Sustained release of theophylline from hydroxypropylcellulose tablets

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Theophylline is a common bronchodilator.
• Developing sustained-release formulations is crucial for improving patient compliance and therapeutic efficacy.

Purpose of the Study:

• To investigate the influence of hydroxypropylcellulose (HPC) properties on theophylline release from compressed tablets.
• To evaluate the in vitro and in vivo performance of these sustained-release theophylline tablets.

Main Methods:

• Compressed tablets were formulated using theophylline and varying grades and concentrations of hydroxypropylcellulose.
• In vitro drug release studies were conducted to assess the impact of polymer viscosity and content.
• In vivo salivary theophylline levels were monitored in human volunteers after oral administration.

Main Results:

• Theophylline release rate decreased significantly with increasing hydroxypropylcellulose viscosity grade.
• Higher polymer content in the tablets also led to a reduced drug release rate.
• In vivo studies demonstrated a low but sustained salivary theophylline concentration, confirming sustained drug release.

Conclusions:

• Hydroxypropylcellulose viscosity and content are critical factors in controlling theophylline release from sustained-release tablets.
• The developed tablet formulations show promise for effective in vivo sustained drug delivery.