Question
Posted on: March 6 2013Preparation of mouth rinse agent with tetracycline and hydrocortisone
F. Mouthwash < BR/> We have solubilized the Vit A oil with Tween 80 (8:1) and to improve the flavor we have replaced the mint with bitter orange peel tincture. Hydrocortisone is suspended but does tetracycline and lidocaine remain in solution? Otherwise, the tetracycline should not be precipitated because of better functioning at higher pH but what about the solubility of lidocaine? Is addition of xanthan gum useful for additional stabilization and viscosity? What about the shelf life because the effect of the parabens is not done by Tween and how to preserve it?
Answer
These are a whole row of questions. I would like to say beforehand that hydrocortisone is not a base!
Indeed tetracycline should be precipitate because of the rapid degradation of tetracycline in solution. A tetracycline suspension is described In the Galenic Formularium booklet. Subject to adaptation to the amount of tetracycline present in this Regulation, this formula may be used. The pH should be 5.5 to 6. I don't expect to have any major influence on the pH due to lidocaine. HCl, given the pH of an aqueous solution is between 4 and 5.5. A small control and adjustment of the pH may be appropriate anyway? A non-ideal pH may also express itself when the suspension is stored. To absorb the inclusion of the parabens by Tween, you can double the normal concentration of 0.1%. Of course, the tetracycline will also exert a conservative effect. The use of freshly cooked out water applies as usual also here.