Search

A Novel approach was developed for the preparation of controlled release proniosome-derived niosomes, using sucrose stearates as non-ionic biocompatible surfactants for the nebulisable delivery of cromolyn sodium. Conventional niosomes were prepared by a reverse phase evaporation method followed by the preparation of proniosomes by spraying the optimized surfactant-lipid mixture of sucrose stearate, cholesterol and stearylamine in 7:3:0.3 molar ratio onto the surface of spray dried lactose powder. Proniosome-derived niosomes were obtained by hydrating proniosomes with 0.9% saline at 50 degrees C and mixing for approximately 2 min. All vesicles were evaluated for their particle size, morphological characteristics, entrapment efficiency, in vitro drug release, nebulisation efficiency and physical stability at 2-8 degrees C. In addition, coating carrier surface with the surfactant-lipid mixture, during preparation of proniosomes, resulted in smaller, free flowing, homogenous and smooth vesicles with high drug entrapment efficiency. Compared to a standard drug solution, a successful retardation of the drug release rate was achieved with the proniosome-derived niosomes, where the t50% value of the release profile was 18.1h compared to 1.8h. Moreover, high nebulisation efficiency percentage and good physical stability were also achieved. The results are very encouraging and offer an alternative approach to minimize the problems associated with conventional niosomes like degradation, sedimentation, aggregation and fusion.

Glucose monohydrate and sorbitol were evaluated as alternative carriers to á-lactose monohydrate in dry powder inhalations. Cromolyn sodium (CS) - carrier binary formulae were prepared and tested in vitro by aerosolization via a twin stage impinger using three types of inhaler devices; Spinhaler, Aerolizer and Handihaler. Glucose monohydrate and sorbitol-containing formulae that were inhaled via a Handihaler showed significantly higher drug fine particle fractions (P<0.001) than that of the same formulae aerosolized via other devices. Upon storage of the prepared formulae under uncontrolled humidity, that may be encountered during storage and use, marked reductions in these fractions were observed. Incorporation of an optimum Aerosil 200 concentration, as a ternary component, minimized this effect. A urinary excretion pharmacokinetic method was used to evaluate the bioavailability of the selected ternary formulae, inhaled via a Handihaler, relative to the marketed Intal Spincaps, inhaled via a Spinhaler. It was found that the relative bioavailability percentages of the developed formulae were more than twice that of the marketed one suggesting possible future utilization of these more effective ternrry formulae using the more efficient Handihaler inhaler device.