By having the file, it would be possible to try to brute force the password, so you would need to choose a really strong password to protect it and make brute forcing infeasible. Eg I can find on google tools that claim to brute force PKCS#12 at 500k passwords per second. If you choose 8 random printable characters it would take more than 400years. That on a comercial tool with GPU acceleration. Looks safe enough for your scenario.
However, sharing the key with other developers should be avoided anyway. Since you will need to share securelly the password anyway by another channel, and you should chose a password that is really strong, maybe you can use the same channel to securelly share the PKCS#12, and, if not, sending both using two separate distinct and private channels still is a better option.