New Mucoadhesive Chitosan Film for Ophthalmic Drug Delivery of Timolol Maleate: In Vivo Evaluation (original) (raw)
Related papers
Chitosan-Based In Situ Gels for Ocular Delivery of Therapeutics: A State-of-the-Art Review
Marine Drugs, 2018
Ocular in situ gels are a promising alternative to overcome drawbacks of conventional eye drops because they associate the advantages of solutions such as accuracy and reproducibility of dosing, or ease of administration with prolonged contact time of ointments. Chitosan is a natural polymer suitable for use in ophthalmic formulations due to its biocompatibility, biodegradability, mucoadhesive character, antibacterial and antifungal properties, permeation enhancement and corneal wound healing effects. The combination of chitosan, pH-sensitive polymer, with other stimuli-responsive polymers leads to increased mechanical strength of formulations and an improved therapeutic effect due to prolonged ocular contact time. This review describes in situ gelling systems resulting from the association of chitosan with various stimuli-responsive polymers with emphasis on the mechanism of gel formation and application in ophthalmology. It also comprises the main techniques for evaluation of chit...
Chitosan and its Derivatives for Ocular Delivery Formulations: Recent Advances and Developments
Polymers
Chitosan (CS) is a hemi-synthetic cationic linear polysaccharide produced by the deacetylation of chitin. CS is non-toxic, highly biocompatible, and biodegradable, and it has a low immunogenicity. Additionally, CS has inherent antibacterial properties and a mucoadhesive character and can disrupt epithelial tight junctions, thus acting as a permeability enhancer. As such, CS and its derivatives are well-suited for the challenging field of ocular drug delivery. In the present review article, we will discuss the properties of CS that contribute to its successful application in ocular delivery before reviewing the latest advances in the use of CS for the development of novel ophthalmic delivery systems. Colloidal nanocarriers (nanoparticles, micelles, liposomes) will be presented, followed by CS gels and lenses and ocular inserts. Finally, instances of CS coatings, aiming at conferring mucoadhesiveness to other matrixes, will be presented.
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2020
The use of chitosan as a pharmaceutical excipient in the ocular field is already established. Nevertheless, some aspects related to its ocular administration, such as sterilization and excipient's pharmacokinetics, remain unclear. So, in this study, we evaluated those two relevant aspects, related to chitosan administration in eye. We used chitosan‐based ocular inserts (CI) as formulation model. CI were produced by solvent/casting method and sterilized by saturated steam. Sterilization was confirmed by direct inoculation of inserts in suitable microbiological growth media. Physicochemical characterization of inserts before and after sterilization was performed. Results suggested that, although steam sterilization changed the arrangement of the matrix, the heat and the humidity did not modify the structure of the main polymeric chain. Pharmacokinetics of CI radiolabeled with technetium‐99m (99mTc) was assessed by scintigraphic images and ex vivo biodistribution study, after ocula...
Design and Evaluation of Modified Chitosan Based in Situ Gel for Ocular Drug Delivery
International Journal of Pharmacy and Pharmaceutical Sciences
Objective: The object of the present study was to formulate and evaluate in-situ gel of modified chitosan by using temperature triggered method to improve bioavailability.Methods: Modified chitosan-based moxifloxacin HCl was prepared by cold method. polaxomer 407 adding in distilled water and this solution kept in the refrigerator. Modified chitosan and moxifloxacin HCl was dissolved separately in distilled water and added to the polymeric solution with continuous stirring until thoroughly mixed. Prepared formulation was evaluated for drug content, gelling capacity, rheological study, in vitro drug release behavior, measurement of phase change temperature, antibacterial study, release kinetics, statistical analysis.Results: The prepared formulations were evaluated for their, drug content, gelation temperature, in vitro drug release studies, rheological study and release kinetics. All batches of in situ formulations had satisfactory pH ranging from 6.2±0.2, drug content between 98.8±...
Polymers, 2018
The main inconvenience of conventional eye drops is the rapid washout of the drugs due to nasolacrimal drainage or ophthalmic barriers. The ocular drug bioavailability can be improved by either prolonging retention time in the cul-de-sac or by increasing the ocular permeability. The focus of this review is to highlight some chitosan-based drug delivery approaches that proved to have good clinical efficacy and high potential for use in ophthalmology. They are exemplified by recent studies exploring in-depth the techniques and mechanisms in order to improve ocular bioavailability of the active substances. Used alone or in combination with other compounds with synergistic action, chitosan enables ocular retention time and corneal permeability. Associated with other stimuli-responsive polymers, it enhances the mechanical strength of the gels. Chitosan and its derivatives increase drug permeability through the cornea by temporarily opening tight junctions between epithelial cells. Differ...
Asian Journal of Pharmaceutics, 2020
Aim: The aim of the present research work is to use our previously modified chitosan in formulation development and optimization of ocular insert. Materials and Methods: Ocular insert was made from an aqueous dispersion of ofloxacin, polyvinyl alcohol (PVA), modified chitosan, sodium alginate, and dibutyl phthalate by the solvent casting method. It was coated with Eudragit S100 and evaluated for drug-excipient interaction, physicochemical characteristics, and microbiological and in vitro release studies. In the present study, 32 full factorial designs were employed with the help of Design-Expert software to study the effect of independent variables, i.e., effects of PVA amount (X1) and modified chitosan amount (X2) on the dependent variables, i.e., % moisture absorption and mucoadhesion time. Results and Discussions: In Fourier transform infrared study, a major characteristic peak of ofloxacin was found in the entire coated ocular inserts, confirming the presence of the drug in the ...