Could you provide advice regarding the preparation and shelf life of a sterile 1% calcium gluconate eye wash, which has been requested by a company for use in the event of a potential accident involving hydrofluoric acid (HF)?

Since Timolol 0.25% eye drops (Timabak 0.25%) are no longer commercially available, is it permissible to prepare Timolol 0.25% eye drops starting from Timabak 0.5% by using water for injection and a filter, and would the buffer remains sufficient in this case?

How much methylcellulose 400 should be used instead of methylcellulose 1000 in the methylcellulose gel FN 6 formula, which currently specifies methylcellulose 1000, given that it is temporarily unavailable and the goal is to achieve the same viscosity?

Given that the authors Wolf and Sürüp state that erythromycin is inactivated within 1 to 3 hours at pH 6, would cetomacrogol cream buffered at pH 5 be unsuitable for use?

How can a specialist ORL's request to prepare a 10 ml middle ear solution containing 40 mg/ml gentamicin in a physiological buffer at pH 6.5 be achieved, given that dissolving gentamicin in the specified buffer of 1.54 g boric acid and 60 mg borax per 100 ml results in a pH drop to approximately 5?

How can the absence of nifedipine as a bulk product be resolved for a preparation of 60 capsules containing 2.5 mg of nifedipine, given that nifedipine bulk powder is no longer available and existing specialties consist of oil capsules or retard formulations?

How can the recurring precipitation be resolved in a preparation containing 60 drops of ammoniated anise solution, 80 mg of promethazine HCl, 1.5 g of sodium benzoate, 30 g of tolu syrup, and equal parts of raspberry syrup and water up to a total volume of 300 ml?