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This article investigates enhancement of the dissolution profile of valdecoxib using solid dispersion with PVP. The article also describes the preparation of fast-dissolving tablets of valdecoxib by using a high amount of superdisintegrants. A phase solubility method was used to evaluate the effect of various water-soluble polymers on aqueous solubility of valdecoxib. Polyvinyl pyrrolidone (PVP K-30) was selected and solid dispersions were prepared by the method of kneading. Dissolution studies using the USP paddle method were performed for solid dispersions of valdecoxib. Infrared (IR) spectroscopy, differential scanning calorimetry (DSC), and x-ray diffractometry (XRD) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. Tablets were formulated containing solid dispersion products and compared with commercial products. IR spectroscopy, XRD, and DSC showed no change in the crystal structure of valdecoxib. Dissolution of valdecoxib improved significantly in solid dispersion products (< 85% in 5 minutes). Tablets containing solid dispersion exhibited better dissolution profile than commercial tablets. Thus, the solid dispersion technique can be successfully used for improvement of dissolution of valdecoxib.

Angiogenesis supports normal physiology as well as contributing to the progression of various diseases including cancer. Determination of the key role of angiogenesis in cancer has led to much optimism for the development of targeted drugs without cytotoxic side-effects. Currently, research in angiogenesis therapy is robust, with the discovery of a growing number of pro-and antiangiogenic molecules. More time, however, is required to be able to elucidate the complex interactions among these molecules, how they affect vasculature and their functions in different environments. As we learn more about the molecular mechanisms of angiogenesis, a number of effective methods to treat cancer and other diseases will be developed.

The aim of this work was to study the inclusion behaviour of a poorly water-soluble bioflavonoid, quercetin, towards sulfobutyl ether-7beta-cyclodextrin. It also involves angiogenesis inhibition in-vivo in addition to in-vitro human cancer cell growth inhibition study of quercetin and its cyclodextrin complex. Drug-cyclodextrin solid inclusion complexes were prepared and characterized in solution and in the solid state. An in-vitro anti-proliferation study using plain drug and its solubilized form was carried out on human cancer cell lines of different origin. Further, an in-vivo tumour growth inhibition study was carried out using a mouse melanoma model. Histological sections of tumours were examined for the evaluation of tumour microvessel density. Significant enhancement of the solubility and dissolution rate of the quercetin, which occurred after complexation, might be attributed to the decrease in crystallinity of drug. SBE7betaCD complex of quercetin was more potent for inhibiting cell proliferation in human erythroleukaemia and cervix cancer cells. Decreased tumour microvessel density in mouse melanoma after oral quercetin administration led to diminished tumour cell proliferation. Quercetin-SBE7betaCD complex showed significantly improved anti-cancer activity at much lower concentration than the plain drug, providing evidence for dose reduction without affecting therapeutic efficacy when using cyclodextrin carriers.