| Publication Type |
Journal Article |
| Title |
Unexpected solvent impact in the crystallinity of praziquantel/poly (vinylpyrrolidone) formulations. A solubility, DSC and solid-state NMR study |
| Authors |
Emanuel D. Costa Josefina Priotti Silvina Orlandi Dario Leonardi Maria C. Lamas Teresa G. Nunes H. P. Diogo Claudio J. Salomon M J Ferreira |
| Groups |
BioMol |
| Journal |
INTERNATIONAL JOURNAL OF PHARMACEUTICS |
| Year |
2016 |
| Month |
September |
| Volume |
511 |
| Number |
2 |
| Pages |
983-993 |
| Abstract |
The saturation solubility of PVP:PZQ physical mixtures (PMs) and solid dispersions (SDs) prepared from ethanol (E/E) or ethanol/water (E/W) by the solvent evaporation method at 1:1, 2:1 and 3:1 ratio (w/w) was determined. The presence of PVP improves the solubility of PZQ(0.31 +/- 0.01 mg/mL). A maximum of 1.29 +/- 0.03 mg/mL of PZQ in solution was achieved for the 3:1 SD (E/E). The amount of PZQ in solution depends on the amount of polymer and on the preparation method. Solid-state NMR (ssNMR) and DSC were used to understand this behavior. Results show that PMs are a mixture of crystalline PZQ with the polymer, while SDs show different degrees of drug amorphization depending on the solvent used. For E/W SDs, PZQ exists in amorphous and crystalline states, with no clear correlation between the amount of crystalline PZQ and the amount of PVP. For E/E SDs, formulations with a higher percentage of PZQ are amorphous with the components miscible in domains larger than 3 nm (H-1 ssNMR relaxation measurements). Albeit its higher saturation solubility, the 3:1 E/E PVP:PZQ sample has a significant crystalline content, probably due to the water introduced by the polymer. High PVP content and small crystal size account for this result. (C) 2016 Elsevier B.V. All rights reserved. |
| DOI |
http://dx.doi.org/10.1016/j.ijpharm.2016.08.009 |
| ISBN |
|
| Publisher |
ELSEVIER SCIENCE BV |
| Book Title |
|
| ISSN |
0378-5173 |
| EISSN |
1873-3476 |
| Conference Name |
|
| Bibtex ID |
ISI:000383810500029 |
| Observations |
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