Characterisation of a novel gelatin-based system for oral delivery of pharmaceuticals and nutraceuticals
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Abstract Oral delivery is one of the most utilized routes for pharmaceutical delivery, due to its simplicity, convenience and thoroughly evaluated safety-profile. Significant drawbacks are however associated with conventional (tablets) oral drug delivery, including poor bioavailability and various challenges related to patient compliance. Water-in-oil-in-water (W/O/W) emulsion based delivery units, has been proposed as a potential mean to overcome the above-mentioned hurdles. Nutraceutical agents are also usually delivered through the oral route. If a nutraceutical supplement is to obtain sufficient consumer compliance, it needs to possess a balance between reasonable sensory attractiveness/acceptance and nutritional relevance. The attainment of this balance is especially challenging for multivitamin/mineral supplements. ConCordix is a system, currently being exploited for delivery of nutraceuticals. In a ConCordix based delivery unit the active agent is contained within a soft and chewable gel matrix. It has been suggested that the ConCordix provide enhanced compliance properties by granting taste-masking opportunities and by circumventing the problem of dysphagia. The objective of the current study was to contribute in the further investigation and development of the CCx technology as a platform for delivery of pharmaceutical and nutraceutical agents. Three separate studies were conducted to achieve this; each addressing a different challenge related to CCx based delivery systems. The first study was executed to investigate the stability of W/O/W emulsions. Dextromethorphan (Dextro) was used as a model compound, which was encapsulated within the internal water phase, alone or in inclusion complexes with various cyclodextrins. The external water phases were altered by addition of sodium chloride or gelatin. The stability of the different systems during storage was assessed by performing droplet size measurements, and by performing liquid-chromatography mass-spectrometry analysis to assess the encapsulation efficiency. By presenting dextro as an inclusion complex using HP-β-cyclodextrin, a fourfold increase in the aqueous solubility was achieved. An increased encapsulation of dextro was also observed by presenting it as an inclusion complex with either HP-β-cyclodextrin or γ-cyclodextrin The second and third studies were conducted to assess issues related to CCx as delivery system for two specific nutraceutical ingredients, ascorbic acid and calcium. Ascorbic acid is known to be unstable and prone to decomposition under conditions that typically will exist in a CCx based delivery unit, a set of experiment was therefore performed to assess how different parameters affect the stability of ascorbic acid. Knowledge of this is relevant as it may provide guidance toward stability-enhancing actions. Different samples containing ascorbic acid was prepared, and the effect of different parameters on colour-formation (related to decomposition of ascorbic acid) was assessed. The obtained results suggested that temperature, the presence of protein (cold water fish gelatin), water activity, pH and the presence of oxygen were important parametersThe presence of particles is known to affect the rheological properties of gels, and the presence of calcium in a chewable nutraceutical supplement could have great impact on the texture of the delivery unit, which further could influence the perception and mouth-feel of the supplement. Filled gels were prepared using type A or type B gelatin with different amounts of tri calcium phosphate (0-15 wt.%) as filler phase, and a rheometer was used to investigate how the presence of the particles affected the rheological properties of the gels. Obtained results suggested that calcium particles provide structural reinforcement to the filled gels prepared with both type A and type B gelatin, and thus behave as active fillers in both systems. For the samples prepared with type A gelatin, enhanced solid-like behaviour was observed with increasing fractions of calcium at elevated temperatures (>40 C). The choice of a suitable polymer component might therefore be critical to achieve desired rheological properties for a CCx based calcium supplement.