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Improved corneal bioavailability of ofloxacin: biodegradable microsphere-loaded ion-activated in situ gel delivery system.

Sayed EG, Hussein AK, Khaled KA, Ahmed OA - Drug Des Devel Ther (2015)

Bottom Line: The prepared OFX formulations were then investigated in vivo compared with commercially available OFX eyedrops.Incorporation of OFX-loaded microspheres in Gelrite solution (0.4% w/v) significantly altered the release profiles of OFX-loaded microspheres in situ gel formula compared with the corresponding OFX gels and OFX microspheres.In vivo results in rabbits showed that OFX-loaded microspheres in situ gel formula improved the relative bioavailability by 11.7-fold compared with the commercially available OFX eyedrops.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Minia University, Minia, Egypt.

ABSTRACT
The aim of the study was to improve corneal penetration and bioavailability of ofloxacin (OFX) eye preparations. OFX was incorporated in poly (lactide-co-glycolide) as biodegradable microspheres using oil in oil emulsion solvent evaporation technique. The prepared OFX microspheres were then incorporated in Gelrite(®) in situ gel preparation. In addition, OFX Gelrite-based in situ gel formulations were prepared. OFX formulations were characterized for gelling capacity, viscosity, and rheological properties. Release studies for OFX microspheres, OFX in situ gel, and OFX-loaded microspheres in situ gel formulations were carried out to investigate release characteristics of the drug. The prepared OFX formulations were then investigated in vivo compared with commercially available OFX eyedrops. Results showed that the optimum Gelrite concentration was at 0.4%-0.7% w/v; the prepared formulations were viscous liquid transformed into a pourable gel immediately after the addition of simulated tear fluid with a gelling factor of 27-35. Incorporation of OFX-loaded microspheres in Gelrite solution (0.4% w/v) significantly altered the release profiles of OFX-loaded microspheres in situ gel formula compared with the corresponding OFX gels and OFX microspheres. In vivo results in rabbits showed that OFX-loaded microspheres in situ gel formula improved the relative bioavailability by 11.7-fold compared with the commercially available OFX eyedrops. In addition, the longer duration of action of OFX-loaded microspheres in situ gel formula preparations is thought to avoid frequent instillations, which improves patient tolerability and compliance.

No MeSH data available.


Related in: MedlinePlus

Effect of different Gelrite concentrations on the release of OFX from in situ gels.Note: As a result of overlapping, error bars were omitted for clarity.Abbreviation: OFX, ofloxacin.
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f4-dddt-9-1427: Effect of different Gelrite concentrations on the release of OFX from in situ gels.Note: As a result of overlapping, error bars were omitted for clarity.Abbreviation: OFX, ofloxacin.

Mentions: Figure 4 shows the cumulative percent of OFX released as a function of time for various Gelrite formulations. All the investigated formulations showed a linear release profile for the first 12 hours of the study. The in situ gel formula with Gelrite concentration of 0.1% w/v released more than 80% of the drug after 12 hours of the experiment. The release of OFX, after 12 hours, from Gelrite in situ gel formulation was decreased with the increase in Gelrite concentration; the Gelrite in situ gel formula with 0.6% w/v Gelrite showed about 54% cumulative OFX release after 12 hours (Figure 4). The decrease in the release of OFX from in situ gel formulations is attributed to the increase of the polymer concentration, as by increasing the polymer concentration, a denser polymeric chain structure is produced. Thus, the diffusion of OFX through the denser formulations is reduced. In addition, the entrance of water into these formulations was reduced; thus, the rates of both dissolution and erosion were reduced.


Improved corneal bioavailability of ofloxacin: biodegradable microsphere-loaded ion-activated in situ gel delivery system.

Sayed EG, Hussein AK, Khaled KA, Ahmed OA - Drug Des Devel Ther (2015)

Effect of different Gelrite concentrations on the release of OFX from in situ gels.Note: As a result of overlapping, error bars were omitted for clarity.Abbreviation: OFX, ofloxacin.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4362657&req=5

f4-dddt-9-1427: Effect of different Gelrite concentrations on the release of OFX from in situ gels.Note: As a result of overlapping, error bars were omitted for clarity.Abbreviation: OFX, ofloxacin.
Mentions: Figure 4 shows the cumulative percent of OFX released as a function of time for various Gelrite formulations. All the investigated formulations showed a linear release profile for the first 12 hours of the study. The in situ gel formula with Gelrite concentration of 0.1% w/v released more than 80% of the drug after 12 hours of the experiment. The release of OFX, after 12 hours, from Gelrite in situ gel formulation was decreased with the increase in Gelrite concentration; the Gelrite in situ gel formula with 0.6% w/v Gelrite showed about 54% cumulative OFX release after 12 hours (Figure 4). The decrease in the release of OFX from in situ gel formulations is attributed to the increase of the polymer concentration, as by increasing the polymer concentration, a denser polymeric chain structure is produced. Thus, the diffusion of OFX through the denser formulations is reduced. In addition, the entrance of water into these formulations was reduced; thus, the rates of both dissolution and erosion were reduced.

Bottom Line: The prepared OFX formulations were then investigated in vivo compared with commercially available OFX eyedrops.Incorporation of OFX-loaded microspheres in Gelrite solution (0.4% w/v) significantly altered the release profiles of OFX-loaded microspheres in situ gel formula compared with the corresponding OFX gels and OFX microspheres.In vivo results in rabbits showed that OFX-loaded microspheres in situ gel formula improved the relative bioavailability by 11.7-fold compared with the commercially available OFX eyedrops.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Minia University, Minia, Egypt.

ABSTRACT
The aim of the study was to improve corneal penetration and bioavailability of ofloxacin (OFX) eye preparations. OFX was incorporated in poly (lactide-co-glycolide) as biodegradable microspheres using oil in oil emulsion solvent evaporation technique. The prepared OFX microspheres were then incorporated in Gelrite(®) in situ gel preparation. In addition, OFX Gelrite-based in situ gel formulations were prepared. OFX formulations were characterized for gelling capacity, viscosity, and rheological properties. Release studies for OFX microspheres, OFX in situ gel, and OFX-loaded microspheres in situ gel formulations were carried out to investigate release characteristics of the drug. The prepared OFX formulations were then investigated in vivo compared with commercially available OFX eyedrops. Results showed that the optimum Gelrite concentration was at 0.4%-0.7% w/v; the prepared formulations were viscous liquid transformed into a pourable gel immediately after the addition of simulated tear fluid with a gelling factor of 27-35. Incorporation of OFX-loaded microspheres in Gelrite solution (0.4% w/v) significantly altered the release profiles of OFX-loaded microspheres in situ gel formula compared with the corresponding OFX gels and OFX microspheres. In vivo results in rabbits showed that OFX-loaded microspheres in situ gel formula improved the relative bioavailability by 11.7-fold compared with the commercially available OFX eyedrops. In addition, the longer duration of action of OFX-loaded microspheres in situ gel formula preparations is thought to avoid frequent instillations, which improves patient tolerability and compliance.

No MeSH data available.


Related in: MedlinePlus