Development and in vitro evaluation of an oral floating matrix tablet formulation of diltiazem hydrochloride

Abstract

The purpose of this research was to prepare a floating drug delivery system of diltiazem hydrochloride (DTZ). Floating matrix tablets of DTZ were developed to prolong gastric residence time and increase its bioavailability. Rapid gastrointestinal transit could result in incomplete drug release from the drug delivery system above the absorption zone leading to diminished efficacy of the administered dose. The tablets were prepared by direct compression technique, using polymers such as hydroxypropylmethylcellulose (HPMC, Methocel K100M CR), Compritol 888 ATO, alone or in combination and other standard excipients. Sodium bicarbonate was incorporated as a gas-generating agent. The effects of sodium bicarbonate and succinic acid on drug release profile and floating properties were investigated. A 3(2) factorial design was applied to systematically optimize the drug release profile. The amounts of Methocel K100M CR (X1) and Compritol 888 ATO (X2) were selected as independent variables. The time required for 50% (t50) and 85% (t85) drug dissolution were selected as dependent variables. The results of factorial design indicated that a high level of both Methocel K100M CR (X1) and Compritol 888 ATO (X2) favors the preparation of floating controlled release of DTZ tablets. Comparable release profiles between the commercial product and the designed system were obtained. The linear regression analysis and model fitting showed that all these formulations followed Korsmeyer and Peppas model, which had a higher value of correlation coefficient (r). While tablet hardness had little or no effect on the release kinetics and was found to be a determining factor with regards to the buoyancy of the tablets.

Preparation of multiple-unit floating-bioadhesive cooperative minitablets for improving the oral bioavailability of famotidine in rats

“…The formulations containing higher NaHCO 3 ratios -10 % w/w (F6) and 20 % w/w (F7) had significantly shorter floating lag time (1 min) than other formulations. Moreover, a similar conclusion was noted by Gambhire et al (2007) who concluded that as the percentage of NaHCO 3 increases, the floating lag time decreases. This phenomenon might be due to the generation of larger amounts of effervescence with higher NaHCO 3 percentage which led to an increase in the rate of pore formation and consequently rapid hydration of the minitablets' matrices.…”

Design and Evaluation of an Oral Floating Matrix Tablet of Salbutamol Sulphate

“…The samples were analyzed for drug release by measuring the absorbance at 225 nm spectrophotometrically (UV-1800, Shimadzu, Japan) after suitable dilution. All determinations were performed in triplicate [5][6][7][8].…”

In Vitro and in Vivo Evaluation of the Gastroretentive Floating Dosage Form

“…Absorbance of these solutions was measured at 285 nm using a UV/Visible spectrophotometer. The percentage drug release was plotted against time to determine the release profile 14 .…”