RESUMEN
The different barriers that slow the penetration of active ingredients administered by the ocular route are described, and some novel dosage forms designed for this route are discussed. Both precorneal and corneal factors considerably restrict ocular penetration. The low bioavailability of classical ophthalmic dosage forms can be improved by several approaches, particularly by increasing the time the active ingredients remain in contact with the eye tissues. The new dosage forms are reviewed according to their type and their drug release mechanisms. The characteristics, advantages, and limitations of each are outlined. The potential of these dosage forms can be expected to enhance development. They offer prolonged effectiveness, reproducibility, fewer unwanted side effects, and improved tolerance.
Asunto(s)
Vías de Administración de Medicamentos , Sistemas de Liberación de Medicamentos , Soluciones Oftálmicas/farmacologíaRESUMEN
A good immediate ocular tolerance of eye-drops is paramount for the patient's compliance, and therefore for the therapeutic success. The tolerance of a new formula of NAAXIA, an anti-allergic eye-drop, whose sole modification was the replacement of the Mg++ ion by the Na+ ion, was compared with the previous formula. One drop of each preparation was instilled in one eye so as to make an intraindividual comparison. Just after instillation, each subject was asked to express what he felt, and which eye-drop he preferred. The answers, reported on a sequential analysis graph, clearly show that in all three groups (healthy adults, red-eyed adults, red-eyed children) the slight alteration of the formula led to a marked improvement in immediate tolerance.
Asunto(s)
Dipéptidos/efectos adversos , Antagonistas de los Receptores Histamínicos H1/efectos adversos , Adulto , Cationes , Niño , Enfermedades de la Conjuntiva/tratamiento farmacológico , Método Doble Ciego , Evaluación de Medicamentos , Humanos , Magnesio , Soluciones Oftálmicas , SodioAsunto(s)
Lentes Intraoculares , Comercio , Humanos , Lentes Intraoculares/normas , Óptica y Fotónica , EsterilizaciónAsunto(s)
Afaquia/terapia , Lentes de Contacto , Estudios de Evaluación como Asunto , Gases , Humanos , PermeabilidadRESUMEN
Fifty patients with allergic conjunctivitis were included in a double-blind randomized clinical trial designed to compare the efficiency and tolerance of two antiallergic eye-drops: one containing NAAGA (22 patients), the other one containing disodium Cromoglycate (28 patients). Both treatments were used at a dosage of 1 drop 4 times per day. Ocular symptoms, conjunctivo-corneal signs and the subjective ocular condition assessed by the patients themselves with visual analogue scales, were all significantly improved by both eye-drops during the first month of treatment. Statistical analysis showed that patient ocular condition improved more rapidly with NAAGA eye-drops. In 25 patients (12 in the NAAGA group and 13 in the Cromoglycate group), the study was continued for an additional month according to a cross-over protocol. During the 2nd month of treatment, additional improvement of ocular symptoms and signs were observed with both eye-drops but more markedly in those patients who received NAAGA after Cromoglycate. Ocular tolerance was good for both eye-drops.