Comparative study on different techniques for enhancing the solubility and bioavailability of indomethacin

ABSTRACT

Indomethacin [INDO] is a non steroidal anti-inflammatory drug. This study was designed to investigate the possible enhancing availability of poorly soluble, highly permeable [class II] drugs like indomethacin, via its formulation in a highly soluble form compared to pure drug, using solid dispersion, solvent deposition, and powder solution [liquisolid] formation techniques. The dissolution rates of the drug from the formulae prepared by different techniques are significantly more rapid than from pure drug and are almost higher than the commercially available capsules [Indocid]. The differential scanning colorimetry [DSC] study was done to investigate possible interactions between INDO and the used carriers. The stability study of INDO formulate was done at 40§C and 75% relative humidity [RH] for six months. The storage testing showed that all systems were stable and showed no significant difference than the non stressed one. The liquisolid formula F4-LS, with enhanced dissolution rate and acceptable flowability was subjected to bioavailability study and was compared with commercially available capsules [Indocid]. The results of the pharmacokinetic parameters of the tested formula, were treated statistically, using unpaired t test at P<0.05. The results showed shorter t[max], higher AUC[0-24], and AUC[0-[infinity]]. The drug in this formula has also a good relative bioavailability. Thus the liquisolid capsules can be promising alternative for the formulation of water insoluble drugs, such as INDO, into rapid release forms. The enhanced oral bioavailability may be due to the increased wetting properties and the solubility of drug in the used liquid vehicle used