Ketotifen KT is one of antiallergic drugs, due to its first pass effect, the bioavailability of the drug is only 50%. The objective of this study was to formulate and evaluate suppositories containing KT and/or KT solid dispersion.
The in-vitro release of KT from suppositories was done using dialysis membrane method in phosphate buffer at pH 7.4. The release of KT from water soluble suppository bases was higher than that from fatty or emulsion suppositories bases. Among all PEGs bases (F4: PEG 6000: PG (20: 80)) showed a relatively higher release of KT. Formulations prepared with glycerin bases gave more or less identical release pattern; relatively formula (F17: Gelatin: Glycerin: Propylene glycol: Water) gave the highest release pattern. Formula (F20: Suppocire AM) exhibited the highest release rate among fatty bases. Within all emulsion bases (F23: W15: W75: Tween 20: Span 60: PEG 1500: Propylene glycol) showed highest release rate. KT solid dispersion led to a higher release rate of the drug from selected bases.
A histological comparison between control group of rabbits (didn`t take suppository), another group took plain suppositories and group that received suppositories containing solid dispersion of KT was carried out. The tested plain and medicated bases didn't injure the rectal mucosa of rabbits. In conclusion the incorporation of solid dispersion in formula (F4) complied with the pharmacobeial limits for hardness, dissolution time, content uniformity and weight variation. Also it showed a relatively higher in-vitro release of KT and considered as safe and useful formulation for clinical use.