Formulation of active pharmaceutical ingredients (API) in high-energy amorphous forms is a common strategy to enhance solubility, dissolution rate and, consequently, oral bioavailability of poorly water-soluble drugs. Amorphous APIs are, however, susceptible to recrystallization and, therefore, there is a need to physically stabilize them as solid dispersions in polymeric carriers. Hot melt extrusion has in recent years gained wide acceptance as a method of choice for the preparation of solid dispersions. There is a potential that the API, the polymer or both may degrade if excessively high temperature is needed in the melt extrusion process, especially when the melting point of the API is high. This report details a novel method where the API was first converted to an amorphous form by solvent evaporation and then melt-extruded with a suitable polymer at a drug load of at least 20% w/w. By this means, melt extrusion could be performed much below the melting temperature of the drug substance. Since the glass transition temperature of the amorphous drug was lower than that of the polymer used, the drug substance itself served as the plasticizer for the polymer. The addition of surfactants in the matrix enhanced dispersion and subsequent dissolution of the drug in aqueous media. The amorphous melt extrusion formulations showed higher bioavailability than formulations containing the crystalline API. There was no conversion of amorphous solid to its crystalline form during accelerated stability testing of dosage forms.
Cryptosporidiosis
is a leading cause of moderate-to-severe diarrhea
in low- and middle-income countries, responsible for high mortality
in children younger than two years of age, and it is also strongly
associated with childhood malnutrition and growth stunting. There
is no vaccine for cryptosporidiosis and existing therapeutic options
are suboptimal to prevent morbidity and mortality in young children.
Recently, novel therapeutic agents have been discovered through high-throughput
phenotypic and target-based screening strategies, repurposing malaria
hits, etc., and these agents have a promising preclinical in vitro
and in vivo anti-
Cryptosporidium
efficacy. One key
step in bringing safe and effective new therapies to young vulnerable
children is the establishment of some prospect of direct benefit before
initiating pediatric clinical studies. A
Cryptosporidium
controlled human infection model (CHIM) in healthy adult volunteers
can be a robust clinical proof of concept model for evaluating novel
therapeutics. CHIM could potentially accelerate the development path
to pediatric studies by establishing the safety of a proposed pediatric
dosing regimen and documenting preliminary efficacy in adults. We
present, here, perspectives regarding the opportunities and perceived
challenges with the
Cryptosporidium
human challenge
model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.