US EPA

8327073 

Journal Article 

Benzoyl peroxide microcapsules. I. Preparation of core material 

Tatapudy, H; Madan, PL 

1995 

Indian Drug Manufacturers' Association 

32 

6 

239-248 

English 

The non-aqueous-separation coacervation process for a defined solvent/non-solvent system to prepare benzoyl peroxide in situ and suitable for microencapsulation was studied. Among the various solvents and nonsolvents investigated, methylene chloride (solvent) and n-hexane (non-solvent) were found to be most suitable. The volume of n-hexane added, mixing time, and the rate of addition of n-hexane affected the amount, but not the particle size of benzoyl peroxide precipitated. The maximum yield of benzoyl peroxide was obtained when 80 mL of n-hexane was added at a rate of 3.15 mL/min into a methylene chloride solution containing 200 mg/mL of benzoyl peroxide, and the mixture was stirred for 30 minutes at 517 rpm. The mean particle size of benzoyl peroxide obtained under optimum processing conditions was 81 μm with 90% of the particles being less than 135 μm. Preliminary microencapsulation studies with the precipitated benzoyl peroxide have shown promising results.