Spectroscopic and computational insights into theophylline/β-cyclodextrin complexation: inclusion accomplished by diverse methods

Abstract

Current scenario in asthmatic prevalence worldwide calls for a facile, cost-effective, and energy efficient methodology to formulate the potent bronchodilator, theophylline (THP), into an effective dosage forms. Since the uses of THP are severely impeded by its poor aqueous solubility and low bioavailability, solid inclusion complexes (ICs) of THP in β-cyclodextrin (β-CD) were prepared to overcome the limitations. The ICs were developed by conventional methods and also by microwave irradiation method, which is environmentally more benign and requires lesser reaction time. The complexation phenomenon was effectual by the co-precipitation, freeze-drying, and microwave methods as affirmed from various spectroscopic analyses. ¹H NMR and molecular docking studies illustrated the total inclusion of THP into β-CD cavity. Better efficacy of the microwaved product was witnessed in terms of drug content, dissolution, and anti-biofilm activities. Thus microwave irradiation can be utilised as a naive and economical methodology to design β-CD–THP dosage formulations.

Keywords:

• Theophylline
• β-cyclodextrin
• solid inclusion complexes
• microwave irradiation
• dissolution

Acknowledgements

The authors thank Prof. Mahendra Kumar Modi, Coordinator, Distributed Information Centre, Department of Agricultural Biotechnology, Assam Agricultural University, Assam, for rendering computational facility. Subhrajit Mohanty thanks NIT Rourkela, India for research fellowship.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

U. Subuddhi thanks the Department of Science and Technology, India for the financial assistance through the DST Fast Track Young Scientist Scheme (SR/FT/CS-76/2010)