What is the best formula to prepare a 5% oral hydrochloric acid solution starting from a 37% solution, and what is the standard dosage for this preparation, given that the patient must combine it with 400 mg of betaine HCl and the prescription specifies taking 2 pipettes in some water immediately after a meal?

What formula would you recommend for reproducing pre-filled 2% lidocaine gel syringes for a patient who requires large quantities for bladder catheterization and finds the commercial syringes too expensive?

Is disodium phosphate dihydrate necessary for the stability of a 250 ml lidocaine mouthwash prescription containing 200 mg lidocaine HCl, 42.5 g glycerol, 1.88 g hypromellose, 218.75 mg methylparaben, 31.25 mg propylparaben, and 250 mg sodium saccharinate, given that the TMF lidocaine HCl mouthwash formula does not include this ingredient and does not present stability issues?

What is the best base to use for preparing a BLT cream, requested by a plastic surgeon, which consists of a composition of three local anesthetics: 20% benzocaine, 6% lidocaine, and 4% tetracaine?

Is the ethanol content in 50 ml of hawthorn tincture and 50 ml of passionflower tincture sufficient to dissolve 14 g of phenobarbital, given that according to Martindale 1 g of phenobarbital dissolves in 10 g of ethanol?

What is the best alternative preservative to replace potassium sorbate in buffered cetomacrogol cream TMF (pH 5-5.5) given that potassium sorbate is currently unavailable, sorbic acid is considered unsuitable due to its activity at pH <4, and parabens can cause allergic reactions, ensuring the alternative causes the fewest problems and is sufficiently efficient?

Is it possible to prepare a rifampicin suspension with a longer shelf life for a patient requiring several months of treatment, given that the current TMF-based formulation only lasts one week, while UZ Gent uses Syrspend to achieve a 60-day shelf life but at a high cost; specifically, can a 30-day shelf life in the refrigerator be justified for a modified TMF formula using guar gum instead of xanthan gum and increased amounts of syrupus simplex and sodium saccharinate, considering the child has no issues with the taste and the preparation is consumed within 20 days?