ABSTRACT
Conventional eye drops show relatively low bioavailability due to poor precorneal contact time. In situ hydrogels are of great importance in providing sustained ocular drug delivery. By exhibiting elastic properties they resist ocular drainage of the drug leading to longer contact times. In the present study an in situ gelling thermoreversible mucoadhesive gel was formulated of an antibacterial agent, Moxifloxacin HCl using a combination of poloxamer 407 and poloxamer 188 with different mucoadhesive polymers such as Xanthan gum and Sodium alginate with a view to increase gel strength and bioadhesion force and thereby increased precorneal contact time and bioavailability of the drug. Formulations were evaluated for physical parameters like clarity, pH, spreadability, drug content, gelation temperature, gel strength, bioadhesion force and in vitro drug release study. Formulations were found transparent, uniform in consistency and had good spreadability within a pH range of 6.8 to 7.4. A satisfactory bioadhesion (3298 to 4130 Dyne/cm2) on the sheeps corneal surface and good gel strength (95 to 128 sec) was also observed. As the concentration of mucoadhesive polymers in the gel formulation increased, the rate of drug release decreased. The order of drug release was in order: Xanthan gum > Sodium alginate. It was concluded that a thermoreversible in situ gel of Moxifloxacin HCl can be formulated by combining with mucoadhesive polymers and used effectively as safe and sustained ocular drug delivery. This combination provided greater bioadhesion force and gel strength as compared to the thermoreversible polymers i.e., poloxamer 407 (PF 127) or 188 (PF 68) when used alone.
Subject(s)
Anti-Bacterial Agents/chemistry , Drug Carriers , Fluoroquinolones/chemistry , Poloxamer/chemistry , Temperature , Adhesiveness , Administration, Ophthalmic , Alginates/chemistry , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/metabolism , Chemistry, Pharmaceutical , Cornea/metabolism , Delayed-Action Preparations , Fluoroquinolones/administration & dosage , Fluoroquinolones/metabolism , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Hydrogels , Hydrogen-Ion Concentration , Kinetics , Models, Chemical , Moxifloxacin , Poloxamer/metabolism , Polysaccharides, Bacterial/chemistry , Sheep , SolubilityABSTRACT
Conventional eye drops shows relatively low bioavailability due to poor precorneal contact time. In situ hydrogels are of great importance in providing sustained ocular drug delivery due to their elastic properties hydrogels resist ocular drainage leading to longer contact times. In the present study an in situ gelling thermoreversible mucoadhesive gel was formulated of an antibacterial agent Moxifloxacin HCl using combination of poloxamer 407 and poloxamer 188 with different mucoadhesive polymers such as Xanthan gum and Sodium alginate with a view to increase in gel strength and bioadhesion force and thereby increase in precorneal contact time and there by increase in bioavailability of the drug. The formulations were evaluated for physical parameters like Clarity, pH, spreadability, drug content, gelation temperature, gel strength, bioadhesion force and in vitro drug release study. The formulated gels were transparent, uniform in consistency and had spreadability with a pH range of 6.8 to 7.4. A satisfactory bioadhesion (3298 to 4130 Dyne/cm(2)) on the sheep's corneal surface and good gel strength (95 to 128 sec) were also observed. As the concentration of mucoadhesive polymers in the gel formulation increases, the rate of drug release decreases. The order of drug release was Xanthan gum>Sodium alginate. It was concluded that a thermoreversible in situ gel formulation with Moxifloxacin HCl can be formulated by combining with mucoadhesive polymers and can effectively be used in safe and sustained ocular drug delivery with greater bioadhesion force and gel strength as compared to the thermoreversible polymers poloxamer 407 or 188 when used alone.
