Development and Optimization of Liquid Crystalline Nanostructures for Enhanced Ocular Delivery / by Mohamed Ahmed Emad Abdellatif Elgendy Assistant Lecturer at Department of Pharmaceutics and Pharmaceutical Technology Faculty of Pharmacy, Future University in Egypt ; supervisors : Prof. Dr. Nahed Daoud Mortada Professor of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University, Prof. Dr. Mona Ibrahim Abdul Tawab Elassal Professor of Pharmaceutics and Pharmaceutical Technology Faculty of Pharmacy, Future University in Egypt, Prof. Dr. Rania Aziz Helmy Ishak Professor of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University, Dr. Mai Mansour Soliman Lecturer of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University.

supervisors : Prof. Dr. Nahed Daoud Mortada Professor of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University, Prof. Dr. Mona Ibrahim Abdul Tawab Elassal Professor of Pharmaceutics and Pharmaceutical Technology Faculty of Pharmacy, Future University in Egypt, Prof. Dr. Rania Aziz Helmy Ishak Professor of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University, Dr. Mai Mansour Soliman Lecturer of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University.

Thesis (Ph.D.)--Ain Shams University, Faculty of pharmacy, Department of Pharmaceutics and Industrial Pharmacy,2022.

Includes bibliographical references (pages 197- 231).

Liquid crystalline nanostructures (LCNs), for instance cubosomes, have been
widely used as a promising carrier for drug delivery through the last few years. To
date, the ophthalmic application of these platforms is not well explored, and the
effect of integrating penetration enhancers (PEs) into LCNs has not been
investigated yet. Cubosomes mainly prepared using Glyceryl monooleate (GMO) or
Phytantriol (PYT) as a lipid with the addition of Poloxamer 407 (P407) as a
stabilizer. The integration of new stabilizers other than P407 is still limited in
research. Thus, this thesis is divided into three chapters.
LCNs were prepared using hot emulsification method by coupling of novel
PEs at different amounts into GMO-based cubosomes for ocular administration. The
morphology of the formed LCNs was investigated using transmission electron
microscopy (TEM). The crystallinity and thermal behavior studies were also
conducted. The acceptable formulations exhibited relatively homogenous particle
nano-sizes ranging from 139.26 ± 3.68 to 590.56 ± 24.86 nm carrying negative
surface charges. TEM images, X-ray patterns and DSC thermograms demonstrated
the influential effect of PEs in developing altered crystalline structures. Hen’s egg
test-chorioallantoic membrane (HET-CAM), rabbit eye Draize test, and
histopathological examinations of ocular tissues confirmed the ocular compatibility
of optimized LCNs. The corneal distribution using confocal laser scanning
microscope (CLSM) proved the disseminated fluorescence intensity of LCNs
enriched with oleic acid, Captex® 8000 and Capmul® MCM as enhancers. Selected
LCNs showed good physical stability upon storage and lyophilization.
Moreover, D-optimal design was applied to investigate the optimal LCNs
composition for drug loading. A preliminary study was conducted to optimize the
key formulation components of LCNs; Phytantriol (PYT) in comparison to GMO as
lipids, and different stabilizers were compared to P407. This study aimed to set the
type and the amount range of each component to be used later in the experimental
design for optimization, where GMO, TPGS and Tween 80 were proven to be the
most suitable for fabrication of optimized LCNs loaded with the anti-glaucomic
drug, Travoprost (TRAVO). Optimum formulae were F-1-L and F-3-L both
composed of 25 mg GMO (lipid), 25 mg Tween 80 (stabilizer) and 25 mg of oleic
acid and Captex 8000 (PE), respectively. They showed PS of 216.20 ± 6.12 and
129.40 ± 11.73 nm with PDI values of 0.27 ± 0.03 and 0.34 ± 0.03, respectively. The
ZP values were -72.93 ± 1.97 and -17.55 ± 2.10 mV, and both formulae revealed
high EE % of 85.30 ± 4.29 and 82.54 ± 7.65%, respectively. Furthermore, they
showed the highest drug permeation profile during the ex-vivo studies.
The pharmacodynamic (PD) and pharmacokinetic (PK) studies conducted on
adult New Zealand White rabbits in addition to ocular tolerability and histological
examinations showed that, F-1-L has achieved its lowest IOP (15.6 mmHg) at 6 h
post-dose application and maintained its lowering effect for 48 h. On other hand, F3-L, showed the lowest IOP (13.9 mmHg) at 24 h after instillation and its effect
lasted for the 72 h. At last, Travatan® (the market product) showed its lowest IOP
(14.7 mm Hg) at 8 h and its effect was lasted for 36 h only. The LCN formula F-3-
L showed a significant higher Cmax of 1.80 ± 0.15 ng/ml (p<0.05), when compared
to 1.46 ± 0.06 and 1.42 ± 0.09 ng/ml obtained in case of F-1-L and Travatan®,
respectively. The highest median Tmax of 6 h attained by F-3-L confirmed the more
controlled drug permeation behavior than those achieved by Travatan® and F-1-L
recording 1 and 2 h, respectively. Furthermore, the chosen formulation F-3-L
showed significant higher AUC0-48, AUCinf and MRT of 62.77 ± 2.73 ng.h/ml,
406.69 ± 17.12 ng.h/ml and 23.18 ± 0.57 h in comparison to the respective data
obtained from F-1-L and Travatan® 43.02 ± 2.97 and 11.58 ± 0.23 ng.h/ml, 133.63
± 11.54 and 125.98 ± 8.54 ng.h/ml, 11.73 ± 0.22 and 11.58 ± 0.23 h. The
bioavailability of both formulae relative to the market product TRAVATAN® was
also calculated, as F-1-L showed a relative bioavailability of 106.1%, while F-3-L
showed a much higher value of 322.82% with respect to the market product. All the
tested LCNs did not show any signs of ocular damage or clinical abnormalities
compared to the control eye as observed. The current thesis described the successful
incorporation of a novel PE (Captex®8000) into conventional LCNs. Furthermore,
TRAVO loading in such liquid crystals stabilized with Tween 80 resulted in a safe
and effective ocular drug delivery system for glaucoma treatment. The prepared
LCNs demonstrated favorable penetration power throughout the corneal layer, as
well as good stability and high TRAVO entrapment efficiency. While instilling the
same drug dose, the bioavailability of TRAVO was increased three-folds when
delivered using LCNs relative to the market product Travatan®, confirming the
superiority of the tailored TRAVO-LCNs in the management of glaucoma.

Text in English, abstract in English and Arabic.