USE OF A HARD GELATIN CAPSULE AS A RECTAL DOSAGE FORM

The aim of the present study tvas to determine, using ibuprofen as a m odel drug, whether hard gelatin capsules were of value as rectal dosag e forms in man. The effects of training in administration of the capsu les and use of liquid paraffin as a glidant were also studied. The inf luences of different diluents in the capsule, i.e., lactose, dicalcium phosphate and hydroaxypropyl methylcellulose, on the bioavailability of ibuprofen were determined The results showed that ibuprofen is adeq uately absorbed after rectal administration via hard gelatin capsules. Training in administration and use of a glidant to facilitate rectal administration nonetheless played an important role. The type of dilue nt used markedly affected bioavailability. Capsules containing lactose behaved like immediate release formulations. Those containing hydroxy propyl methylcellulose behaved like prolonged release products.