The Synthesis and Characterization of the Poly[N-vinylpyrrolidone-co-ethylidene-bis-3-(N-vinyl-2-pyrrolidone)] Hydrogel Matrix for Drug Delivery to the Gastrointestinal Tract

Summary Hydrogels based on copolymers of N-vinylpyrrolidone and ethylidene-bis-3-(N-vinyl-2-pyrrolidone) (EBVP) were prepared as polymer matrices for controlled release of high loads of hydrophilic compounds into the gastrointestinal tract. EBVP was synthesized and used as a crosslinking agent for the N-vinylpyrrolidone monomer. The polymerization mixtures, containing 65–80 wt.% of the model pharmacologically active compound, were polymerized to create cylindrical formulations. The release experiments were carried out under conditions corresponding to the digestive tract. Various compositions of hydrogel matrices were tested to reveal the influence of the active compound content and the crosslinking ratio on the release kinetics. Processes such as hydrogel swelling, dissolution and formulation disintegration were evaluated. The results obtained show that the system offers many possibilities to control the drug release to meet various medicinal requirements.