RESUMEN
The development of a transdermal delivery system for isosorbide dinitrate (ISDN) using electron beam irradiation was studied. The solid state stability of the drug to irradiation was assessed. The drug was dissolved in 2-ethylhexylacrylate (EHA)-acrylic acid (AA) system and this solution was directly irradiated on a backing membrane (Scotchpak1006) at different doses to get transdermal patches. The developed systems were evaluated for residual monomer content, equilibrium weight swelling ratios (EWSR), differential scanning calorimetry (DSC), weight uniformity, thickness uniformity, drug content and content uniformity, peel strength, in vitro release, skin permeation kinetics and skin irritation potential. The developed system possessed excellent adhesive properties. Increase in the irradiation doses did not have a significant effect on the peel strength values. The systems exhibited promising skin permeation kinetics and no skin irritating potential, both of which are important properties for transdermal drug delivery. The ISDN-EHA-AA system developed at an irradiation dose of 50 kGy showed a higher skin permeation profile as compared to an internationally marketed transdermal matrix system of ISDN.
Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Dinitrato de Isosorbide/administración & dosificación , Dinitrato de Isosorbide/efectos de la radiación , Administración Cutánea , Animales , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Femenino , Técnicas In Vitro , Dinitrato de Isosorbide/farmacocinética , Permeabilidad , Conejos , Piel/metabolismo , Solubilidad , Temperatura , Factores de TiempoRESUMEN
PURPOSE: To compare manual phacofracture and phacoemulsification techniques. SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India. METHODS: This prospective, randomized study comprised 60 cases of age-related cataract randomly divided into 2 groups: 30 eyes had phacoemulsification and 30, manual phacofracture using a trisection technique. Postoperative evaluation was at 1 day, 1 and 6 weeks, and 3 months. The parameters evaluated were amounts of viscoelastic material and irrigating fluid used, the time required to manage the nucleus, postoperative best corrected visual acuity, endothelial cell loss, and complications. RESULTS: Mean viscoelastic material used intraoperatively (3.69 mL +/- 0.81 [SD] versus 1.76 +/- 0.54 mL) and the time required to manage the nucleus (7.78 +/- 2.07 minutes versus 2.53 +/- 1.18 minutes) were significantly greater in the phacofracture than in the phacoemulsification group, respectively. Best corrected visual acuity was significantly better in the phacoemulsification group on the first postoperative day; 64% had a visual acuity of 6/9 or better versus 37% in the phacofracture group. Endothelial cell loss at 3 months was 17.66 +/- 3.65% in the phacofracture group and 12.03 +/- 3.06% in the phacoemulsification group and central corneal edema persisting for more than 1 week, 7 and 0 cases, respectively. The differences between groups were statistically significant. CONCLUSION: More experience in and further modification of the manual phacofracture technique are required before it can be recommended as a safe alternative to phacoemulsification.