The Effect of Tablet Formulation and Hardness on in Vitro Release of Cephalexin from Eudragit L100 Based Extended Release Tablets.

Abstract

Cephalexin is a semi synthetic antibiotic derived from cephalosporin 'C'. It is absorbed completely (80-100%) after oral administration 1) and having a biological half-life 2) of 1 h. To maintain therapeutic range, the drug should be administered 3-4 times a day, which leads to saw tooth kinetic and resulting in ineffective therapy. [3][4][5] Hence, we attempted to formulate extended release tablet, which can provide constant effective drug level for six hours, based on calculations considering pharmacokinetic parameters.The main objectives of the present work was to formulate cephalexin extended release tablets by using Eudragit L100 and to study the effect of polymer concentration and hardness on dissolution profile. The tablets were characterized by drug content, weight variation, hardness, thickness, friability, and stability. The in vitro release of formulated extended release tablet was compared with a marketed cephalexin extended release tablet. Eighteen batches of cephalexin extended release tablet were prepared by wet granulation method by using Eudragit L100. The effect of the concentration of Eudragit L100, microcrystalline cellulose and tablet hardness on cephalexin release was studied. The formulated tablets were also characterized for physical and chemical parameters. The dissolution results showed that a higher amount of Eudragit in tablet composition and higher tablet hardness resulted in reduced drug release. An increased amount of microcrystalline cellulose in tablet composition resulted in enhanced drug release. Tablet composition of 13.3% w/w Eudragit L100 and 6.6 to 8% w/w microcrystalline cellulose with hardness of 7-11 kg/cm 2 gave predicted release for 6 h. The in vitro release was compared with a marketed tablet. Physical and chemical parameters of all formulated tablets were within acceptable limits. The effect of storage on in vitro release and physicochemical parameters of tablets was evaluated and two batches among formulated eighteen batches found to be in acceptable limits. MATERIALS AND METHODS Materials

Hydroxypropyl Methylcellulose Based Cephalexin Extended Release Tablets: Influence of Tablet Formulation, Hardness and Storage on in Vitro Release Kinetics

“…Samples were with-drawn for every month of storage and evaluated 8) for appearance, hardness, drug content, and dissolution.…”

“…In our previous work, we reported 8) Eudragit L100 based cephalexin tablet with ideal release profile. In the present study we attempted to formulate cephalexin extended release tablet by using hydroxypropyl methylcellulose (HPMC), which is economic and the drug release from HPMC matrix is uniform irrespective of the pH.…”

“…Theory By considering pharmacokinetic parameters, we have calculated and reported 8) theoretical release profile of cephalexin for an ideal tablet. Briefly, the tablet should release 125 mg of cephalexin initially within first 1 h and 46.7 mg of cephalexin per hour for next 5 h from 375 mg of total dose in order to maintain plasma cephalexin concentration of 4.5 mg/l.…”

Eudragit E100 and Polysaccharide Polymer Blends as Matrices for Modified-Release Drug Delivery II: Swelling and Release Studies

“…In addition, matrices of the modified state polymer/polymer blends were harder than dry state polymer/polymer blends (results not shown). Studies have explicated that the harder the tablets, the slower the drug release and vice versa [16,17]. Harder tablets have less voids and pores and so the rate of drug release is reduced due to reduced channels of transport across the tablet matrix.…”

Development and evaluation of gastro-retentive drug delivery systems of cefuroxime axetil

“…Friability was tested by taking 10 dedusted tablets and the percentage friability was calculated. The percentage friability was measured using formula according to Saravanan et al (2002) and Banker and Anderson, 1990). …”