ABSTRACT
A filter paper disk method for the delivery of drugs to oral mucosal sites was evaluated. The water-soluble steroid prednisolone sodium phosphate was chosen as the tracer drug. The in vitro recovery of the steroid from the filter paper disks after placement onto glass was greater than 95% and within the pipetting error for the method. Filter paper disks containing 1.25 mg doses of prednisolone sodium phosphate were placed on three different intraoral sites for 5 minutes and the drug retention was calculated in six volunteers. The mean percentage retention at the three sites was 65.4% for the sublingual mucosa, 24.1% for the buccal mucosa, and 9.9% for the palatal mucosa. The differences between the sites were all significant. The method may be useful for studying the retention of other drugs at various oral mucosal sites and for determining the factors that affect such retention.
Subject(s)
Mouth Mucosa/metabolism , Prednisolone/analogs & derivatives , Absorption , Administration, Topical , Adult , Body Water/metabolism , Cheek/metabolism , Female , Humans , Male , Palate/metabolism , Prednisolone/administration & dosage , Prednisolone/metabolism , Tongue/metabolismABSTRACT
This study measured the absorption of isosorbide dinitrate (ISDN) into the systemic circulation after application of tablets to the buccal, palatal, or sublingual mucosa in six healthy subjects. After 1 minute serum levels were detectable by gas liquid chromatographic analysis from buccal and sublingual sites. Levels progressively increased, peaking at 5 minutes, and then progressively decreased during the 30-minute sampling period. At most of the time periods serum levels were greater from sublingual sites than from buccal sites. ISDN levels were not detected at any time in any subject after application to the palatal mucosa. As with the skin, the keratinized layer of the oral mucosa may be an important barrier to absorption. The findings appear relevant to the delivery of drugs via the oral mucosa for systemic effect.
