Masao Ueno

Rapidly Absorbed Solid Oral Formulations of Ibuprofen Using Water-soluble Gelatin

Abstract— Rapidly absorbed oral dosage forms of ibuprofen using water‐soluble gelatin (hydrolysate of common gelatin: mean mol. wt: 6000) have been studied and compared with tablets prepared with common gelatin (mean mol. wt: 100 000) and commercial tablets. Spray‐dried and speed‐kneaded powders, two types of granules and tablets were prepared with water‐soluble gelatin. The in‐vitro dissolution rates of water‐soluble gelatin preparations were significantly faster than those of commercial tablets, whereas the tablets prepared using common gelatin had slower dissolution rates than commercial tablets. Water‐soluble gelatin enhanced the dissolution rate of ibuprofen by improving the wettability of the drug particle surface by water, without any interaction in solution and the solid state. The absorption behaviour of various preparations was evaluated in four beagle dogs. The peak concentration time (tmax) of the water‐soluble gelatin preparations was significantly shorter than that of tablets prepared with common gelatin and commercial tablets. The maximum concentration (cmax) and the area under the serum concentration‐time curve (AUC0–10 h) were similar in all cases. The serum concentration profiles of water‐soluble gelatin solid preparations were almost the same as those of the solutions. On the other hand, the profiles of the common gelatin tablets were similar to those of the commercial tablets. The mean absorption time (MAT) from water‐soluble gelatin preparations was about 0.7 h, while the MAT from commercial tablets and common gelatin tablets was about 1.2 h. The differences in the MAT of water‐soluble gelatin preparations and commercial tablets or common gelatin tablets were the same as the differences in mean dissolution time (MDT) in gastrointestinal fluid. The MDTs of the water‐soluble gelatin preparations were from 1 to 5 min, so both disintegration and dissolution steps were rapid. The water‐soluble gelatin preparations were stable at 40°C and 70% RH for at least 30 days. The results suggest that the water‐soluble gelatin is a useful additive to solid ibuprofen formulations as it may initiate a more rapid and uniform dissolution and absorption of the drug.