Practicum 7 DRUG DILUTION Medicinal ingredients written in prescriptions are generally written in units of: 1. Grams are usually not written in units, for example Lactosum 2 means lactosum weighs 2 grams, or there are also those who write it in full, for example Lactosum 2 grams/2 g but you cannot write 2 grams, because 1 grain = 0.06479891 grams or = 64.79891 milligrams. 2. Milligram, different from the gram unit, the milligram unit must be written clearly. Example Chlorpheniramini maleas 8 mg. 3. SI (International Unit) or UI (International Unit), drugs with this unit are usually used for medicinal substances that cannot be obtained in a pure state. this unit is the concentration of the active substance in the mixture. Example: Vitamin A 1000 UI preparations, Bacitracin 4,000,000 UI, Insulin 100 UI, Asparaginase 5000 UI, etc. 4. Microgram (mcg/ ) for example vitamin B12 20 mcg 5. Volume units: milliliters (mL), cubic centimeters (cc), micrograms (μg), microliters (μL), 1 cc = 1 mL = 1000 μL. The minimum weight of medicinal substances that can be weighed is 50 mg, if the weight is less than 50 mg then a dilution must be made. Dilution also applies to tablet/capsule preparations which are in fractional form, for example 0.6 tablets, 1/4 tablet/capsule must also be diluted. Various forms of dilution: 1. Dilution of medicinal raw materials in solid/pushed dosage forms. As an example: a. The prescription requires Chlorpheniramini maleas 30 mg, because the level is less than 50 mg, a dilution must be made. The method is to weigh: Chlorpheniramini maleas 50 mg + QS dye + Lactosum until a weight of 500 mg is obtained. The three ingredients are mixed and ground finely, stirring until homogeneous. From the mixture we take as much as =30 mg x 500 mg = 300 mg The limit on the number of dilutions to be made must depend on the number of dilutions to be taken. The principle is that the number of dilutions to be taken must be a whole number and can be weighed because the value of the dilution results, the number cannot be rounded again. b. A prescription requires 23 mg of Chlorpheniramini maleas, if you take a tablet, for example a tablet containing 4 mg of chlorpheniramini maleas.as much as = 23 mg/4 mg x 1 tablet = 5 ¾ tablets. Take 5 CTM tablets + 1 tablet for dilution. Dilution: 1 finely crushed CTM tablet is added with Saccharum lactis up to 400 mg. Amount of dilution taken = ¾ tablet x 400 mg = 300 mg. The remainder is wrapped in parchment and given an identity/information = stating the tablet content in the dilution. If the tablet is already colored during dilution, there is no need to add coloring. The remaining dilution can be written as follows: retail contains CTM at a rate of 1 CTM tablet in 400 mg dilution or 4 mg CTM/chlorpheniramini maleas in 400 mg dilution. 2. Dilution of solid medicinal substances in liquids. In making liquid medicinal preparations which contain small amounts of solid medicinal ingredients (less than 50 mg), this medicine must be diluted using the carrier/solvent contained in the composition in the prescription. Example 1. In the recipe composition above there is Vanillin as an odor corringent which weighs less than 50 mg, so it must be diluted with the solvent contained in the recipe composition, namely 90% ethanol. The dilution volume must be adjusted to the amount of solvent available. Dilution calculation: Vanillin was weighed 50 mg, dissolved in 90% ethanol to a volume of 12 mL. The resulting dilution is taken as = 25 mg x 12 mL = 6 mL 50 mg The 6 mL dilution result includes 90% ethanol which comes from the standard recipe. Example 2: Cosylan Syrup with composition: Because the weight of Ethylmorphine HCl is less than 50 mg, a dilution is made using the solvent in the Cosylan Syrup Thymi recipe. Calculation: Ethylmorphine is weighed 50 mg then dissolved in Thymi Syrup to a volume of 10 ml. The solution is taken = 30 mg/ 50 mg x 10 ml = 6 ml. 3. Dilution of liquid medicinal substances in liquid preparations. Liquid solutions in liquids, for example 70% ethanol which is a 95% alcohol solution in water. For example, 600 ml of 70% ethanol will be made, in the laboratory 95% ethanol is available, how much volume of 95% ethanol must be taken and how much aqua destillata must be added to make 70% ethanol? To complete the recipe we use the formula: P1. V1 = P2. V2 P1 = % ethanol 70% P2 = % ethanol 95% V1 = volume 70% ethanol V2 = volume 95% ethanol Solution: 70% x 500 ml = 95% x V2 V2 = Volume of water added = 500 ml -ml -> volume of 95% ethanol to be measured ml = ml 6. Multilevel dilution (in powder) Multilevel dilution is carried out when the amount of medicinal ingredients is very small, and will be mixed with other medicinal ingredients and other additional ingredients. So that the medicinal ingredients can be distributed evenly in the mixture, it is necessary to carry out multilevel dilutions. Currently, multilevel dilution is widely used in the pharmaceutical industry which produces tablets with very small levels of active substances. Example: Digoxin tablets containing 0.25 mg Digoxin. Multilevel dilutions must be carried out so that the very small amount of active substance can be distributed evenly over the large amount of tablet mass. So that patients who use this drug can get the right dose of medication. Example of a multilevel dilution calculation: for example, 0.5 mg Atropine Sulfate is needed.