Note: The restrictions I speak of were instituted by the Philippine Government to protect mostly women who were being lured into jobs in the middle east and were kept there as virtual slaves and their passports taken from them. But theses 'protections' have been applied broadly in some cases
The Philippine Governent has restrictions on citizens flying out of the country - especially alone. And may demand proof of financial ability to afford a ticket back home. I know of instances where Philippine citizens were denied visas to go to Thailand by the Philippine government. I suggest you to check this out before buying airline tickets