Therapeutically inert excipient in pharmaceutical formulation preserved excise exemption for Flagyl tablets.

Calcium carbonate in Flagyl tablets was treated as a therapeutically inert pharmaceutical necessity and not as an active ingredient that would disqualify the tablets from the excise exemption under the Rule 8 notification. The formulation contained metronidazole as the only active therapeutic ingredient, while calcium carbonate appeared only in small quantities. Since calcium carbonate acts as an antacid only in much larger doses and the drug authority certified metronidazole as the sole active ingredient, it was regarded as a diluent that did not interfere with the therapeutic or prophylactic activity of the scheduled ingredient. The tablets therefore satisfied the notification conditions and qualified for concessional exemption.

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Issues: Whether calcium carbonate used in Flagyl tablets was a therapeutically inert pharmaceutical necessity so as not to disqualify the tablets from the excise exemption under the notification issued under Rule 8 of the Central Excise Rules, 1944.

Analysis: The notification exempted patent or proprietary medicines containing the specified ingredient, subject to the condition that any additional pharmaceutical necessity must be therapeutically inert and must not interfere with the therapeutic or prophylactic activity of the scheduled ingredient. The composition of the tablets showed metronidazole as the only active therapeutic ingredient, while calcium carbonate was present in small quantities. The material on record showed that calcium carbonate acts as an antacid only in much larger doses, and the competent food and drug authority certified metronidazole as the only active ingredient. On that basis, calcium carbonate in the formulation functioned as a diluent and remained therapeutically inert for the tablets in question.

Conclusion: The tablets satisfied the condition in the notification and were entitled to the concessional exemption.

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