Solid oral controlled release formulations feature numerous clinical advantages for drug candidates with adequate solubility and dissolution rate. However, most new chemical entities exhibit poor water solubility, and hence are exempt from such benefits. Although combining drug amorphization with controlled release formulation is promising to elevate drug solubility, like other supersaturating systems, the problem of drug recrystallization has yet to be resolved, particularly within the dosage form.
View Article and Find Full Text PDFBioavailability of weakly basic drugs may be disrupted by dramatic pH changes or unexpected pH alterations in the gastrointestinal tract. Conventional organic acids or enteric coating polymers cannot address this problem adequately because they leach out or dissolve prematurely, especially during controlled release applications. Thus, a non-leachable, multifunctional terpolymer nanoparticle (TPN) made of cross-linked poly(methacrylic acid) (PMAA)-polysorbate 80-grafted-starch (PMAA-PS 80-g-St) was proposed to provide pH transition-independent release of a weakly basic drug, verapamil HCl (VER), by a rationally designed bilayer-coated controlled release bead formulation.
View Article and Find Full Text PDFPoor aqueous solubility is a major limiting factor during the development of BCS Class II drug candidates in a solid oral dosage form. Conventional amorphous solid dispersion (ASD) systems focus on maximizing the rate and extent of release by employing water-soluble polymeric crystallization inhibitors; however, they often encounter rapid supersaturation and solution-mediated phase transformation (SMPT). Therefore, in this work, a controlled release membrane was introduced onto ASD beads to mitigate the SMPT problem.
View Article and Find Full Text PDFWater-soluble polymers are often used as pore formers to tailor permeability of film-forming hydrophobic polymers on coated dosage forms. However, their addition to a coating formulation could significantly increase the viscosity thus making the coating process difficult. Moreover, the dissolution of pore formers after oral administration could compromise film integrity resulting in undesirable, inconsistent release profiles.
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