Why must a melatonin syrup be stored in the refrigerator, how long is its shelf life, and what did HPLC stability testing of aqueous solutions at various temperatures and concentrations reveal regarding potency and sterility over a 6-month period?

In which cases should lidocaine HCl be replaced by lidocaine base, specifically considering that while lidocaine HCl is often used in oral preparations, it can cause charge interactions with viscosity enhancers, and does lidocaine base have different properties than the HCl form that would allow its use in these instances?

What is the procedure for the preparation of nitrofurantoin capsules for children?

What is the practical difference between Cetiol and Cetiol V, and which one is preferred for use?

Is the transformation of ranitidine 150 mg and acetylsalicylic acid 300 mg capsules into a brown, malleable mass caused by the absorption of moisture and the subsequent formation of acetic acid?

Does raspberry aroma reduce the effectiveness of omeprazole syrup by half?

What is the recommended preparation method and concentration for a viscous oral mucosal gel containing lidocaine and sodium bicarbonate for a cancer patient, specifically regarding the use of hydroxyethylcellulose, the necessity of heating during preparation, and the suitability of final sterilization in an autoclave since filtration is not possible?