Description

While there isn’t a single universal “90 ml” serum with this exact name, several highly-rated products in India, such as those from Asaya, Fixderma, and Minimalist, are specifically formulated to address acne pigmentation and dark spots on dark skin or “skin of color”. 
Below is a general description of how these specialized serums work:

Product Overview
These serums are high-potency treatments designed to target stubborn hyperpigmentation, melasma, and post-acne marks. Because darker skin tones have more active melanin-producing cells, these formulas use ingredients that inhibit pigment production without causing the irritation that can lead to further marking. 
Key Benefits
Reduces Dark Spots & Scars: Actively breaks down excess melanin at the root to fade persistent spots and acne scars.
Prevents New Pigmentation: Blocks the enzymes (like tyrosinase) responsible for creating new dark patches.
Evens Skin Tone: Promotes cell turnover to replace pigmented cells with a clear, unified complexion.
Hydrates & Calms: Often includes soothing agents to reduce redness and keep the skin barrier healthy.
Typical Powerful Ingredients
Alpha Arbutin (2%): A safe, natural brightening agent that specifically targets melanin production to fade spots.
Niacinamide (5–10%): Refines pores, controls oil, and prevents pigment from reaching the skin’s surface.
Tranexamic Acid: Effective for stubborn melasma and post-inflammatory hyperpigmentation.
Vitamin C: A potent antioxidant that brightens dullness and repairs sun damage.
Hyaluronic Acid: Ensures deep hydration so the treatment doesn’t dry out the skin