All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is sufficient in making up for the prayers that you had missed, to make them up in order: you make up the Fajr, then the Thuhr, then the ‘Asr, then the Maghrib, and then the ‘Isha prayer; and again you do the same thing [every day after every obligatory prayer].
The view we adopt here in Islamweb is that the order about missed prayers is desirable but not obligatory.
It is sufficient for you in making the intention for a missed prayer, to determine which obligatory prayer that you are making up, Fajr or Thuhr,…etc. You do not have to determine the ninth, or the tenth prayer, or to pray the prayer of such and such day.
“If a person has one missed prayer, or many missed prayers, then there is no difference of opinion that it is not a condition for him to intend the Thuhr of Thursday, for example; rather, it is enough to make the intention of praying the Thuhr prayer, or the missed Thuhr prayer if we condition the intention of making up for a missed prayer.” [End of quote]
The footnote of ash-Shirwani on at-Tuhfah reads:
“It is not desirable to mention the day, or the month, or the year according to the reliable opinion...” [End of quote]
Your saying that: “I am making up my ninth Fajr prayer” etc when it reality was the 10th”, then if this is a slip of the tongue only while you made the intention of making up for the tenth day, then there is no problem at all in this. What is important is the intention and not what the tongue has uttered (by mistake).
If you had really intended to make up for the ninth day while in reality you had already made up for the Fajr of that day, then this prayer that you made up is not sufficient for making up for the tenth day.
“If he intended in the prayer to make up for the Thuhr of Monday, while he had to make up for the Thuhr of Tuesday, then this is not sufficient for him; this is explicitly stated by al-Baghawi.” [End of quote]
However, some scholars hold the view that it is sufficient for him because he singled out what he is not obliged to single out.
Ar-Ramli from the Shaafi'i School of jurisprudence was asked about those who had to make up for the Thuhr of Wednesday only, but they prayed Thuhr while intending making up for the Thuhr of Thursday mistakenly, so does it take place as the Thuhr of Wednesday because he singled out what he is not obliged to single out, and he was mistaken in it; like if he was mistaken about the Imam [i.e. he intended to imitate a given Imam and it came out that it is another Imam] and in the funeral prayer [i.e. when intending the funeral prayer on a particular deceased while it came out that it is a funeral of another dead person] or not?
He replied: “It takes place for what he had intended [i.e. for Wednesday] for what has been mentioned, as determined by the statements of the two Shaykhs [from the Shaafi’i School], and other scholars, even though some of them held another view.” [End of quote]
As for the sale of alcohol-containing medicines, then we mentioned in a Fatwa in the Arabic Site, that the Islamic Fiqh Academy stipulated that it is permissible to use alcohol-containing medicines at consumable rates required by the pharmaceutical industry, which is irreplaceable. We also mentioned that the transformation of alcohol or gelatin during manufacturing to another substance, then the ruling about it differs according based on the view that the impurity becomes pure when it is transformed. In addition, if it is little and its effect does not appear in the color of the medicine, nor its taste, nor its smell, then there is nothing wrong in using it. Moreover, the fact that some medicines contain a kind of a pure prohibition, although in principle it is forbidden, it is permissible to use it if there is no other permissible alternative that can be used instead. Since using some of such medicines sometimes is permissible, then it becomes also permissible to sell them.
Based on the above, we do not see any harm on you about the above mentioned job.
Allah knows best.