The present invention relates to slow release tablets for oral administration and, more particularly, to tablets which permit a prolonged period of contact between the medication and the buccal and gingival mucosa as well as the hard and soft tissues of the mouth.
Medications are generally administered with a pharmaceutical carrier with specific desired characteristics which can, for example, influence the rate of release of the medication from the carrier. The choice of carrier is thus determined by the desired medical outcome. For example, medications which have local effects in the mouth and throat are often administered in both solid and liquid form, depending upon the desired pharmaceutical effect.
Liquid and semi-liquid dosage forms, such as mouthwashes and toothpastes are frequently used for oral hygiene, but have the disadvantage of relatively short contact periods with the hard and soft tissues of the mouth and throat. Solid dosage forms, such as troches and lozenges, offer certain advantages for such local administration of oral medications. The terms lozenge and troche are used synonymously for any form of tablet designed to be held in the mouth for slow dissolution and release of medication such that prolonged contact of the medication with the mouth and throat is ensured. The medications administered with troches or lozenges are primarily local anesthetics, antiseptics, astringents or anti-tussives. Lozenges may be made by fusion, a candy molding process or by compression. Troches are usually manufactured by compression, as are most other tablets.
Although currently available troches and lozenges have the advantage of enabling medication to be in prolonged contact with the mouth and throat, such tablets still have a number of disadvantages. First, although troches and lozenges do not dissolve immediately, the rate of release of medication is still relatively rapid, on the order of about 15 minutes for total release. Second, these dosage forms have not been specifically tested with herbal medications, or medications derived from botanical materials. Thus, the efficacy of these dosage forms with herbal medications is unknown. Hereinafter, the term "herbal medication" refers to a medication derived from botanical materials or a biologically active extract of these materials.
There is thus a widely recognized need for, and it would be highly advantageous to have, a solid dosage form for oral administration of medication with local effects on the mouth and throat, which permits release of the medication over a prolonged period of time, which has been specifically tested for use with herbal medications and which permits prolonged contact between the active ingredient of the medication and the hard and soft tissues of the mouth and throat.