RESUMO
In the present investigation, the effect of timolol maleate loaded ocuserts was studied as an alternative for conventional anti-glaucoma formulation. Ocuserts were prepared using natural polymer sodium alginate and ethyl cellulose. Physico-chemical properties along with drug entrapment efficiency (94-98%), content uniformity (93.1%⯱â¯0.264-98.00%⯱â¯0.321), in vitro drug release (83.42%⯱â¯0.35 at end of 12â¯h), ex vivo permeation all showed satisfactory results, which was found to follow zero order kinetics. Ex vivo permeation studies showed better results, revealed that the permeability coefficient was dependent on polymer type. The sterility test accelerated stability studies and in vivo studies such as eye irritancy test, in vivo drug release of the optimized ocusert was determined. The anti-glaucoma activity was measured using Schiotz tonometer at different time interval. Significant reduction in Intra ocular pressure (IOP) within 3â¯days was observed in case of rabbits treated with ocusert in comparison to the rabbit treated with marketed eye drop formulation. Hence timolol maleate loaded ocuserts proved to be a promising and viable alternative over conventional eye formulation for the sustained and controlled ophthalmic drug delivery, targeting the drug within the ocular globe thus improving patient compliance for the treatment of glaucoma.
Assuntos
Glaucoma , Pressão Intraocular/efeitos dos fármacos , Pilocarpina , Timolol , Animais , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Glaucoma/tratamento farmacológico , Glaucoma/metabolismo , Glaucoma/patologia , Cabras , Pilocarpina/química , Pilocarpina/farmacocinética , Pilocarpina/farmacologia , Coelhos , Timolol/química , Timolol/farmacocinética , Timolol/farmacologiaRESUMO
Smart polymers have enormous potential in various applications. In particular, smart polymeric drug delivery systems have been explored as "intelligent" delivery systems able to release, at the appropriate time and site of action, entrapped drugs in response to specific physiological triggers. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. The responses vary widely from swelling/contraction to disintegration. Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications. The most fascinating features of the smart polymers arise from their versatility and tunable sensitivity. The most significant weakness of all these external stimuli-sensitive polymers is slow response time. The versatility of polymer sources and their combinatorial synthesis make it possible to tune polymer sensitivity to a given stimulus within a narrow range. Development of smart polymer systems may lead to more accurate and programmable drug delivery. In this review, we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules, and we highlight various applications in the field of advanced drug delivery.