Development and evaluation of phosphatidylcholine complexes of some phytopharmaceuticals as skin whitening agents

Abstract

Arbutin and curcumin are widely used for the treatment of hyperpigmentation. A very hydrophilic drug (arbutin) is unable to penetrate the skin, while a very lipophilic drug (curcumin) has the propensity to remain in the layers of the stratum corneum; so, there is a need for enhancement of penetration for both drugs. Gel containing phosphatidyl complexes of drugs have emerged as one of the most interesting topical delivery systems as it has dual control release systems i.e., gel and complexes. One side the topical applications of the drugs offers the potential advantages of delivering the drug directly to the site of action and secondly delivering the drug for an extended period of time at the affected site. The major objective behind this formulation was enhancing the topical delivery of both drugs by formulating gel containing phosphatidylcholine complexes. Complexes of both drugs were prepared using thin-film hydration technique using rotary flask evaporator and the percentage entrapment efficiency in complexes was optimized to 68.73 ± 3.29 and 87.23 ±1.61 for arbutin and curcumin, respectively. Optimization of complexes was performed by Box- Behnken reduced surface response design, evaluation of optimized batch by percentage entrapment efficiency, particle size, zeta potential, and in - vitro drug release study by Franz diffusion cell. Optimized formulation of complexes of both drugs incorporated into gel base and evaluated for visual examination, spreadability, pH, and viscosity. The prepared gel was light yellowish in color and showed good homogeneity with the absence of lumps and syneresis. Spreadability, pH, and viscosity of prepared gel were found 5.86 ± 0.057 cm, 5.53 ± 0.115, and 17535.66 ± 5.859 cp, respectively. The in-vitro drug release was found 81.05 ± 2.62 and 77.67 ± 3.60 after 300 minutes for arbutin and curcumin, respectively from the prepared gel. Simultaneous estimation of arbutin and curcumin was performed by RP-HPLC. Recovery of arbutin and curcumin from the prepared gels was 99.66 ± 0.16 %