Microenvironmental pH Control and Mixed Polymer Approaches to Optimise Drug Delivery with Hydrophilic Matrix Tablets

Semisolid-filled Capsules of Carvedilol for Improving Dissolution Behaviour

“…The saturation solubility of CV in distilled water and in phosphate buffer (pH 7.4) was found to be 0.00022±0.0015 and 0.0058±0.0013 mg/ml, respectively. In basic pH, the solubility of CV is poor owing to its basic nature [27] . As it remains in the unionized form in distilled water and in pH 7.4 phosphate buffer, it dissolves at a lower rate in these media.…”

Effects of radio frequency power on the microstructures and properties of plasma polymerized polypyrrole thin films

“…A higher hydrophobicity can be a preferable choice for elapsed chemical release in pH neutral microenvironment [58]. In addition, higher deposition rate, thicker and denser with more retaining carbon rings are also important to keep films intact during long time immersion in DI water.…”

Effect of gastrointestinal transit on micro-environmental pH inside HPMC matrix tablets – in vitro study

“…Most of the available active pharmaceutical ingredients (API) are either weak acids, bases or their salts with dissociation constants within or near the range of the physiological pH values in the GIT. This results in their pH-dependent solubility, which affects the drug absorption process (Timmins et al, 2014). Oral dosage forms are exposed to both acidic and neutral conditions while passing along the digestive tract.…”

“…In the case of hydrophilic matrix systems, drug release is a complex interplay between matrix erosion and drug diffusion, with both processes depending on the luminal pH conditions at the absorption site. (Timmins et al, 2014;Siepmann and Peppas, 2001). The solubility of ionizing compounds (i.e.…”

“…Although the concept of pH M is well known and has been extensively studied, there is no well-established technique available to measure it and correlate the results to in vivo findings. The pH evaluation in the solid dosage forms relies largely on indirect measurement of the pH M , such as determination of the pH M using a pH meter or indicator dye media, using confocal microscopy, nuclear magnetic resonance (NMR) or electron paramagnetic resonance (EPR) (Timmins et al, 2014;Badawy and Hussain, 2007). Listed methods, however, have many shortcomings.…”