Titanium Dioxide and Zinc Oxide :

Both are used in the Pharmaceutical Industry, but for Different Purposes :

Titanium Dioxide :

Used as a Pigment in Tablet Coatings, Gelatin Capsules, and Syrups.
It's also used in Sunscreens to Block UVB and UVA rays.
Titanium Dioxide can help Identify Oral Solid Dosage forms, which can help prevent Counterfeit Products.

Zinc Oxide :

Used as an Excipient to improve the Stability, Solubility, Bioavailability, or Shelf Life of Active Ingredients.
Zinc Oxide is also used in Sunscreens to Block UVA and UVB rays.

Both Titanium Dioxide and Zinc Oxide are FDA-Approved for use in Sunscreens.

They are used as Nanoparticles, which are Less Visible after Application and are more Cosmetically Acceptable

Zinc Oxide :

It is made using Zinc, a Critical Mineral Element used to keep Humans Healthy and found in many Multivitamins.
ZnO occurs Naturally in the Mineral Zincite, but most of the Commercial Products are made by the High-Temperature Oxidation of Zinc Ore.

Non-Irritating and easy on Sensitive Skin, Zinc Oxide has been used in Skincare for 1000s of years. A Skin Protectant widely used in Treating various forms of Skin Irritations, it’s used in Diaper Creams, Calamine Lotion, and Toothpastes. Zinc Oxide doesn’t Sting Eyes.

Titanium Dioxide or Zinc Oxide ?

The Best Sunscreen Active Ingredient, for Both Human and Marine Biosystems, is Non-Nano Zinc Oxide, and by a wide Margin.

Non-Nano Titanium Dioxide is a Distant Second-Best Choice, though it is Less Expensive than High-Grade Non-Nano Zinc Oxide, and it is Better than All Petrochemicals.

Titanium Dioxide & Calcium Carbonate ?

In the Pharmaceutical Industry, Both Titanium Dioxide and Calcium Carbonate are used for Different Purposes, but Calcium Carbonate is a Potential Alternative to Titanium Dioxide in some Applications.

Uses :

Titanium Dioxide is a Pigment used in Tablet Coatings, Gelatin Capsules, and Syrups. It's also used in Sunscreens to Block UVA and UVB rays. Calcium Carbonate is a Color Additive and can be used in Tablet Film Coatings.

Alternatives :

Calcium Carbonate is a Potential Alternative to Titanium Dioxide in Tablet Coating. It has a low effect on Viscosity Compared to basic Coating Solutions.

Regulatory Developments :

In the Pharmaceutical Industry, Titanium Dioxide and Calcium Carbonate are Both used in Different ways, but Calcium Carbonate is sometimes seen as a Potential Replacement for Titanium Dioxide.

Titanium Dioxide :

A Pigment used in Tablet Coatings, Gelatin Capsules, and Syrups. It's also used in Sunscreens to Block UVA and UVB rays.

Calcium Carbonate :

Used as a Color Additive and Common Additive in the Pharmaceutical Industry.

It's also used as a Calcium Supplement, Antacid, and Phosphate Binder to Treat Low Calcium Conditions, GERD and CKD.

Differences Between Titanium Dioxide and Calcium Carbonate :

Whitening Agent : Titanium Dioxide is more effective as a Whitening Agent than Calcium Carbonate.
Opacity Agent : Calcium Carbonate is an effective Opacity Agent in Sauces and Soups.
Film Coating : Calcium Carbonate can be used in Tablet Film Coatings.