有關胃藥active ingredient

胃藥個active ingredient其實應該係magnseium hydroxide又或者aluminium hydroxide...
大多數胃藥都離唔開呢兩種, 因為胃藥係要中和胃部既酸性...所以個active ingredient一定係alkaline既野...但有d胃藥會加solid acid, 咁係唔好俾d alkaline中和晒所有acid, d solid acid可以補充番失去左既acid, 令個胃舒服d咁姐.......隨左citric acid, 仲會加左starch, 不過呢d唔係active ingredient.....
有d胃藥既ingredient係 magnesium carbonate會出好多gas, 如果胃藥既ingredient係carbonate, 食左之後會有胃氣, 令胃部唔舒服, co2係by-product黎既
MgCO3 + 2HCl出MgCl2, CO2, 同H2O
NaHCO3 + HCl出NaCl, CO2,同H2O
含有hydroxide, e.g magnesium hydroxide會有輕瀉作用, 但aluminium hydroxide就會令人便秘.....
要搞清楚一點就係active ingredient意思係指"有效成分", 通常用化學物質佔一粒藥丸幾多個percentage黎定, 所以胃藥既active ingredient只係指carbonate/hydroxide, 唔係一d中和唔到胃酸既chemical e.g citric acid/starch

2006-11-21 16:39:01 補充：
citric acid雖然係weak acid, 但你夠唔夠膽話citric acid 個pH值唔低????無錯citric acid係weak acid, 咁只係代表佢殺唔到菌, 唔代表佢唔係acidic woo

2006-11-21 16:41:44 補充：
Na2CO3係鹼性Na2CO3 HCl出NaHCO3NaHCO3再同HClreact出NaCl, CO2,同H2O

2006-11-24 11:35:59 補充：
1. 又或者我咁講, d alkaline溶左落水之後有d會同ca react左先, 咁會冇咁多alkaline同胃酸react, 你又可能會問: 咁alkaline個份量唔好俾咁多, 咁咪唔使用到ca law.其實係唔同人有唔同既胃酸concentration, 我地要照顧一d胃酸分泌冇咁多人ga ma, 有d人一粒pill都多得濟, 咁ca都會幫到手.如果胃酸太多, 中和之後都應該回復到正常水平, 如果有ca仲未react晒, 咁咪當vitamin c 咁黎吸收law, ca對人體無害, 唔須要border個ca有咩用

2006-11-24 11:36:12 補充：
2. 我諗上面答左你.但其實藥廠係唔會將alkaline個concentration較到剛好react晒所有acid ga3. yes..你想胃氣漲抑或便秘??答案好明顯但因為冇其他如肚瀉的副產品??carbonate唔會引起便秘或肚瀉, NaCl同MgCl都係salt, 會被吸收, 你睇番條equation

但放出CO2係副產品定係特登?
放出CO2係副產品
因為胃藥,要有alkaline for neutralize 胃酸,but as you know the tablet of the 胃藥 is a hard solid and the total surface area is comparatively small, if the tablet can be broken into very tiny pieces the total surface area is very large and this can make the reaction of nuetralization much faster........ and if the tablet contact water the gasing effect of citric acid and sodium hydrogen carbonate can make this happen.......
By the way, citric acid is a weak acid(compare with your stomach fluid), it cannot enhanced the acidity in this case.......