Formulation of Tinidazole Rectal Suppositories


Tinidazole was prepared as a suppository dosage form that couldbe used rectally in an attempt to render the drug available systemically bya route other than oral route, thus overcoming the side effects of the drugon the gastrointestinal tract. Also such dosage form could replace theintravenous administration whenever it is inconvenient.The influence of the type of suppository base and addedsurfactants on the physical properties and drug release was studied usinglipophilic bases (witepsole H-15, witepsole H-35) and water soluble bases[mixtures of polyethylene glycols PEG 6000:400:200 (30:35:35) andPEG 4000:1000 (30:70)].The results showed a good release of tinidazole from PEG basescompared to lipophilic bases because of the interaction between the drugand triglycerides of the lipophilic bases. Also the non ionic surfactantsincrease the release of tinidazole from witepsole H-15 base containingsuppository and the increase was greater for span 80 than tween 80.Also the influence of temperature and storage period on thephysical properties and release was investigated by storing the preparedsuppositories at 4˚C and 25˚C for 1, 15, 30 and 45 days. The resultsappeared that the temperature of storage affect the release of tinidazolefrom witepsole H-15, but had no effect on physical properties of thesuppositories. While the storage period at both temperatures had someeffects on the physical properties. On the other hand, temperature ofstorage affects the physical properties of polyethylene glycolsuppositories and release of the drug, in contrast to the period of storage,which had no effect.The expiration date of tinidazole in formula containingpolyethylene glycol 4000:1000 (30:70) was found to be about 3.3 years.