Syrups & Elixirs

1. Syrups & Elixirs Dr.M.Shakil.S.Siddiqui

2. Definition • Syrups consist of sugar in water. These are highly concentrated, and viscous preparations. • In simple syrup sucrose at the concentration of 85% is dissolved in water. • If some therapeutic agent is present, then it is called as medicated syrup.

3. Flavoured Syrup • Some syrups does not contain therapeutic agent, instead they consists of flavouring agents. These are called flavoured syrups and are generally used as vehicles. • These are of advantageous as they contain very less amount or no alcohol, it can be administered to small children. But patients who have to take food having less calories should be aware of amount of sugar present in liquid orals

4. Effect of concentration on various factors is as follows: • If the solution is saturated and if the temperature decreases, it results in the crystallization.  • The sugar solution should be nearly to saturation point, but should not be saturated.  • The solution at low concentration flavors the growth of moulds but at higher concentration stops the growth of organism. 

5. Details of Viscosity • The viscosity of a fluid is a measure of its resistance to gradual deformation(flow) by shear stress or tensile stress. • For liquids, it corresponds to the informal notion of "tViscosity is due to friction between neighboring parcels of the fluid that are moving at different velocities. • When fluid is forced through a tube, the fluid generally moves faster near the axis and very little near the walls, therefore some stress (such as a pressure difference between the two ends of the tube) is needed to overcome the friction between layers and keep the fluid moving. For the same velocity pattern, the stress is proportional to the fluid's viscosity. hickness". For example, honey has a higher viscosity than water

6. Ideal Fluid • A fluid that has no resistance to shear stress is known as an ideal fluid or inviscid fluid. In the real world, zero viscosity is observed only at very low temperatures, in superfluids. • Otherwise all fluids have positive viscosity. If the viscosity is very high, such as in pitch, the fluid will seem to be a solid in the short term. In common usage, a liquid whose viscosity is less than that of water is known as a mobile liquid, while a substance with a viscosity substantially greater than water is simply called a viscous liquid.

7. What is viscosity? • What is viscosity?This question is often best answered by example. Imagine a styrofoam cup with a hole in the bottom. If I pour honey into the cup I will find that the cup drains very slowly. That is because honey's viscosity is large compared to other liquids' viscosities. If I fill the same cup with water, for example, the cup will drain much more quickly.

8. Measurement of Viscosity • Viscosity is measured with various types of viscometers and rheometers. • A rheometer is used for those fluids that cannot be defined by a single value of viscosity and therefore require more parameters to be set and measured than is the case for a viscometer. Close temperature control of the fluid is essential to acquire accurate measurements, particularly in materials like lubricants, whose viscosity can double with a change of only 5 °C.

9. Fluidity • The reciprocal of viscosity is fluidity, usually symbolized by φ = 1 / μ or F = 1 / μ, depending on the convention used, measured in reciprocal poise (cm·s·g−1), sometimes called the rhe. Fluidity is seldom used in engineering practice.

10. Elixirs • An elixir is a liquid oral preparation that usually contains either potent or unpleasant-tasting drugs. The formulation is clear and generally contains a high proportion of sugar or other sweetening agent, included to mask offensive or nauseating tastes. • Paediatric elixirs are usually formulated with a fruit syrup as a base flavoring agent. • In general, non-aqueous solvents (alcohol, glycerin or propylene glycol) form a significant proportion of the vehicle used in elixirs, or alternatively solubilising • agents are included.

11. Elixirs • In general, non-aqueous solvents (alcohol, glycerin • or propylene glycol) form a significant proportion of • the vehicle used in elixirs, or alternatively solubilising • agents are included. • Ingredients: • Alcohol •  Water •  Glycerin  • Preservatives •  Sorbital •  Flavouring agents  • Elixirs have low viscocity than syrups and they can flow more freely as there will be very less use of agents that increase viscocity like sucrose.

12. Types of Elixirs • Non-medicated elixirs • They are used as solvents or vehicles for the preparation of medicated elixirs: aromatic elixirs (USP), isoalcoholic elixirs (NF), or compound benzaldehyde elixirs (NF). Active ingredient dissolved in a solution that contains 15 to 50% by volume of ethyl alcohol • Medicated elixirs • Antihistaminic elixirs: used against allergy: chlorampheniramine maleate elixirs (USP), diphenhydramine HCl elixirs. • Sedative and hypnotic elixirs: sedatives induce drowsiness, and hypnotics induce sleep: pediatric chloral hydrate elixirs. • Expectorant: used to facilitate productive cough (cough with sputum): Terpin hydrate elixirs. • Miscellaneous: acetaminophen (paracetamol) elixirs, which are used as analgesics.