FORMULATION, DEVELOPMENT AND OPTIMIZATION OF DAPSONE DEPOT INJECTION IN ACNE: IN-VITRO/IN-VIVO STUDY

The aim of this work is to design and develop a controlled release drug delivery system of the anti-acne agent (dapsone), also used as a leprostatic agent. Dapsone is a strong anti-inflammatory agent that makes it a more powerful treatment in dermatological disorders; its treatment in acne requires long term steady-state concentration in plasma. Poor patient compliance and long term treatment by an oral route leading to dapsone resistance, which stimulates the development of depot preparation. Depot injection consists of a PLGA polymer containing matrix, which gives control release up to 1 month. Microspheres were formed by solvent extraction/evaporation technique. Various parameters, like a selection of solvents, selection of drug: polymer ratio, glycolide: lactide ratio, and evaporation temperature, were important and optimized based on the results. The entrapment efficiency of microspheres was found between 40% to 70%. The initial burst of the drug was controlled and found to be 9.8% within 24 h of release. The inactive ingredients used for formulation development were found to be compatible based on FTIR comparison. The glass transition temperature of the microsphere was found to be 53.45 °C. The residual solvents like methanol and ethyl acetate were found within ICH limits in the finished product. The in-vitro release profile found between 80% to 95% after 30 days. The C_max of microsphere was found to be 2.04 mcg/mL which is lower as compared to immediate-release (4.82 mcg/mL). The controlled release of drugs from the microsphere provides constant plasma drug content for a long period of time and improves patient compliance by reducing dosage frequency.