High-Energy Ball Milling as Green Process To Vitrify Tadalafil and Improve Bioavailability.
In this study, the suitability of high-energy ball milling was investigated with the aim to vitrify tadalafil (TD) and improve its bioavailability. To achieve this goal, pure TD as well as binary mixtures composed of the drug and Soluplus (SL) were coprocessed by high-energy ball milling. Modulated differential scanning calorimetry (MDSC) and X-ray powder diffraction (XRD) demonstrated that after such coprocessing, the crystalline form of TD was transformed into an amorphous form. The presence of a single glass transition (Tg) for all the comilled formulations indicated that TD was dispersed into SL at the molecular level, forming amorphous molecular alloys, regardless of the drug concentration. The high values of Tgdetermined for amorphous formulations, ranging from 70 to 147 °C, foreshow their high stability during storage at room temperature, which was verified by XRD and MDSC studies. The stabilizing effect of SL on the amorphous form of TD in comilled formulations was confirmed. Dissolution tests showed immediate drug release with sustained supersaturation in either simulated gastric fluid of pH 1.2 or in phosphate buffer of pH 7.2. The beneficial effect of both amorphization and coamorphization on the bioavailability of TD was found. In comparison to aqueous suspension, the relative bioavailability of TD was only 11% for its crystalline form and 53% for the crystalline physical mixture, whereas the bioavailability of milled amorphous TD and the comilled solid dispersion was 128% and 289%, respectively. Thus, the results provide evidence that not only the presence of polymeric surfactant but also the vitrification of TD is necessary to improve bioavailability.
Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, Jagiellonian University Collegium Medicum , 9 Medyczna Street, Cracow, Poland.
Anna
A
Krupa
UMET, Unité Matériaux et Transformations, CNRS, INRA, University of Lille , F 59 000 Lille, France.
Marc
M
Descamps
UMET, Unité Matériaux et Transformations, CNRS, INRA, University of Lille , F 59 000 Lille, France.
Jean-François
JF
Willart
Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Collegium Medicum , 9 Medyczna Street, Cracow, Poland.
Beata
B
Strach
Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Collegium Medicum , 9 Medyczna Street, Cracow, Poland.
Elżbieta
E
Wyska
Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, Jagiellonian University Collegium Medicum , 9 Medyczna Street, Cracow, Poland.
Renata
R
Jachowicz
UMET, Unité Matériaux et Transformations, CNRS, INRA, University of Lille , F 59 000 Lille, France.
Florence
F
Danède
D001682:Biological Availability; D002152:Calorimetry, Differential Scanning; D008855:Microscopy, Electron, Scanning; D000068581:Tadalafil / Q000737:chemistry*; D014961:X-Ray Diffraction
D000068581:Tadalafil
bioavailability improvement; comilling; dissolution enhancement; solid dispersion; tadalafil; vitrification