Oral Solutions - PDF

Solutions  Definition: In pharmaceutical terms, solutions are “liquid preparations that contain one or more chemical substances dissolved in a suitable solvent or mixture of mutually miscible solvents”.  Classification of solutions: On the basis of the...

Solutions  Definition: In pharmaceutical terms, solutions are “liquid preparations that contain one or more chemical substances dissolved in a suitable solvent or mixture of mutually miscible solvents”.  Classification of solutions: On the basis of their use, they are classified as 1. oral, 2. otic, 3. ophthalmic, or 4. topical solutions. On the basis of their composition, they may be classified as other dosage forms. For example, 1. aqueous solutions containing a sugar are classified as syrups (even though some syrups may contain some alcohol), 2. Sweetened hydro alcoholic (combinations of water and ethanol) solutions are termed elixirs, and 3. Solutions of aromatic materials are termed spirits if the solvent is alcoholic. 4. Solutions of aromatic materials are termed aromatic waters if the solvent is aqueous. 5. Solutions prepared by extracting active constituents from crude drugs are termed tinctures or fluidextracts, depending on their method of preparation and concentration.  Tinctures may also be solutions of chemical substances dissolved in alcohol or in a hydro alcoholic solvent. 6. Certain solutions prepared to be sterile and pyrogen free and intended for parenteral administration are  Preparation of oral solutions: Methods of preparation of solutions fall into three main categories; 1. Simple solution method: Solutions of this type are prepared by dissolving the solute in most of the solvent, mixing until dissolved, then adding sufficient solvent to bring the solution up to the proper volume. The solvent may contain other ingredients that stabilize or solubilize the active ingredient Examples of solutions made by this method are Calcium hydroxide topical solution USP (lime water), sodium phosphates oral  Contd. 2. Solution by chemical reaction: These solutions are prepared by reacting two or more solutes with each other in a suitable solvent. e.g., Aluminum sub acetate topical solution USP. 3. Solution by Extraction: Vegetables or animal origin are often extracted with suitable solvent. Preparation of this type may be classified as solutions but more often termed as EXTRACTS e.g., Extract of Belladonna.  Components of oral solutions: Most solutions intended for oral administration contain following ingredients besides solute and solvent: 1. Flavorants to mask taste of bitter or nauseous drugs 2. Colorants to make the medication more attractive and palatable. 3. When needed, they may also contain stabilizers to maintain the chemical and physical stability of the medicinal agents 4. Preservatives to prevent the growth of microorganisms in the solution.  Dose of solutions: Liquid pharmaceuticals for oral administration are delivered in doses of 5 ml (one teaspoonful), 10 ml (2 teaspoonful), or 15 ml (one tablespoonful). A few solutions have large doses, for example, Magnesium Citrate Oral Solution, USP, with a usual adult dose of 200 ml, is used as saline cathartic. On the other hand, many solutions for children are given by drop with a calibrated dropper in the product package.  1. Dry mixtures for solution A number of medicinal agents, particularly certain antibiotics, e.g., penicillin V, have insufficient stability in aqueous solution to meet extended shelf-life periods. Thus, commercial manufacturers of these products provide them to the pharmacist in dry powder or granule form for reconstitution with a prescribed amount of purified water immediately before dispensing to the patient.  Components of dry mixtures: The dry powder mixture contains all of the formulative components, including drug, flavorants, colorant, buffers, and others, except for the solvent.  Shelf life: Once reconstituted by the pharmacist, the solution remains stable when stored in the refrigerator for the labeled period, usually 7 to 14 days, depending on the preparation. This is a sufficient period for the patient to complete the regimen usually prescribed. However, in case the medication remains the medicine should be discarded.  Examples: Examples of dry powder mixtures intended for reconstitution to oral solutions are the following: 1. Cloxacillin Sodium for Oral Solution, USP, an anti-infective antibiotic 2. Penicillin V Potassium for Oral Solution, USP an anti-infective antibiotic 3. Potassium Chloride for Oral Solution, USP a potassium supplement  2- Oral Rehydration Solutions (ORS): Rapid fluid loss associated with diarrhea can lead to dehydration and ultimately death in some patients, particularly infants. During diarrhea, the small intestine secretes far more than the normal amount of fluid and electrolytes and this simply exceeds the ability of the large intestine to reabsorb it. This fluid loss, can lead to a progressive loss of blood volume resulting in hypovolemic shock. The loss of fluid during diarrhea is  A liter of typical oral rehydration solution contains 45 mEq Na+, 20 mEq K+, 35 mEq Cl−, 30 mEq citrate, and 25 g dextrose. Examples of Commercial ready-to- use oral electrolyte solutions include Pedialyte Solution and Rehydralyte Solution (Ross). These products also contain dextrose or glucose. Infalyte Oral Solution (Bristol- Myers Squibb) contains electrolytes in a syrup of rice solids.  3-Oral Colonic Lavage Solution: Traditionally, preparation of the bowel for procedures such as a colonoscopy consisted of 1. administration of a clear liquid diet for 24 to 48 hours preceding the procedure, 2. administration of an oral laxative such as magnesium citrate or bisacodyl the night before, and 3. a cleansing enema administered 2 to 4 hours prior to the procedure.  Consequently, an alternative method to has been devised. This new procedure requires less time and dietary restriction and eliminates the need of cleansing enemas. This method uses oral administration of oral colonic lavage solution (a balanced solution of electrolytes with polyethylene glycol i.e., PEG-ES). Before procedure, the pharmacist reconstitutes this powder with water, creating an iso-osmotic solution having a mild salty taste.  The formulation of oral colonic lavage solution is as follows: PEG-3350 = 236.00 g Sodium sulfate = 22.74 g Sodium bicarbonate = 6.74 g Sodium chloride = 5.86 g Potassium chloride = 2.97 g In 4,800 ml disposable container. The product must be stored in the refrigerator after reconstitution. The recommended adult dose of this product is 4 L of solution before the gastrointestinal procedure. Directions for use: The patient is instructed to drink 240 mL of solution every 10 minutes until about 4 L is consumed allowing the patient 3 hours for drinking and a 1-hour waiting period to complete bowel evacuation. The patient is advised to drink each portion quickly rather than sipping it continuously. Usually, the first bowel movement will occur within 1 hour. Caution: Ideally, the patient should not have taken any food 3 to 4 hours before beginning to take the solution. In no case should solid foods be taken by the patient for at least 2 hours before the solution is administered.  Reference: Ansel’s pharmaceutical dosage forms and drug delivery systems https://www.babygaga.com/ pedialyte-facts-parents-babies/