Pantoprazole Magnesium Dihydrate API is a pharmaceutical proton pump inhibitor salt of pantoprazole used in the development and manufacture of oral acid-suppressing medicines. It belongs to the substituted benzimidazole class of proton pump inhibitors (PPIs) and is associated with inhibition of gastric acid secretion by targeting the gastric H⁺/K⁺-ATPase proton pump in gastric parietal cells.
Pantoprazole Magnesium Dihydrate is chemically different from Pantoprazole Sodium and anhydrous Pantoprazole Magnesium. The dihydrate contains magnesium and two molecules of water of crystallization. Pharmaceutical references identify the compound as magnesium bis[5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazolide] dihydrate. Its molecular formula is C₃₂H₃₂F₄MgN₆O₁₀S₂, with a molecular weight of approximately 825.06–825.08 g/mol.
The dihydrate form is particularly important for pharmaceutical manufacturing because water of crystallization contributes to its defined molecular form and physical properties. The Canadian pharmaceutical monograph describes Pantoprazole Magnesium as a white to beige powder and identifies the drug substance as the dihydrate.
Pantoprazole Magnesium Dihydrate is associated with the proton pump inhibitor (PPI) class. PPIs suppress gastric acid secretion by inhibiting the gastric H⁺/K⁺-ATPase enzyme system responsible for the final step of gastric acid secretion.
Pantoprazole is a substituted benzimidazole that accumulates in the acidic environment of gastric parietal cells. It is converted to its active sulfenamide form under acidic conditions and subsequently binds to the proton-translocating region of the H⁺/K⁺-ATPase. This produces inhibition of both basal and stimulated gastric acid secretion.
Pantoprazole Pharmaceutical API acts at the gastric proton pump rather than directly blocking histamine, gastrin or acetylcholine receptors. Because its action occurs at the final common pathway of gastric acid secretion, pantoprazole can inhibit acid secretion regardless of the initiating stimulus.
The active compound becomes concentrated within the acidic canalicular environment of gastric parietal cells. Its activity is strongly pH dependent, with activation occurring under acidic conditions. The Canadian monograph reports that pantoprazole exerts its effect in an environment below approximately pH 3 and is predominantly inactive at higher pH.
Pantoprazole Magnesium Dihydrate API is used in the pharmaceutical industry for manufacturing oral dosage forms containing pantoprazole. The Canadian product monograph identifies pantoprazole magnesium tablets for conditions where reduction of gastric acid secretion is required, including duodenal ulcer, gastric ulcer, reflux esophagitis, symptomatic gastroesophageal reflux disease and H. pylori-associated duodenal ulcer.
Pantoprazole magnesium 40 mg tablets have also been clinically compared with pantoprazole sodium 40 mg tablets. The Canadian monograph reports comparable acid-control effects and comparable healing outcomes for reflux esophagitis.
Pantoprazole Magnesium Dihydrate has limited aqueous solubility that varies with pH. The Canadian pharmaceutical monograph reports a water solubility of approximately 3.39 × 10⁻⁴ mol/L at 37°C at water pH 8.24–8.74. Solubility increases in alkaline and buffered conditions. The reported solubility at pH 7.4 is 6.70 × 10⁻⁴ mol/L at 37°C, while at pH 11 it is 9.98 × 10⁻⁴ mol/L at 37°C.
The same source reports solubility in methanol of 3.58 × 10⁻² mol/L at 22–24°C and ethanol of 3.63 × 10⁻³ mol/L at 22–24°C.
The reported pKa values for Pantoprazole Magnesium are 3.77 ± 0.02 and 8.11 ± 0.02 at 25°C. The reported logD at pH 7.4 is 2.02 ± 0.01. These properties contribute to the compound's pH-dependent behavior and pharmaceutical formulation characteristics.
The dihydrate form contains two molecules of water of crystallization. A theoretical water content calculated from the molecular formula is approximately 4.37% w/w. Published patent literature concerning pantoprazole magnesium dihydrate reports water-content ranges around 4.0–5.0%, with 4.2–4.6% described as corresponding closely to the dihydrate form. These values are useful as solid-state references but should not automatically be treated as a universal API release specification.
A Pantoprazole Magnesium Dihydrate API Manufacturer should control the specific hydrate form because the anhydrous and hydrated materials have different molecular weights and water content. Appropriate pharmaceutical quality control can include identity testing, assay, related substances, water determination, residual solvents, elemental impurities and solid-state characterization.
Analytical characterization can include HPLC/UHPLC, IR spectroscopy, mass spectrometry, water determination by Karl Fischer analysis, X-ray powder diffraction and other validated methods. XRPD can be particularly useful when confirmation of the dihydrate solid form is required.
For Pantoprazole Magnesium Dihydrate API Supplier India searches, accurate naming is important because Pantoprazole Sodium, Pantoprazole Magnesium Anhydrous and Pantoprazole Magnesium Dihydrate are distinct chemical forms.
The pharmaceutical monograph confirms that Pantoprazole Magnesium Dihydrate is used as the active pharmaceutical ingredient in enteric-coated tablet products. The Canadian product monograph reports storage of the finished pantoprazole magnesium product between 15°C and 30°C in recommended packaging. API storage should follow the validated manufacturer's stability program and controlled specification.
A pharmaceutical-grade Pantoprazole Magnesium Dihydrate Bulk API may be supplied with:
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 0.5% |
| Specific Rotation | 4.0–5.0%* |