Pharmaceutical Development and Clinical Pharmacokinetic Evaluation of Gastroretentive Floating Matrix Tablets of Levofloxacin

The most common approach for achieving sustained drug release is by the use of hydrophilic polymeric excipients directly compressed with active ingredients into tablets. Hydrophilic polymers swell in the presence of water to form hydrogel structures from which drugs are released by slow diffusion. The purpose of this study was to prepare a floating drug delivery system of levofloxacin, a fluoroquinolone antibiotic. Levofloxacin is highly soluble in acidic media and precipitates in alkaline media, thereby losing its solubility. We designed a gastroretentive system of levofloxacin to enhance bioavailability by retaining them in the acidic environment of the stomach. Tablets were prepared by the direct compression technique using polymers such as hydroxypropylmethylcellulose (HPMC K4M, HPMC K15M, and HPMC K100M). Sodium bicarbonate was utilized as a gas-generating agent. Tables were evaluated for their physical characteristics such as hardness, thickness, friability, weight variation, drug content, swelling studies, and floating properties. Tablet formulations were evaluated by in vitro dissolution studies. Formulations showed a floating lag time of 30 seconds and a floating time above 12 hours. Among these formulations F3, F7 and F11 exhibited controlled and prolonged drug release profiles while floating over the dissolution medium. The best formulation (F3) was selected based on in vitro characteristics and further tested in healthy volunteers by radiographic studies of tablets by incorporating BaSO4. These clinical studies revealed that the tablets remained in the stomach for 240 ± 30 minutes in fasting human volunteers, indicating gastric retention of the system.