Purpose: Plasticizers are commonly used in the preparation of amorphous solid dispersions (ASDs) with the main goal of aiding processability; however, to the best of our knowledge, the impact of plasticizers on drug release has not been explored. The goal of this study was to evaluate diverse plasticizers, including glycerol and citrate derivatives, as additives to increase the drug loading where good drug release could be achieved from copovidone (PVPVA)-based dispersions, focusing on high glass transition (T) drugs, atazanavir (ATZ) and ledipasvir (LED).
Methods: ASDs were prepared using the high T compounds, atazanavir (ATZ) and ledipasvir (LED), as model drugs.
Amorphous solid dispersion formulations (ASD) are increasingly being used as a formulation strategy to improve bioavailability of poorly soluble drugs. One of the limitations of ASDs, in particular for high glass transition temperature (T) compounds, is the drug loading threshold (termed the limit of congruency, LoC) below which rapid, complete and congruent release of drug and polymer is achieved. In this study, several ionic and non-ionic surfactants were added to atazanavir-copovidone ASDs with the main goal of increasing the limit of congruency.
View Article and Find Full Text PDFPurpose: Surfactants are increasingly being added to amorphous solid dispersion (ASDs) formulations to enhance processability and release performance. The goal of the current work was to investigate the impact of cationic, anionic and non-ionic surfactants on the rate and extent of clopidogrel (CPD) release from copovidone-based ASDs.
Methods: CPD release was evaluated for ASDs with different drug loadings using a surface normalized intrinsic dissolution apparatus.
Various techniques have been used to detect crystallization in amorphous solid dispersions (ASD). However, most of these techniques do not enable the detection of very low levels of crystallinity (<1%). The aim of the current study was to compare the sensitivity of second harmonic generation (SHG) microscopy with powder X-ray diffraction (XRPD) in detecting the presence of crystals in low drug loading amorphous solid dispersions.
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