Design Development and in Vitro Characterization of Glibenclamide Liquisolid Tablet

Glibenclamide is an antidiabetic drug which belongs to the class sulfonyl ureas. It is poorly water soluble and hence have less oral bioavailability of about 40%. Since Glibenclamide is a poorly soluble drug it is classified under class II drugs as per BCS classification. Solubility plays a vital role in determining the invitro absorption of the drug, and hence the problem of poor solubility needs to be addressed with great care in formulating poorly soluble drugs. Among the various method adopted to increase the solubility of drugs, liquisolid technique seems to be a promising technology. The aim and objective of the study was to improve the solubility and dissolution characteristics of Glibenclamide using liquisolid technology. Solubility is one of the major factors which affects the in vivo performance of the drug. Poorly soluble drugs throw a stiff challenge to the formulation scientists in producing a dosage form for such drugs with satisfactory dissolution profile. Among the various mechanisms used for improving the solubility and thereby the dissolution of these drugs, liquisolid technique is gaining much attention and importance in recent years. The availability of drug in the solubilised form and increase in the wettability of the powders by the dissolution media were some of the proposed mechanisms to explain the enhanced dissolution rate of poorly soluble drugs from such formulations. Hence, in this study, liquisolid technique was chosen to enhance the dissolution properties of Glibenclamide. The Glibenclamide liquisolid compacts were prepared by using propylene glycol as the non volatile liquid vehicle. Avicel PH 102 and Aerosil 200 were used as the carrier and coating material, respectively. The flow properties of Glibenclamide liquisolid compacts showed an acceptable flowability. The hardness, friability, weight variation and disintegration tests were within acceptable limits. The in vitro dissolution study confirmed enhanced drug release from liquisolid compacts compared with conventional and marketed tablet. XRPD studies showed complete inhibition of crystallinity in the Glibenclamide liquisolid compacts suggesting that the drug has been transformed into amorphous form having more solubility than the parent drug. The DSC study also supported the findings of XRPD analysis and confirmed the absence of any interaction between the drug and excipients used in the preparation of Glibenclamide liquisolid compacts. The liquisolid tablets having drug concentration of 5%w/w (LS-3) with Lf value of 0.270 and R value of 30, was chosen as best formulation among the twelve batches, in terms of faster disintegration time, superior dissolution profile and acceptable tablet properties. This research work has produced encouraging results in terms of increasing the in vitro dissolution of poorly soluble drugs such as glibenclamide using liquisolid technology and we expect a good correlation between the in vitro and in vivo performance of the formulations. The technique being simple and effective can also be extended to other poorly soluble drugs. The in vivo performance of the liquisolid compacts has to be studied using animal models to claim a complete success in the development of these formulations