In the pharmaceutical industry, Phenytoin 100 mg is a first-line Hydantoin-class Anticonvulsant. As a pharmacist and manufacturer, I classify this as a “voltage-gated channel blocker.” It is one of the most widely used and cost-effective medications for the long-term management of epilepsy worldwide.
Primary Clinical Uses
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Generalized Tonic-Clonic Seizures: Primary treatment for grand mal seizures.
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Complex Partial Seizures: Management of focal seizures that affect awareness.
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Status Epilepticus: Used as a loading dose (often in injectable form) to prevent the recurrence of seizures after they have been acutely stopped by benzodiazepines.
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Post-Neurosurgery Prophylaxis: Given to patients following brain surgery or head trauma to prevent “provoked” seizures.
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Trigeminal Neuralgia (Off-label): Occasionally used for nerve pain when first-line agents like Carbamazepine are not tolerated.
Mechanism of Action: Frequency-Dependent Blockade
Phenytoin works by selectively stabilizing hyper-excited neuronal membranes without significantly depressing normal brain activity.
Sodium Channel Binding: It binds to voltage-gated sodium channels while they are in their inactive state.
Prolonging Inactivation: By keeping these channels closed for longer periods, it prevents the high-frequency repetitive firing of action potentials.
Selective Inhibition: This is “use-dependent,” meaning it primarily targets neurons that are firing abnormally fast (the seizure focus) while leaving normal-speed neurons mostly unaffected.
The Manufacturer’s Perspective: Formulation & Export
From a production and global trade standpoint at your WHO-GMP facility in Mumbai, Phenytoin 100 mg is a technically demanding product:
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The Bioavailability Challenge: Phenytoin has a narrow therapeutic index and follows nonlinear (Michaelis-Menten) kinetics. Small changes in formulation can lead to massive changes in blood levels. As a firm owner, your Dissolution Profile must be perfectly consistent to avoid toxicity or treatment failure.
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Phenytoin Sodium vs. Phenytoin Base: In the export market, we typically manufacture Phenytoin Sodium. You must clearly state this on your digital platform, as 100 mg of Phenytoin Sodium is only equivalent to approximately 92 mg of Phenytoin Base.
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Teratogenic Warning: As a pharmacist, you must ensure the Product Information Leaflet (PIL) includes the “Fetal Hydantoin Syndrome” warning, as it is a Category D drug in pregnancy.
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Stability & Packaging: Phenytoin is moisture-sensitive. We utilize Alu-Alu blister packaging or HDPE bottles with induction seals to ensure a 36-month shelf life for export to Zone IVb regions.