Multi-Target In Vitro Enzyme-Inhibitory Activity of Lipo Crystal, a Liposomal Vitamin C, Pineapple and White Tomato Nutraceutical Powder: Inhibition of Collagenase, Xanthine Oxidase, Tyrosinase and Hyaluronidase

Multi-ingredient nutraceutical powders are widely marketed for skin health, yet most are characterised against a single enzyme target, and few are evaluated as the finished, reconstituted article that a consumer actually ingests. We report an integrated in vitro characterisation of Lipo Crystal, a spray-dried sachet powder combining liposomal vitamin C with pineapple and white tomato extracts. The reconstituted matrix was assayed against four enzymes and two redox endpoints, and the finished powder was characterised for proximate composition, microbiological quality and toxic element content. Xanthine oxidase inhibition rose from 47.03 ± 1.40 % to 76.47 ± 0.50 % across 10–500 µg mL⁻¹, crossing the half-maximal threshold within the tested range at a reported half-maximal inhibitory concentration of 62.29 µg mL⁻¹. Collagenase inhibition rose from 56.12 ± 1.90 % to 70.45 ± 0.60 % over the same range, already exceeding half-maximal inhibition at the lowest concentration tested, which bounds its half-maximal concentration below 10 µg mL⁻¹. At 10 mg mL⁻¹ the matrix inhibited tyrosinase by 93.82 %, nitric oxide generation by 91.60 % and hyaluronidase by 89.95 %, and radical-scavenging capacity gave a half-maximal concentration of 46.52 µg mL⁻¹. The reconstituted matrix measured 392.7 ± 52.36 nm with a polydispersity index of 19.0 ± 6.3 % and a zeta potential of −1.4 ± 0.7 mV. The finished powder met microbiological limits, with an aerobic plate count of 220 cfu g⁻¹ and Escherichia coli, total coliforms, yeasts and moulds all below the limit of quantification, and arsenic, lead and mercury were each below quantification. The concurrence of xanthine oxidase inhibition with a conventional dermal-enzyme profile is the distinguishing feature of this matrix and suggests a combined dermal and purine-metabolic positioning rather than a single-target cosmeceutical one. Two methodological caveats are stated explicitly: the surface charge is not resolved from zero and therefore indicates an absence of electrostatic stabilisation, with stability attributable to steric rather than charge effects; and an intermittent micron-scale scattering population shows that the intensity-weighted diameter describes the whole reconstituted matrix rather than its vesicles. In the absence of reference inhibitors, these findings are hypothesis-generating and require controlled confirmation.