Is it okay to take generic loratidine 2 times a day instead of once a day?

Yes and no: It comes in two formulations: 12 hour and 24 hour - clearly marked on the package. Take the 12 hour twice a day and the 24 hour once a day!

Loratadine? OK: The full adult dose of Loratadine in other parts of the world is 20 mg. That was the most effective dose. This amount caused a 12-14% drowsiness rate. This was not acceptable for marketing in the USA. The 10 mg dose was tested against Chlorpheniramine in order to find a non-drowsy dose and it worked. So for most 10 mg is fine. Worse allergy, 20mg would help and a few will develop drowsiness.