الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Chapter One:
Development and characterization of a local mucoadhesive acyclovir gel formulationIn the present chapter, a mucoadhesive acyclovir suspension gel formulation (2%w/w) was successfully prepared utilizing Carbopol 934P (1%w/w) and HPMC (1%w/w) as the gel polymers. The prepared gel was assessed using different characterization methods, namely, content uniformity, pH, spreadability, viscosity, mucoadhesion, in-vitrodrug release and storage stability.
The mucoadhesive hydrogel was found to have desired durability of adhesion, erosion time, spreadability, pH and drug content uniformity.
The conventional gel exhibited non-Newtonian behavior and pseudo-plastic rheology.In vitrorelease experiments indicated prolonged and controlled release for 24 hours with an initial burst release.
Fitting release data into different kinetics models revealed that the gel formulation followed First-order release kinetics with non-Fickian diffusion and had similar release pattern as the reference formulation.
Stability studies revealed maintenance of gel stability when stored at 4°C up to six months. from the present chapter it can be concluded that the developed formulation is simple and easy to use for better patient compliance, having good mucoadhesive property and can release the drug at a controlled rate for prolonged time in the buccal cavity with improved performance compared to the commercial cream.
Chapter Two: Development andcharacterization of acyclovir-loaded lipid nanocapsules gel formulationsIn the current chapter, lipid nanocapsules (basic or modified formulae) containing acyclovir were prepared by the low energy phase inversion technique using generally “recognized as safe ingredients”, Labrafac®and Kolliphor®in order to improve the physicochemical properties of acyclovir.
Lipid nanocapsule dispersions were assessed using different techniquesto characterize colloidal properties, drug loading, and entrapment efficiency(EE %).
Transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) were also performed.The basic (LNC1) and Tween-containing (LNC3TmnL) LNCs were characterized by their small size, low PdI, barely negative zeta potential and goodentrapment efficiency. Modified LNCs (LNC1m5) were characterized by their larger size, relatively high PdI, negative zeta potential and good entrapment efficiency.
All the formulations exhibited fairly uniform drug content ensuring adequacy of preparationmethod of the LNCs. The TEM images revealed well dispersed spherical LNCs with smooth surface.
<DSC results suggested that ACV encapsulated in the LNCs was in the amorphous state.
<The lipid nanocapsules gels were prepared by the addition of HEC (3% w/w) to the lipid nanocapsules dispersions.
The LNC gels were assessed for pH, spreadability, viscosity, storage stability, mucoadhesion and in-vitrodrug release. No significant change in the colloidal properties of LNCs was observed upon the addition of polymer.
All gel formulations exhibited suitable pH value, good spreadability and good mucoadhesion. The mucoadhesion was high in case of ACV30-LNC1m5gel followed by ACV30-LNC1gel and then ACV30-LNC3TmnLgel.
In vitrorelease data indicated that all formulations exhibited sustained release up to 3hrs with First-order release kinetics except ACV30-LNC3TmnLgel which followed Higuchi model. The diffusion was found to be non-Fickian in all gel formulations except ACV30-LNC1gel which exhibited Fickian diffusion.
All gel formulations exhibited non-newtonian behavior with pseudoplastic rheology. LNC-based gels showed good storage stability at 4°C for 3 months.
In conclusion, ACV LNCs incorporated in gels represents a promising system for buccal 157administration of acyclovir.
The optimized LNC-gels were chosen for further ex vivopermeation in Chapter Three.
Chapter Three: Ex-vivopermeation study of acyclovir gel formulations using the chicken pouch membrane modelIn the present chapter the ex vivopermeation experiments were performed using QuixSep Micro Dializer and chicken buccal pouch.
<Three LNC gels and five controls including the conventional mucoadhesive gel and the commercial cream were included in the study.
<Ex vivopermeation study revealed sustained drug appearance in the receiving chamber up to 6 hours.
The cumulative percent of ACV permeated through chicken buccal pouch from ACV30-LNC1m5gel was the highest followed by ACV30-LNC3TmnLgel and then ACV30-LNC1gel compared to lower permeation obtained from conventional gel and commercial cream.
Significant enhancement of ACV deposition in chicken buccal pouch membrane was obtained after 6 hrs from ACV30-LNC1gel followed by ACV30-LNC1m5gel and ACV30-LNC3TmnLgel compared to lower deposition obtained from conventional gel and commercial cream.
<Strong in vitrorelease-ex vivopermeation correlations were obtained for formulae and controls.
<Inconclusion, lipid nanocapsules-based gels, developed in the present thesis possess promising in vitrophysicochemical characteristics and can successfully enhance acyclov