Pharmaceutical availability of gliclazide from selected matrix formulation tablets.

BACKGROUND

Immediate release and modified release gliclazide formulation tablets are available on the market. We decided to measure the kinetics of gliclazide release from these tablets, and to propose our own technique for producing gliclazide matrix tablets, comparing their release kinetic profile with the gliclazide tablets available on the market.

MATERIAL/METHODS: A BP 2001 dissolution test was performed for selected gliclazide formulation tablets, and the water solubility of authentic gliclazide samples from different manufacturers was determined by UV spectrometry.

RESULTS

Diabezidum (Jelfa) and diabrezide (Molteni) tablets are classic gliclazide oral formulations, releasing the drug very rapidly in vivo and in vitro according to BP 2001 (approximately 99% at 100 min). However, diaprel tablets (Servier) are modified release formulations (67% released in in vitro conditions at 8 h). The matrix tablets (C) produced according to our own formula demonstrated a release profile similar to diaprel tablets. The MDT, calculated in order to classify the tablets we studied, ranged from 4.6 to 76.4 minutes for immediate release (IR) tablets (diabrezide, diabezidum, I and F), and from 279.6 to 701.2 minutes for sustained-release (SR) tablets (E, G, C, diaprel, J, B, D, H, K, A).

CONCLUSIONS

The dissolution process of immediate release gliclazide formulation tablets (diabrezide, diabezidum, F, I) obeys a first-order equation. However, the process for modified release formulation tablets (diaprel, diaprel MR, A, B, C, D G, H, J, K) proceeds according to a zero-order equation.