The delivery of biologically active components that are susceptible to moisture or are otherwise compromised by environmental factors has been a continuous problem for those presented with the challenge of formulating such components in a stable product. Indeed, a variety of mechanisms have been proposed, for example, encapsulation of hygroscopic materials or inclusion of agents such as dessicants. However, these mechanisms on their own may not always be suitable or effective for use.
Even further, many components are desirable for delivery to specific locations in the mammalian system, for example, the jejunem, ileum, or other locations in the intestinal tract. Such components are often enterically coated for targeted intestinal delivery and prevention of degradation in acidic environments such as the stomach. However, such enteric coatings may not be effective in preventing moisture from affecting, or coming in contact with, the susceptible component.
For example, it has recently been reported that certain probiotic components that are isolated from healthy gastrointestinal tracts are useful for treating inflammatory conditions such as inflammatory bowel disease or irritable bowel syndrome. Indeed, successful delivery of such components to the inflamed portions of the gastrointestinal tract, for example the intestines, is likely to be an important advance in treating these conditions. However, oral administration of such components has proven challenging, as such probiotic components necessarily pass through non-native locations of the gastrointestinal tract, for example the acidic environment of the stomach, where the probiotic components can be quickly degraded. Moreover, the shelf stability of such components, perhaps primarily due to susceptibility to moisture, may not be suitable or practical for product manufacturers.
As a result, there is a continuing need for compositions that are useful for maintaining the integrity of susceptible probiotics and other components such as vitamins and certain other sensitive biologically active agents. Surprisingly, the present inventors have discovered compositions which are suitable for effective delivery of one or more of such susceptible components. The inventors have discovered that compositions comprising at least two layers surrounding the core which contains the component, wherein the layers are an enteric layer and a hydrophobic layer, respectively, provide surprisingly optimized stability. Such compositions are suitable for use with susceptible components such as probiotics, even wherein an extended shelf life is necessary for commercial delivery. These and other benefits of the present invention are described herein below.