Preparation method for adapalene gel

The invention discloses a preparation method for adapalene gel. The preparation method comprises the steps that carbomer 934 is soaked in purified water for 24h and screened to obtain a carbomer solution; adapalene, propanediol and sodium hydroxide are taken, dissolved in purified water and added into a stainless steel barrel for a water bath to obtain a main drug solution; methylparaben, poloxamer188 and propanediol are taken, poured into a beaker, stirred and dissolved in a water bath to be clarified; purified water and edetate disodium are taken and placed in a main pot to be stirred at a low speed for dissolution, the solution in the beaker is poured into the main pot, sodium hydroxide is added, and the mixture is stirred to be dissolved; the carbomer solution is poured into the main pot and stirred slowly into uniform gel; the main drug solution is poured into the gel, the stainless steel barrel is rinsed with propanediol before the gel is poured into the main pot, and the mixture is stirred on a vacuum condition to obtain a material; the pH of the material is regulated to 4.75-5.25, quick stirring is started, and vacuum degassing, slow stirring and discharge are performed in sequence. The granularity of the adapalene gel prepared through the method reaches 50 micrometers, meeting the standard requirement for preparations.