ABSTRACT
Objective:To achieve transbuccal release of carbamazepine by loading in unidirectional release mucoadhesive buccal patches. Methods:Buccal patches of carbamazepine with unidirectional drug release were prepared using hydroxypropyl methyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and ethyl cellulose by solvent casting method. Water impermeable backing layer (Pidilite? Biaxially-oriented polypropylene film) of patches provided unidirectional drug release. They were evaluated for thickness, mass uniformity, surface pH and folding endurance. Six formulations FA2, FA8, FA10, FB1, FB14 and FB16 (folding endurance above 250) were evaluated further for swelling studies, ex vivo mucoadhesive strength, ex vivo mucoadhesion time, in vitro drug release, ex vivo permeation, accelerated stability studies and FTIR and XRD spectral studies. Results: The ex vivo mucoadhesion time of patches ranged between 109 min (FA10) to 126 min (FB14). The ex vivo mucoadhesive force was in the range of 0.278 to 0.479 kg/m/s. The in vitro drug release studies revealed that formulation FA8 released 84%and FB16 released 99.01%of drug in 140 min. Conclusions: The prepared unidirectional buccal patches of carbamazepine provided a maximum drug release within specified mucoadhesion period and it indicates a potential alternative drug delivery system for systemic delivery of carbamazepine.
ABSTRACT
In this prospective study, 81 eyes of 70 patients diagnosed with various ocular surface disorders were enrolled to document the use of amniotic membrane transplantation in various ocular surface disorders. Detailed history and ocular examination was done. Ocular photographs and consent from all patients were taken. Fluorescein staining and impression cytology was done preoperatively and postoperatively in selected cases. Amniotic membrane was prepared from the placenta of a donor (consent taken and negative for infectious disorders), after separating amnion from chorion. It was washed with antibiotic solutions, transferred over nitrocellulose paper and stored in Dulbecco's modified Eagle's minimum essential medium at -80 degrees C. Recipient bed was prepared by removing the fibrovascular pannus and necrosed conjunctiva. Amniotic membrane was transplanted with the epithelial side up and sutured. Sixty-four eyes had good result by clinical evaluation or impression cytology findings, 5 eyes later required limbal stem cell culture and transplantation. All the 3 eyes had failure of the fornix reconstruction and 5 eyes had recurrence of the pterygium. Amniotic membrane provides lower recurrence rate in cases of recurrent pterygium. Alkali injuries are more dangerous but showed good response to amniotic membrane transplantation combined with limbal autografting or ex-vivo expansion and later transfer. Initial proper assessment of limbal involvement, conjunctival necrosis and corneal involvement is the key to the management of acute cases. Contracted sockets showed no improvement. Shield ulcers and persistent epithelial defect and ocular surface defects secondary to tumour excision showed excellent results.