Sunscreen creams containing naringenin nanoparticles: Formulation development and in vitro and in vivo evaluations

Background: The aim of this study was to develop sunscreen creams containing polymeric nanoparticles (NPs) of naringenin for photoprotective and antioxidant effects. Methods: Polymeric NPs of naringenin were prepared and optimized. The NPs were incorporated into sunscreen creams and evaluated for in vitro and in vivo skin retention. Results: The optimized naringenin NPs showed a size of 131.2 nm, zeta potential −25.4 mV, and entrapment efficiency 32.45%. The absence of drug-excipient interaction was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. X-Ray diffraction analysis demonstrated the amorphization of naringenin in nanoparticles. Transmission electron microscopy showed the sphericity of the NPs with the size of <200 nm. Cytotoxicity assessment in HaCaT cells indicated non-toxic nature of naringenin NPs. In vitro skin permeation studies demonstrated that higher amount of naringenin permeated at the end of 12 hours (Q_12 hours = 184.03 ± 3.37 μg/cm²) and deposited in the skin (10.38 ± 0.48 μg/cm²) from NPs as compared to plain naringenin. Sunscreen creams (SC1-SC5) containing plain naringenin or NPs with/without nano-zinc oxide and nano-titanium dioxide were prepared and evaluated. Optimized cream (SC5) containing naringenin NPs showed highest SPF value and enhanced skin retention of naringenin in comparison with NPs in suspension form and other cream formulations. Conclusion: Optimized nanoparticulate sunscreen cream exhibited highest skin retention and negligible skin permeation of naringenin besides showing excellent SPF value.