Thermodynamically stable amorphous drug dispersions in amorphous hydrophilic polymers engineered by hot melt extrusion

Characterisation and modelling of the thermorheological properties of pharmaceutical polymers and their blends using capillary rheometry: Implications for hot melt processing of dosage forms

“…In line with previous reports (Kararli et al, 1990;Prodduturi et al, 2004), a glass transition was not detected for HPC in this study using DMTA (Table 1). However, glass transition temperatures of HPC containing 5, 10 and 20% w/w quinine base and 5 and 10% w/w quinine hydrochloride were observed, were statistically similar and ranged between 43.1 ± 2.2 and 46.2 ± 3.1 o C. Accordingly it may be concluded that quinine (when used as the base or hydrochloride) did not act as a plasticiser for HPC, either in the heated or cooled states (Nair et al, 2001;Wu and McGinity, 1999)., The observed glass transition temperatures for the quinine base-containing platforms (5-20% w/w) and quinine hydrochloride platforms (5, 10% w/w) were statistically similar and were in accordance with a previous publication (Jones et al, 2015).…”

“…These observations may be explained by consideration of the physical state of quinine base within the polymer blends and within the individual polymer platforms and the viscosities of the various polymer blends. In the presence of Eudragit E100 quinine base acts as a plasticiser and lowered the glass transition temperature of this polymer whereas quinine base exists as an amorphous dispersion within HPC, the latter observation confirming the findings of a previous study that demonstrated the presence of amorphous quinine base within HPC hot melt extrudates (Jones et al, 2015). Quinine base lowered the glass transition temperature of Eudragit E100 within the different polymer blends, however within the 1:3 E100: HPC blend the effects of the 5% and 20% quinine base loadings were similar.…”

Thermal Behavior of Polymers in Solid-State

“…Applied ester derivatives from cellulose, namely hydroxy propyl cellulose (HPC), increased the stability of quinine. However, the study did not report the thermal properties of HPC (44). The results obtained from HME of each quinine and quinine hydrochloride using HPC as polymers produced different Tg.…”

“…Therefore, many cellulose modifications have been made physically or chemically to improve cellulose deficiencies, one of which is making esters derivatives (43). Something that needs to be considered when applying cellulose as a polymer in active substances is that thermal stability depends on molecular weight because cellulose is complex; the level of cellulose used; and environmental humidity (44).…”

Implementation of transmission NIR as a PAT tool for monitoring drug transformation during HME processing

“…For example, HME is solvent free, a wide range of excipients can be processed, and it is cost effective and can be easily scaled-up with high throughput and operated in continuous mode [6]. HME has been utilised to enhance the dissolution rate of APIs by preparing solid dispersions [7,8] where the drug is molecularly dispersed in the polymer matrix which leads to improved bioavailability [9]. Repka et al utilised HME to prepare bioadhesive films with increased dissolution rates of poorly water-soluble drugs by exploring the influence of processing parameters [10][11][12].…”