Preparation, Characterization and in Vitro Dissolution Studies of Solid Systems of Valdecoxib with Chitosan

Abstract

In the present study, the solubilizing and amorphizing properties of Valdecoxib (a poorly water soluble anti inflammatory drug) with low molecular weight chitosan (a polymer), have been investigated. Binary systems of varying drug/polymer ratios were prepared using different techniques (physical mixing, co-grinding, kneading) and were tested for dissolution. Drug carrier interactions were investigated in both the liquid and solid state, by phase solubility analysis, differential scanning calorimetry, powder X-ray diffractrometry, FT-IR spectroscopy and scanning electron microscopy. The solubility of the drug increased with increasing polymer concentration showing A N type phase solubility diagram. Differential scanning calorimetry, powder X-ray diffractrometry and scanning electron microscopic studies of binary systems suggested generation of amorphous form of drug (in kneading and co ground mixtures). IR spectroscopy revealed the presence of hydrogen bonding in kneading and co ground mixtures. Drug dissolution was improved with increasing the polymer concentration in the mixture (KneadedϾco groundϾphysical mixture), which was attributed to the amorphonization and/or decreased drug crystallinity, size and polymer wetting effect. Enhanced dissolution combined with its direct compression feasibility and anti ulcerogenic action results in low molecular weight chitosan for developing fast release oral solid dosage forms of valdecoxib.

Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

“…The grinding method appears as a fast, highly efficient, convenient, and eco-friendly solvent-free solid mixtures formulation method, and the second method used, the kneading method, can be used as an industrially prepared solid binary system. Numerous reports indicate that chitosan can improve the dissolution rate and bioavailability of drugs with poor solubility [31][32][33][34][35][36][37][38]. Therefore, we compared the dissolution profile of pure CL in 1.0% sodium lauryl sulphate (SLS) to the dissolution profile of CL released from CL-CHA, CL-CHB, and CL-CHS mixtures obtained from different drug/polymer weight ratios.…”

Solid Dispersions of Chitosan Glutamate for the Local Delivery of Miconazole: Characterization and In Vitro Activity

“…9). On the other hand, chitosan is known to increase the dissolution proper-ties of poorly water soluble drugs [30,34,35], due to the reduced size of microparticles and the consequent increased surface area. MCN in fact showed a rapid released from both kinds of solid dispersion, independently on the drug-topolymer ratio (Fig.…”