How to mix the ingredients. If there are more than two ingredients in a medicinal preparation, the mixing must be done as well as possible to obtain a homogeneous mixture. There are several mixing methods, namely: - Spatula. The ingredients are crushed on the paper using a spatula. This method produces less than optimal results, especially if a large amount of powder is mixed. - Trituration. The ingredients are crushed in a porcelain mortar or wooden mortar, you can also use a glass mortar. Preferably a porcelain mortar with a rough inner surface. The results obtained are quite good. Currently, this method is the most commonly used in pharmacies and laboratories.(Trituration is the process of grinding the drug in a mortar to refine/reduce the particle size). - Sieve. The ingredients are mixed by passing them through a sieve. The mixture obtained is usually quite smooth. This method is less reliableits homogeneity. - Tumbling. The ingredients are rolled around so that they are mixed evenly. This method is used to mix large amounts of powder, using a specially designed powder grinding machine. Apart from that, the method of mixing medicinal ingredients and additional medicinal ingredients must be in accordance with the physico-chemical properties of each ingredient.Some medicinal ingredients will show undesirable reactions when mixed, for example clumping, color changes or other reactions that will cause a decrease or loss of the efficacy of the medicinal ingredients. The following are guidelines for mixing medicinal ingredients: 1. Solid dosage form. -If a clumping reaction occurs between the medicinal ingredients, then before mixing, each medicinal ingredient is first coated with additional ingredients. Example: If Salicylic Acid and Zinc Oxide are mixed directly, they will harden over time, so before the two are mixed, each is first coated with additional ingredients. - If there is a crystal form of medicinal substance in the preparation, dissolve it first with a suitable solvent. Example: Salicylic Acid, it must be dissolved first in 95% Ethanol, then immediately mixed with additional ingredients until dry. - If there are medicinal ingredients that are hygroscopic (easily damp), then they are crushed in a hot mortar/mortar to evaporate the water contained in the medicinal ingredients. -If there is a medicinal substance that is a eutectic mixture, that is, a mixture whose melting point is lower than if the substance were standing alone, for example Camphora and Mentholum, then let the mixture melt first, then dry it with additional ingredients. -If there are medicinal ingredients in the form of essential oils, add them last so they don't get crushed for too long because essential oils are very easy to evaporate 2. Semi-solid dosage form. How to mix medicinal ingredients and additional medicinal ingredients is guided by the 4 general rules for making ointments. 3. Liquid dosage form. - Solution dosage form: the medicinal substance is dissolved in a solventto taste, then add the remaining solvent to the required volume or weight. - Suspension dosage form: the insoluble medicinal substance is mixed with the suspension material, then the solvent is added in a predetermined volume until a suspension is formed, after which it is mixed with the remaining solvent to the required volume or weight. - Emulsion dosage form: first make an emulsion corpus, then mix it with the medicinal substance and add the remaining solvent to the required volume or weight.