Pharmaceutical Compounding Preparation of Syrup, Spirit and Elixir Hemin J Majeed MSc. Pharmaceutical sciences 1
Syrup Syrups: Are sweet, viscous aqueous liquids, they are concentrated aqueous preparations of sugar or sugar substitute with or without flavouring agents and medicinal substances. Medically they are divided into two types:- 1. Non medicated syrups:-(flavouring syrups): These syrups are intended to serve as pleasant tasting vehicles for medicinal substances (example cherry syrup) 2. Medicated syrups:-these contain ingredients giving them therapeutic value. (E.g. Antitussive, antihistamines).
Pharmaceutical classification of syrups according to their basic formulation 1. Sugar based syrups: These are concentrated solutions of sugar (e.g. Sucrose,dextrose). 2. Sugar free syrups: These are formulated with artificial sweetening agents.(e.g. sorbitol) The use of sucrose is preferred in the pharmaceutical preparation due to : A. It s purity B. Degree of sweetness C. Lack of color D. Ease of handling E. It s inertness.
Note : Sucrose subject to two degradative pathways: Fermentation Hydrolysis Fermentation of sucrose : Sucrose as carbohydrate in dilute solution provide nutrient media for the growth of micro-organisms.(mold, yeasts) The steps of M.O. growth include: turbidity (change in colour),(change in odour),(change in taste). The concentration of sucrose is an important factor in inhibition of mold growth, the saturated solution of sucrose if stored properly will be self preserving (contain no free water,thus they behave as anhydrous media with respect to growth of M.O and this will lead to shrinkage and lyses of M.O.
Preservatives which are suitable for use in syrups: benzoate, parapens, mixture of methyl parapen and butyl parapen. In some syrups alcohol present in small amount (not more than 10%) which serve as solubilizing agent for alcohol soluble ingredient
Hydrolysis of sucrose Sucrose is disaccharide and can be hydrolysed to give monosaccharides (dextrose (glucose), fructose(levulose) The hydrolytic reaction is acid specific (i.e. hydrogen ion act as a catalyst)this reaction called inversion. The invert sugars (dextrose, fructose) have specific properties: They are fermented more easily than sucrose They are sweeter than sucrose Degradation of laevulose (which is formed by inversion )is responsible for brown color of some colourless syrups. This change called caramelization,this phenomena is take place in syrup containing acids. Storage of syrup Generally syrups are stored at room temperature, in tightly stoppered well filled bottles,saturation and refrigeration will inhibit both mould growth and inversion, but less than 4 C will cause crystallization (large crystals difficult to redisolved.)
Preparation of simple syrup Simple syrup B.P Rx Sucrose 667 g D.W Q.S 1000 g Method : 1. Weigh the beaker empty and weigh the sucrose in it 2. Add small quantity of water with stirring to dissolve the sucrose on gentle heating (using water bath). 3. Weigh again to complete the weigh by hot water Simple syrup U.S.P. Rx Sucrose 850 g D.W Q.S 1000 ml Methods : Prepare by using boiling water
Dextrose based syrup dextrose is used instead of sucrose in syrups containing strong acids to prevent caramelization. Differences between sucrose and dextrose 1. The saturated solution of dextrose is 70%, so the dextrose based syrup susceptible to the growth of micro-organism, therefore we must add preservative. 2. Dextrose dissolve more slowly than sucrose. 3. The sweetness of dextrose is less than the sweetness of sucrose.
Sugar free syrup (non - nutritive syrup) Sugar free syrup: it is called artificial syrup,this type of syrup given to patients suffering from diabetes mellitus. General formula of non-nutritive syrups. Sweetening agent : sorbitol, saccharine, aspartame. Viscosity builder: carboxy methyl cellulose (CMC), Sodium alginate. Preservative : benzoic acid, sodium benzoate. Purified water.
Sorbitol based syrup Sorbitol has the following properties: Used in non nutritive syrups for diabetic patient (not cause hyperglycemia). Not cause dental carries. Sorbitol is 60 % as sweet as sucrose. Have a good taste. Not need preservative if it is concentration is more than 60%. Chemically stable. Not absorbed from GIT as rapid as sucrose. Not irritating to the mouth and throat membrane. Has a laxative effect if ingested in large quantity. Has half the viscosity of simple syrup.
