molecules: Number of co-former molecules. ASA: Acetylsalicylic acid or aspirin, FMA: Fumaric acid, BZA: Benzoic acid