Trivedi2018_Article_IntercalatedTheophylline-smect.pdf (1.24 MB)
Intercalated theophylline-smectite hybrid for pH-mediated delivery
journal contribution
posted on 2023-06-20, 14:17 authored by Vivek Trivedi, Uttom Nandi, Mohammed Maniruzzaman, Nichola J ColemanOn the basis of their large specific surface areas, high adsorption and cation exchange capacities, swelling potential and low toxicity, natural smectite clays are attractive substrates for the gastric protection of neutral and cationic drugs. Theophylline is an amphoteric xanthine derivative that is widely used as a bronchodilator in the treatment of asthma and chronic obstructive pulmonary disease. This study considers the in vitro uptake and release characteristics of the binary theophylline-smectite system. The cationic form of theophylline was readily ion exchanged into smectite clay at pH 1.2 with a maximum uptake of 67 ± 2 mg g-1. Characterisation of the drug-clay hybrid system by powder X-ray diffraction analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy confirmed that the theophylline had been exclusively intercalated into the clay system in an amorphous form. The drug remained bound within the clay under simulated gastric conditions at pH 1.2; and the prolonged release of approximately 40% of the drug was observed in simulated intestinal fluid at pH 6.8 and 7.4 within a 2-h timeframe. The incomplete reversibility of the intercalation process was attributed to chemisorption of the drug within the clay lattice. These findings indicate that smectite clay is a potentially suitable vehicle for the safe passage of theophylline into the duodenum. Protection from absorption in the stomach and subsequent prolonged release in the small intestine are advantageous in reducing fluctuations in serum concentration which may impact therapeutic effect and toxicity.
History
Publication status
- Published
File Version
- Published version
Journal
Drug Delivery and Translational ResearchISSN
2190-393XPublisher
Springer VerlagExternal DOI
Issue
6Volume
8Page range
1781-1789Department affiliated with
- Chemistry Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2018-01-24First Open Access (FOA) Date
2018-01-24First Compliant Deposit (FCD) Date
2018-01-24Usage metrics
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