Hi Jay, Amphotericin B is indeed badly soluble. Alas I have no solubility profile but can only offers some tips. One may use DMSO which shows relatively high solubility: a few mg/ml. Amp B has two chargeable groups (pKa 5 and 10 if I am not mistaken) which means that at high pH, let's say 12, it should dissolve better in water.

You may want to look up:

Mazerski, J., J. Grzybowska, and E. Borowski. "Influence of net charge on the aggregation and solubility behaviour of amphotericin B and its derivatives in aqueous media." European Biophysics Journal 18.3 (1990): 159-164.

Your best shot at making it better soluble is to make a conjugate with another substance, like arabinogalactan via Schiff's base.

Falk, Rama, Abraham J. Domb, and Itzhack Polacheck. "A novel injectable water-soluble amphotericin B-arabinogalactan conjugate." Antimicrobial agents and chemotherapy 43.8 (1999): 1975-1981.

To encapsulate it, perhaps first dissolve in DMSO, next add this to your encapsulant and next use a rotavapor at low vacuum to distil of the DMSO.

I hope this helps, kind regards, Leo

try to use a blend of surfactants and/or cosolvents. 

Thanks @Leo for your response. I have checked its solubility in DMSO, but i was trying to get its solubility in some fixed oils or surfactants or even co-surfactants. Infact I have tried several combination but not able to achieve desired solubility? can you suggest further!

Thanks @Ahmed, but can you just add to your answer which surfactants and/or cosolvents you are speaking about. I have tried many such combination but practically not able to achieve adequate solubility. Can you be specific to ant of them if you have expirienced any? Thaning you!

Thanx @Yuvraj. I have noted all your suggestion.