Hi Dianna, and welcome to the FDMB!! The best place you could be to help learn all their is to know about diabetic kitties!
I answered on the Facebook page, but just in case you missed it, yes, Lantus is the same whether in a vial or pen. The only difference is that the vial has 10ml (1000 units) and although if it's kept refrigerated, can last for 6 months, usually you're not going to be able to use it down to the last drop.
The Solostar pens come in boxes of 5, with each "pen" being 3ml (300 units) so a box of 5 would be 1500 units of Lantus. If you call around, you may be able to find a pharmacy willing to split open a box and sell you just 1 pen. Target and hospital pharmacies are two that I've heard others have had luck with. There's also a
Lantus Savings Card that you can try to use. It will bring the price down to $25 for the first 6. You need to either say you're over 18 or the caretaker of a child. If you go with the pens, you can use every last drop.
Now lately, there has been some problems using the card. Not all pharmacies are taking it because of a new regulation that requires a special number that vets can't get, but I just recently saw someone who was able to use it, so I guess at this point it's just a matter of luck.
The one thing you need to know about the pens is that you can NOT use the needles that come with it or the "dial a dose". That's meant for humans that are on much bigger doses than our kitties are. Here we use .25 unit dose adjustments and that's just not possible with the Pen's "dial", so you' will need to buy syringes. You just take the "cap" off the pen, and there's a rubber stopper just like the ones on the vials. You''ll need u100 syringes with 1/2 unit markings.
Good luck to you and if you have any questions, please feel free to ask.