Lungs, anatomy hand drawn illustration

Beta-cyclodextrin containing theophylline formulation of rapid, but also prolonged adsorption profile: exploiting interaction characterized with Bs type of isotherm

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Modi Mundi Pharma Pvt Ltd., India has developed a beta-cyclodextrin containing oral dosage form of 400 mg theophylline marketed under trade name Unicontin-E 400 Tablet CR. The beta-cyclodextrin (BCD) content is not disclosed, but due to obvious size limitations of a tablet form and the relatively high API dosage weight, it is quite likely that the application of BCD is sub-stoichiometric in this product.

Amongst 46 APIs which are also marketed in oral BCD formulations [1], theophylline is peculiar known for its interaction with beta-cyclodextrin that may be characterized with a Bs type of isotherm. This feature may be exploited by a unique absorption profile as highlighted by Ammar et al.: “The pharmacokinetic parameters including Cmax, tmax, Cmin, t1/2, Ke, MRT and AUC revealed that inclusion complexation of theophylline in B-cyclodextrin results in not only an improvement in the bioavailability of the drug, but also to acquired sustained release properties for the drug. [2]” Uncomplexed theophylline absorbs quickly and possesses narrow therapeutic index, i.e. there is a low range between the safe and toxic serum concentrations of this drug, hence another justification for the development of a modified pharmacokinetic profile formulation.

Unicontin-E 400 Tablet CR is used to treat and prevent symptoms of asthma and chronic obstructive pulmonary disorder (a lung disorder in which flow of air to the lung is blocked). It helps in relaxing the muscles of the air passages, thus widening it and making it easier to breathe. The beta-cyclodextrin modified release kinetics helps revealing the complaints quickly as well as for a longer period of time.

[1] Puskás, I., Szente, L., Szőcs, L., Fenyvesi, É. “Recent List of Cyclodextrin-Containing Drug Products”, Periodica Polytechnica Chemical Engineering, 67(1), pp. 11–17, 2023.

[2] Ammar HO, Ghorab M, El-nahhas SA, Omar SM, Ghorab MM. Improvement of some pharmaceutical properties of drugs by cyclodextrin complexation. 5. Theophylline. Pharmazie. 1996 Jan;51(1):42-6. PMID: 8999434.

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