Noha Desouky Fayed
@tantauniversity.com
Faculty of pharmacy, Department of Pharmaceutical technology
Faculty of Pharmacy Tanta University
RESEARCH, TEACHING, or OTHER INTERESTS
Biotechnology
Scopus Publications
Scopus Publications
Noha D. Fayed, Mona F. Arafa, Ebtesam A. Essa, and Gamal M. El Maghraby
Elsevier BV
Noha D. Fayed, Ebtesam A. Essa, and Gamal M. El Maghraby
Informa UK Limited
Abstract Lopinavir is effective in treatment of HIV infection but experiences low oral bioavailability due to poor solubility, pre-systemic metabolism, and P-gp intestinal efflux. Co-processing with menthol enhanced its dissolution and intestinal permeability. Niosomes comprising Span 60, cholesterol, and poloxamer 407 were formulated in absence and presence of menthol. These were evaluated for size, morphology, entrapment efficiency (EE%), lopinavir release, and intestinal absorption. The later employed in situ rabbit intestinal absorption model. Niosomes were spherical with vesicle size of 140.2 ± 23 and 148.2 ± 27 nm for standard and menthol containing niosomes, respectively. The EE% values were 94.4% and 96.3% for both formulations, respectively. Niosomes underwent slow release during the time course of absorption with menthol hastening lopinavir release, but the release did not exceed 9%. Niosmoal encapsulation enhanced lopinavir intestinal absorption compared with drug solution. This was reflected from the fraction absorbed from duodenum, which was 24.15%, 73.09%, and 83.23% for solution, standard niosomes and menthol containing vesicles, respectively. These values were 34.32%, 80.8%, and 86.56% for the same formulations in case of jejuno-ileum. Lopinavir absorption from niosomes did not depend on release supporting intact vesicle absorption. The study introduced menthol containing niosomes as carriers for enhanced lopinavir intestinal absorption. Graphical Abstract
Noha D. Fayed, Ahmed E. Goda, Ebtesam A. Essa, and Gamal M. El Maghraby
Elsevier BV
Noha Fayed, Mohamed Osman, and Gamal Maghraby
Journal of Applied Pharmaceutical Science
The objective of this work was to improve the dissolution rate of candesartan cilexitil, a poorly water soluble prodrug and to reduce its premature degradation in the intestinal lumen. Binary and ternary solid dispersions (SD) of the drug with Pluronic F68, Polyvinyl pyrrolidone (PVP), Hydroxypropyl Methylcellulose (HPMC) and Tween 80 were prepared using the solvent evaporation method. The dissolution rate of the drug was monitored and the prepared SD systems were characterized using thermal analysis and Fourier transform infrared (FTIR) spectroscopy. The stability of candesartan in extracted rabbit intestinal fluids was monitored. This was conducted in absence and presence of tested excipients. SD of the drug with PVP resulted in significant enhancement in the dissolution rate of drug even at the lowest drug to polymer weight ratio. Similarly, SD with HPMC showed enhanced dissolution rate. SD with Pluronic F68 showed promising dissolution enhancement but this was recorded at higher polymer concentrations. Formulation of ternary SD of the drug and PVP with either Pluronic or Tween 80 resulted in rapid drug dissolution. The enhanced dissolution was mainly due to amorphousization of the drug with possible contribution to the micelle formation as reflected from thermal analysis. Incubation of pure candesartan in intestinal fluid resulted in rapid degradation of the drug. This degradation was not affected by 0.1% Pluronic. In presence of Tween 80 the rate of drug degradation was reduced significantly with the efficacy of Tween 80 depending on its concentration. The study developed a system for enhanced dissolution rate of candesartan with better stability in the intestinal lumen.