Mechanistic Investigation of Pluronic® Based Nano-crystalline Drug-polymer Solid Dispersions

Abstract

The size of drug crystallites in the drug-polymer solid dispersions is independent of polymer topology, but is caused kinetically by a combined effect of nucleation rate and crystal growth rate. When drug-Pluronic solid dispersions crystallize at room temperature, that is close to the T(g1) of the systems, a fast nucleation rate and a relatively slow crystal growth rate of the drug synergistically produced small crystallite size. While the much higher T(g1) value of drug-PEG 8000 led to a slower nucleation rate and an even slower crystal growth rate at room temperature, therefore, small crystallite size and low drug crystallinity were observed. Results from BMS-A/Pluronic and BMS-B/Pluronic systems confirmed this kinetic theory.

Exceedingly Higher co-loading of Curcumin and Paclitaxel onto Polymer-functionalized Reduced Graphene Oxide for Highly Potent Synergistic Anticancer Treatment

“…Native G has a broad band appearing at 2θ = 15–30°, which is due to van der Waal’s interaction between the carbon network on the graphene sheets11. The semicrystalline polymer, P, however, has two peaks at the same region, starting at ≈19–36° 18. Upon functionalization, these peaks appeared in the GP composite with an overlap of G and P bands at 15–19°.…”

Characterisation of the thermal, spectroscopic and drug dissolution properties of mefenamic acid and polyoxyethylene–polyoxypropylene solid dispersions

“…At these sperulite interfaces, there is a lack of long‐range order and hence this amorphous character may accommodate MA as a molecular dispersion 26. However as the drug loading increases, the limited amorphous content of polymer (for Lutrol F68 this is 20%28 is unable to support further dispersion of MA at a molecular level resulting in crystallization of MA from the polymeric platform. The first evidence of small drug crystallites were observed at a drug loading of 15% along the sperulite interface (Fig.…”

Controlled Crystallization of the Lipophilic Drug Fenofibrate During Freeze-Drying: Elucidation of the Mechanism by In-Line Raman Spectroscopy

“…At a lower shelf temperature, the degree of supersaturation is higher, resulting in a higher nucleation rate (28). Since the formation of new nuclei and crystal growth are two competing processes (29), a higher nucleation rate results in more nuclei and consequently in smaller crystals. Thus, although the size of the interstitial spaces (controlled by the freezing rate) determines the maximum particle size, the crystal size is also determined by the balance between the formation of new nuclei and crystal growth (controlled by the shelf temperature).…”