Development of gastroretentive drug delivery system for cefuroxime axetil: in vitro and in vivo evaluation in human volunteers.

The objective of this investigation was to develop the cefuroxime axetil sustained-release floating tablets to prolong the gastric residence time and compare their pharmacokinetic behavior with marketed conventional tablets (Zocef). The floating tablets were developed using polymers like HPMC K4M and HPMC K100M alone, and polymer combination of HPMC K4M and Polyox WSR 303 by effervescent technique. Tablets were prepared by slugging method and evaluated for their physical characteristics, in vitro drug release, and buoyancy lag time. The best formulation (F10) was selected based on in vitro characteristics and used in vivo radiographic and bioavailability studies in healthy human volunteers. All the formulations could sustain drug release for 12 h. The dissolution profiles were subjected to various kinetic release models and it was found that the mechanism of drug release followed Peppas model. The in vivo radiographic studies revealed that the tablets remained in stomach for 225 ± 30 min. Based on in vivo performance, the developed floating tablets showed superior bioavailability than Zocef tablet. Based on in vivo performance significant difference was observed between Cmax, tmax, t1/2, AUC0-∞, and mean residence time of test and reference (p<0.05). The increase in relative bioavailability of test was 1.61 fold when compared to reference.

Development and evaluation of gastroretentive norfloxacin floating tablets.

Floating matrix tablets of norfloxacin were developed to prolong gastric residence time, leading to an increase in drug bioavailability. Tablets were prepared by the wet granulation technique, using polymers such as hydroxypropyl methylcellulose (HPMC K4M, HPMC K100M) and xanthan gum. Tablets were evaluated for their physical characteristics, viz., hardness, thickness, friability, and mass variation, drug content and floating properties. Further, tablets were studied for in vitro drug release characteristics for 9 hours. The tablets exhibited controlled and prolonged drug release profiles while floating over the dissolution medium. Non-Fickian diffusion was confirmed as the drug release mechanism from these tablets, indicating that water diffusion and polymer rearrangement played an essential role in drug release. The best formulation (F4) was selected based on in vitro characteristics and was used in vivo radiographic studies by incorporating BaSO4. These studies revealed that the tablets remained in the stomach for 180 +/- 30 min in fasting human volunteers and indicated that gastric retention time was increased by the floating principle, which was considered desirable for the absorption window drugs.

Development of sustained release floating drug delivery system for norfloxacin: in vitro and in vivo evaluation.

Norfloxacin is a drug with an absorption window. Its oral bioavailability is 30-40% and is a case for improvement by appropriate formulation design. In our previous study, gastroretentive floating tablets for norfloxacin were developed employing three different polymers such as HPMC K4M, HPMC K100M, and xanthan gum. The purpose of this investigation is to further improve and evaluate the in vitro and in vivo performance of the prepared floating tablets by inclusion of citric acid as an acidifier, which is also useful in a fed state. The prepared tablets were characterized and found to exhibit satisfactory physico-chemical characteristics. The effects of citric acid at different concentrations on drug release and floating properties were studied. All the prepared batches showed good in vitro buoyancy. It was observed that the tablets remained buoyant for 24 h. The best formulation (F4c), consisting of 1.5% citric acid and 18% HPMC K4M, was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate. These studies revealed that the tablets remained in the stomach for 205 ± 8.4 min in fasting human volunteers. In vivo studies were carried out for the best formulation in eight healthy male human volunteers, and the pharmacokinetic parameters of the developed formulation were compared with marketed conventional (Norbid) tablets. Based on the in vivo performance in a two-way, crossover study design in healthy subjects, the developed floating tablets showed superior bioavailability than the Norbid tablets. The increased bioavailability of developed formulation was found to be 16.27%. LAY ABSTRACT: Norfloxacin is a broad-spectrum antibiotic used to treat bacterial infections such as respiratory and urinary tract infections. Conventional norfloxacin tablets show incomplete drug absorption resulting in lower bioavailabilty. Norfloxacin is better absorbed in the stomach. The dosage forms that remain in the stomach are referred to as gastroretentive drug delivery systems. Gastroretentive floating tablets of norfloxcin were developed by employing three different polymers, which prolonged the drug release from the dosage forms. Tablet floatation was achieved by an effervescent mechanism. Citric acid at different concentrations was used in formulations to provide an acidic microenvironment. The prepared tablets were characterized for hardness, weight variation, thickness, friability, floating lag time, and dissolution. Around 12 tablet formulations were prepared as a continuation of the previous work. The best formulation (F4c) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent. The tablets remained in the stomach for about 205 ± 8.4 min. Bioavailability studies were conducted in healthy male human volunteers, and the pharmacokinetic parameters of the best formulation were compared with that of the marketed conventional (Norbid) tablet. The increased bioavailability of the developed formulation was found to be 16.27%.