Sorbitol solution U.S.P Rx Sorbitol 70 g D.W 100 g Method by simple solution method Chloral hydrate syrup ( U.S.P) official Rx Chloral hydrate 0.5 g Simple syrup Q.S 100 ml Ft. mist Sig. F ss o.n Method : Dissolve chloral hydrate in 75 ml of simple syrup, stir well, filter then complete the volume of filtrate to 100 ml by simple syrup. Chloral hydrate syrup (non-official ) Chloral hydrate 0.5 g Sorbitol 70 g D.W Q.S 100 ml Method : 1. Dissolve chloral hydrate syrup and sorbitol in 75 ml of water. 2. Stir well to enhance solubility. 3. Strain by cotton. 4. Complete the volume to 100 ml by D.W.
Elixir
Elixirs Are clear, sweetened, hydroalcoholic solutions intended for oral use, and are usually flavoured to enhance their palatability. Medically they are classified to: 1-non medicated elixirs: this employed as vehicles for medicinal substances. Ex: elixir of glyceriza 2-medicated elixirs: this contain ingredient giving them therapeutic value. Ex: bronchicum elixir
Notes Varies proportion of alcohol can be used in elixir preparation because of different water and alcohol solubility characteristics of components(each elixir require a specific blend of alcohol and water to maintain all of components in solution) In addition of alcohol and water other ingredients may be used in elixirs such as: 1-Glycerin and propylene glycol which used as adjunct solvents. 2-sucrose, saccharine, and sorbitol as a sweetening agent. 3-flavoring materials to increase their palatability. 4-couloring agents to enhance their appearance. Elixirs containing over 10-12% of alcohol are usually self preserving. Elixirs should be stored in tight, light resistant containers and protected from excessive heat because of their usual content of volatile oils and alcohol.
Differences between elixirs and syrups: 1-elixirs are usually less sweet and less viscous than syrups because they contain a lower proportion of sugar and consequently are less effective than syrups in masking the taste of medicinal substances. 2-elixirs are better able than aqueous syrups to maintain both water soluble and alcohol soluble components in solution because of their hydroalcoholic character. 3-from a manufacturing stand point, elixirs are preferred over syrups due to their stability and ease of preparation (by simple solution).
Preparation of elixirs: Elixirs are usually prepared by simple solution with agitation and /or by the admixture of two or more liquid ingredients. Alcohol-soluble and water- soluble components are generally dissolved separately in alcohol and in purified water, respectively. Then the aqueous solution is added to the alcoholic solution rather than the reverse, in order to maintain the highest possible alcoholic strength at all times so that minimal separation of the alcohol-soluble components occurs. When the two solutions are completely mixed the mixture is made to volume with the specified solvent or vehicle.
Note: In preparation of elixirs frequently the final mixture will not be clear (cloudy) due to separation of some of the flavouring oils by reduced alcoholic concentration. If this occurs, the elixir is usually permitted to stand for number of hours, to ensure the saturation of hydroalcoholic solvent and to permit the oil globules to coalesce so that they may be more easily removed by filtration.
Comparison between elixirs and spirits:
spirits Spirits are alcoholic or hydroalcoholic solution of volatile substances. Generally, the alcohol concentration of spirits is rather high, usually over 60%. Because of the greater solubility of aromatic substances in alcohol than in water. There is small number of spirits Some have therapeutic effect, other are used as flavor Each spirit has its own method for preparation
Uses of Spirits: Spirits may be used pharmaceutically as flavoring agent and medicinally for the therapeutic value of aromatic solute. As flavoring agents they are used to impart the flavor of their solute to other pharmaceutical preparations. For medicinal purposes, spirits may be taken orally, applied externally, or used by inhalation, depending upon the particular preparation. When taken orally, they are generally mixed with a portion of water to reduce the pungency of the spirit.
Peppermint spirit Dissolve the peppermint oil in ethanol (90%) and add sufficient ethanol (90%) to produce 1000mL. If the solution is not clear, shak with previously sterilized Purified Talc and filter. Peppermint oil is an aromatic carminative that relaxes gastrointestinal smooth muscle and relieves flatulence and colic
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