In Pathfinder, potions are considered magic items like scrolls or wands and are made in much a similar way. Potions and oils can be made from any spell (or, if you're an Alchemist, formula) up to 3rd level with a casting time of less than one minute that affect one or more creatures.
When you make a potion, you spend material components to do so, which are represented as the gold you pay. You don't just turn the gold into a potion, you use it to purchase ingredients, containers, tools, etc. that you end up consuming when brewing a potion or oil. The value for a potion is equal to the Spell Level x Caster Level x 50 gp. When you brew a potion yourself, you divide the value in half to determine the cost of materials. For example, a Potion of Cure Moderate Wounds would cost 150 gp to make (Level 2 Spell x Minimum Caster Level 3 x 50 / 2). The ingredients themselves may vary between spells, the gold is just used as an abstraction of purchasing ingredients or the effort in finding them yourself.
You must also dedicate time to making a magic item such as a potion. In Pathfinder, potions and scrolls that cost less than 250 gp to make take 2 hours. All other magic items (including potions worth more than 250 gp) take 8 hours for every 1,000 gp of their base price (before you divide it in half for materials) with a minimum of 8 hours. The Potion of Cure Moderate Wounds mentioned earlier would therefore take 8 hours to brew (because its base price is 300 gp, which is more than 250 gp).
To brew the potion, you must work in a place without distractions for up to 8 hours/day. You can work while adventuring for 4 hours/day, but it only counts as 2 hours of work. Otherwise you work in 4 hour blocks that cannot be interrupted in a quiet place with the tools necessary to make the item. You make a skill check (Spellcraft or Craft (alchemy) for potions) versus a DC of 5 + Caster Level of the item. Failing means the materials are wasted and the process must start again. Failing by 5 or more creates a cursed item. You can only work on one magic item at a time.
You must prepare or have the ability to prepare the spell required for the potion (so you cannot brew a potion if you have no available spell slots). You can use any Caster Level between the minimum required for the spell ((2 x Spell Level) - 1, usually) and your Caster Level, though it will change the price of the ingredients required. Brewing a potion consumes the spell slot the spell was prepared in, and any material component costs are added to the cost of ingredients, i.e. a potion that costs 150 gp for magical ingredients and 300 gp for its material components would cost 450 gp to brew.
Brewing potions requires the Brew Potion feat. Once a potion is brewed successfully, it lasts until it's imbided or is dispelled by other means. Potions don't have expiration dates.
In summary, to brew a potion you have to do the following:
- Have the Brew Potion feat
- Pick a spell or formula to make into a potion.
- Pay half the base price in materials. The base price is Spell Level x Caster Level x 50 gp.
- Dedicate 2 hours if the base price is less than 250 gp, or 8 hours for every 1,000 gp (minimum 8 hours).
- Make a Spellcraft or Craft (alchemy) check against a DC of 5 + Caster Level.
The typical spell for dealing with implanted eggs is Remove Disease:
The spell also kills some hazards and parasites, including green slime and others.
An example of a creature very similar to a chest burster is the Lunarma:
Implant Eggs (Ex)
As a full-round action, a lunarma can lay 2d6 eggs in a helpless creature. The eggs hatch after 24 hours and each deals 1 point of Con damage per hour as they feed on the host. After 1d2 days of eating, the larvae crawl out and find a safe place to mature into adults. A remove disease spell rids a creature of all implanted eggs or larvae, or they can be removed one at a time by using the Heal skill to treat deadly wounds.
The Lunarma record also suggests another alternative: Using the Heal skill to Treat Deadly Wounds.
Treat Deadly Wounds is also how you remove an implanted bomb:
Removing an implanted bomb requires a Heal check to treat deadly wounds, followed by a dispel magic spell or Disable Device check to neutralize the bomb (DC = 11 + alchemist's caster level).
Naturally, your DM is free to say "but mine are different."
Best Answer
No, you can't use more than one discovery on one bomb.
from Pathfinder SRD
However!
Some bomb-related discoveries stack can be used together. Take a look at the list of discoveries - the ones marked with a dot do not stack. As a rule of thumb you can have the bomb use one discovery that adds a special effect to a bomb and any number of discoveries that affect how you throw it, e.g. Acid Bomb, Inspired Bomb and Strafe Bomb can be used at the same time, but Acid Bomb and Immolation Bomb can't.