Solid dispersion of acetaminophen and poly(ethylene oxide) prepared by hot-melt mixing

Determination of acetaminophen's solubility in poly(ethylene oxide) by rheological, thermal and microscopic methods

“…5, the critical turning point is around 10% for DSC and 5% for DMTA. The result is consistent with the findings by our group (Yang et al, 2010) that above 10% drug loading, APAP will recrystallize from PEO after the sample is cooled from the HME processing temperature to room temperature. Fig.…”

“…Our previous results (Yang et al, 2010) also show that APAP dissolves in molten PEO at high processing temperature, but recrystallizes after being cooled to room temperature when the drug loading is between 10 and 30 wt%. Therefore, it is expected that there will be a strong dependence of APAP's solubility on temperature, which also makes the system an interesting candidate for the current study.…”

“…The hydroxyl group of acetaminophen is a good proton donor and can form strong hydrogen bonds with the oxygen acceptor on the PEO chain (Shekunov et al, 1999(Shekunov et al, , 2007, which is capable of leading to a nonlinear relationship between T g and the composition. Strong intermolecular interaction is usually beneficial for miscibility and solid solution stabilization (Chokshi et al, 2008;Miyazaki et al, 2006;Taylor and Zografi, 1997), but the H-bonding in the current case does not seem to prevent APAP from recrystallizing at room temperature (Yang et al, 2010). According to Wen et al (2005Wen et al ( , 2008 the high flexibility of PEG and the high mobility of the function groups involved in the H-bonds is the reason why the crystallization of APAP cannot be inhibited.…”

“…Glass transition temperatures were determined using both DSC and DMTA methods. It should be mentioned that the system probably has not reached thermodynamic equilibrium after four weeks at room temperature, although the recrystallization does drop to an almost undetectable slow rate (Yang et al, 2010) by that time. Hence, the solubility obtained is apparent solubility, which may be higher than the thermodynamic solubility.…”

Development of a Sustained Release Solid Dispersion Using Swellable Polymer by Melting Method

“…The incorporation of poorly water-soluble drugs into SR carriers using solid dispersion (SD) technique can solve the above issues by enhancement of dissolution rate, solubility, oral absorption of water insoluble drugs as well as sustaining drug release with appropriate polymers (3). Advantages of polymers such as hydroxypropyl methycellulose and polyethylene oxide are hydrophilic and swellable properties which can be utilized in increasing dissolution rate (4)(5)(6)(7)(8)(9)(10)(11) and modulating drug release profiles (12)(13)(14)(15)(16). The application of these two polymer properties in one system could facilitate the design of a dual function drug delivery system by preparation of SD for dissolution enhancement and compression of matrix tablets for sustained release (3,17).…”