I wanted to know anything about a suitable commercially available cell lines which could be utilized for testing the efficacy of drugs against Alzheimer's disease.
What is the intended target for the drugs you are screening?
The commercially available cell lines aren't models of the disease. All you can show is a proof-of-principle, that the drug affects specifically the intended target(s).
Hippocampal neuronal cultures which you would have to harvest yourself from 18- to 19-day-old rat embryos is still the gold standard for these types of studies.
But you could look into using SH-SY5Y neuroblastoma cells.
In my old lab, we used the organotypic hippocampal slice culture model. We took PND12 SD rat hippocampi and grew them for in vitro Alzheimer's drug studies. Our method was very similar to this protocol on JoVe: