WO-A-95/24893 discloses a delivery system for a hydrophobic drug. Bioavailability of the hydrophobic drug is improved in vivo by the use of a drug carrier system comprising a digestible oil and a relatively high level of a pharmaceutically acceptable surfactant component including a hydrophilic surfactant component which inhibits in vivo lipolysis of the oil and a lipophilic surfactant component capable of substantially reducing the inhibitory effect of the hydrophilic surfactant component. The digestible oils disclosed are not those which have an odor which is generally regarded as being offensive. EP-A-0127297 discloses encapsulated vitamin or mineral compositions in which the bioavailability of, inter alia, oil-soluble vitamins is improved by including 30 to 80% (preferably 35 to 75%) by weight of a polyoxyethylene sorbitan ester such as Polysorbate 80 in the composition, with the objective of forming a microemulsion of the oil-soluble vitamins in the gastrointestinal tract. The composition may further include a diluent in the form of an alcohol, a vegetable oil or a derivative thereof. Thus, EP-A-0127927 is not concerned with mitigating the problems of eructation following ingestion of an odoriferous oil such as fish oil.
WO 98/42319 discloses essentially non-aqueous compositions for oral administration which contain a biologically active oil or oil-soluble ingredient, such as oil-soluble vitamins, maintained as a dispersion in a carrier oil by means of an emulsifier system having an HLB (hydrophobic/lipophilic balance) value of 10 to 18. The objective of this is similar to that of EP-A-0127297, namely to improve bioavailability of the active ingredient by causing it to become finely dispersed in the gastric juices upon administration. The use of fish oils amongst a large number of possible biologically active oil or oil-soluble ingredient is disclosed, but there is no mention of the eructation problems associated with the use of such oils. The avoidance of undesirable taste is mentioned as an advantage of using a capsule dosage form as compared with a liquid dosage form.
U.S. Pat. No. 6,056,971 discloses a method of enhancing the dissolution properties in the gastrointestinal tract of relatively water-insoluble dietary supplements, particularly coenzyme Q-10 (ubiquinone). The method involves mixing a non-ionic surfactant with a polyhydric alcohol to form a uniform mixture and then mixing in the dietary supplement to form a non-aqueous solution which contains about 20 to 90% by weight of the surfactant and about 2 to 50% by weight of the polyhydric alcohol. The solution can then be encapsulated in a soft gel capsule. There is no mention of the eructation problems associated with the ingestion of odoriferous oils such as fish oil.
U.S. Pat. No. 5,900,251 discloses an essentially herbal or herbal extract composition for the treatment and control of breath odors and for aiding digestion, which contains ginger, licorice, chamomile, parsley seed oil and sunflower seed oil in an ingestible delivery system such as a capsule. The ginger, the licorice and the chamomile are present as preferred herbal or herbal extract digestive aids and none of those has an odor which is generally regarded as being offensive. The parsley seed oil is present as a preferred breath cleansing ingredient for cleansing the breath of odors, such as that of chime, generated in the stomach and/or other portions of the intestinal tract. The sunflower seed oil is present as a preferred ingestible oil carrier. The composition further includes an emulsifier and a suspending agent. The suspending agent is provided to suspend the active ingredients in the oil carrier. The emulsifier is typically selected from natural emulsifiers, synthetic surface active agents and solid particle emulsifiers. The purpose of including the emulsifier is not specifically disclosed, although it may be deduced from column 2, lines 54 to 58, that it is present to provide, together with the oil carrier and the suspending agent, a suitable delivery vehicle so that the active ingredients can be delivered to the stomach or lower in the digestible tract without significant release in the oral cavity, throat or esophagus.
GB 2324457 discloses a dietary supplement comprising a nutritional oil emulsified into water with an emulsifying agent to form a micellised droplet. This droplet is encapsulated with a modified starch such as a vegetable oligosaccharide. The modified starch coating serves to protect the oil from degradation by exposure to oxygen and UV light. The starch coating also masks the flavor, odor and texture of the oil.
WO 89/02223 is concerned with preventing flavor degradation of non-hydrogenated fish oils in stable emulsions such as salad dressings. The improvement is obtained by the incorporation into the food product of small amounts of fructose. An oil soluble flavor masking agent such as lemon oil may also be included in the product. Similarly, U.S. Pat. No. 4,961,939 is concerned with the prevention of formation of malodorous alcohols and aldehydes from water-in-oil or oil-in-water emulsions containing fish oil, whereby to eliminate undesired odor and off-taste.
GB 2349817 discloses a soft gelatin capsule having a masking agent added to the capsule contents and a masking agent incorporated into the capsule shell itself. Orange oil is given as an example of the masking agent. The product is said to have improved taste during swallowing, reduced rebound aftertaste and reduced odor.
CA 2293088 is concerned with masking the odor and taste of fish oil in, for example, dietary supplements, without introducing a stronger taste or scent. This is achieved by mixing the fish oil to be masked with thyme essence. It is a particular problem with ingestible compositions containing such odoriferous oils as fish oils that eructation (or reflux) tends to occur soon after ingestion, resulting in an unpleasant taste in the mouth and a very unpleasant odor on the breath of the person ingesting such a composition, even when the composition has been swallowed whole without chewing.