A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.
The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.
Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.
Ergocalciferol is vitamin D2. Ergocalciferol is a fat-soluble vitamin that regulates calcium and phosphorus metabolism. Vitamin D is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. Ergocalciferol is 9. 10-secoergosta-5,7,10(19),22-tetraen-3- 01,(3b,5Z,7E,22E)-, (C28H44O) with a molecular weight of 39665. Ergocalciferol is a white, colorless crystal, insoluble in water, soluble in organic solvents, and slightly soluble in vegetable oils. It is affected by air and by light. Ergosterol or provitamin d2 is found in plants and yeast and has no antiarichitic activity. Vitamin D2 is derived from fungal and plant sources. Vitamin D2 is also known as ergocalciferol.