Download and Preview : Liquid Dosage Form
Report CopyRight/DMCA Form For : Liquid Dosage Form
Liquid Dosage Liquid Dosage Forms Solution solutions are clear Liquidpreparations containing one or moreactive ingredients dissolved in a suitable. Suspension Solid in Liquid dispersion Liquid preparations containing one ormore active ingredients suspended in asuitable vehicle Emulsion Liquid in Liquid dispersion .Emulsions are two phase system inwhich one liquid is dispersed throughout another liquid in the form of small particlesColloids A system in which finely divided.particles which are approximately lessthan 1 m in size are dispersed within acontinuous medium in a manner thatprevents them from being filtered easily or settled rapidly. Solutions areDosage forms prepared by dissolvingthe active ingredient s in an aqueous or non aqueous solvent Solutions can be formulated for different.routes of administrationOrally Syrups elixirs drops In mouth and throat Mouth washes gargles throat sprays In body cavities Douches enemas ear drops. nasal sprays On body Surfaces Collodions lotions Advantages of SoIutions Easier to swallow therefore easier for 1 children old age unconscious people. More quickly effective than tablets and capsules 2 Homogenous therefore give uniform dose than 3 suspension or emulsion which need shaking Disadvantages of SoIutions Bulky therefore difficult to transport and store 1 . Unpleasant taste or odours are difficult to mask 2 Needs an accurate spoon to measure the dose 3 Less stable than solid dosage forms 4 major signs of instability colour change.precipitationmicrobial growthgas formation AdditivesTo resist any change in pH.Isotonicity modifiers Solutions for injection Application to mucous membrane Large volume solutions for ophthalmic application Most widely used isotonicity modifiers are dextrose. Additives cont Viscosity enhancement It is difficult for aqueous based topical solutions to remain on the skin or in the eye why therefore low concentrations of jelling.agents are added to increase the viscosity of the product Additives cont Preservatives Solution may become contaminated for a number. of reasonsRaw materials used in the manufacture of 1solutions are excellent growth media for bacterialsubstances such as gums dispersing agents sugars and flavors. Additives Preservatives cont Equipment environment and personnel 2 contribute to product contaminationConsumer use may result in the introduction 3 of microorganism. a preservative should be added to the Additives Preservatives cont Preservative used should beEffective against a wide spectrum of 1microorganisms.Stable for its shelf life 2Non toxic non sensitizing 3Compatible with the ingredients in the dosage 4Free of taste and odour 5 Additives Preservatives cont .Preservatives may be used alone or in combination to prevent the growth of microorganismsAlcohols 1Ethanol is useful as a preservative when it is used as asolvent It needs a relatively high concentration 10 . to be effectivePropylene glycol also used as a solvent in oral solutions andtopical preparations It can function as a preservative in the range of 15 to 30 It is not volatile like ethanol Additives Preservatives cont .Benzoic acid and sorbic acid have low solubility They are used in a concentration range from 0 1 to 0 5 Only the non ionized form is effective and therefore its use is restricted to preparations. with a pH below 4 5 WHY Additives Preservatives cont Parabens are esters methyl ethyl propyl and butyl of para hydroxybenzoic acidThey are used widely in pharmaceutical products and are . effective and stable over a pH range of 4 to 8They are employed at concentrations up to about 0 2 Frequently 2 esters are used in combination in the same preparation WHYTo achieve a higher total concentration 1. To be active against a wider range of microorganisms 2 Additives Preservatives cont Quaternary Ammonium Compounds 4Benzalkonium chloride is used at a relatively low concentration 0 002 to 0 02 .This class of compounds has an optimal activity over the pH range of 4 to 10 and is quite stable at most temperaturesBecause of the cationic nature of this type of preservative it is incompatible with many. anionic compounds Additives cont AntioxidantsVitamins essential oils almost all fats and oils can be oxidized Oxidation reaction can be initiated by.heat maintain oxidizable drugs in a cool place 1light use of light resistant container 2heavy metals e g Fe Cu effect of trace metals can be 3minimized by using citric acid or ethylenediamine tetra acetic acid EDTA i e sequestering agent.Antioxidants as propyl octyl esters of gallic acid tocopherols or vitamin E sodium sulfite ascorbic acid vit C can be used Additives cont Sweetening agents.Sucrose is the most widely used sweetening Advantages Colourless highly water soluble stable over a wide pH range 4 8 increase theviscosity masks both salty and bitter taste has soothing effect on throat.Polyhydric alcohols sorbitol mannitol and glycerol possess sweetening power and can be used for diabetic preparations Additives cont Flavours and perfumes.Mask unpleasant taste or odour Enable the easy identification of the product Natural products fruit juices aromatic oil peppermint lemon Artificial perfumes are cheaper more readily .available and more stable than natural Stability of solutionsBoth physical and chemical stability ofsolutions in their containers is veryA solution must retain its clarity .colour odour taste and viscosity over its shelf life Classification of Solutions According toAqueous solutions a Non aqueous solutions b . Aqueous SolutionsAqueous solutions are homogeneousmixtures that are prepared by dissolving asolid liquid or gas in an aqueous medium vehicle .Vehicle This may be water aromatic water or extractsWater is used both as vehicle and as a solvent for the desired flavoring or medicinal ingredientsAdvantages Tasteless odourless lack of pharmacological. activity neutral and very cheapIt is not permitted to use tap water for the dispensing ofpharmaceutical dosage forms due to its possible bacterialcontamination and the presence of dissolved salts that destroy the active ingredients or enhance their decomposition.Freshly Boiled and Cooled WaterBoiling is seldom used to destroy vegetative bacteria But on storage for long time spores may yield vegetative microorganism Purified WaterMust be used for most pharmaceutical . operations and in all the tests and assaysSuch water is prepared by distillation deionization or reverse osmosisHard waters are those that contain the Ca and Mg cations.Alkaline waters are those that contain bicarbonates as the major impurityUltraviolet energy heat or filtration Millipore filtration can be used to remove or kill the microorganisms present in the water. Aromatic WatersAromatic waters medicated waters are clear saturated aqueous solution of volatile oils or other aromatic or volatile substancesThey are used principally as flavored or perfumed .Volatile oils solutions represent an incompatibility problem of salting out This occurs after theincorporation of a very soluble salt in their Aromatic Waters cont Aromatic water will deteriorate with time therefore .should be made in small quantities protected from intense light and excessive heat by storing in air tight light resistant containersIf they become cloudy or otherwise deteriorate they should be discarded Deterioration may be due to. volatilization decomposition or mould growth Aromatic Waters cont There are 2 official methods of preparation Distillation process Stronger Rose a Adv most satisfactory method .Dis slow and expensive The drug should be coarsely ground and mixed with sufficient quantity of purified water in the distillation unitAfter distillation any excess oil in the distillate is . removed by filtration Aromatic Waters cont Drug should not be exposed to the action of direct heat during distillation otherwise theodour of the carbonized substance will be. noticeable in the distilled aromatic waterIf the volatile principle in the water are present in small quantities the distillate is returnedseveral times to the still with fresh portions of Aromatic Waters cont .Solution process Peppermint water b Aromatic water may be prepared by shakingvolatile substance with purified water Themixture is set aside for 12 hours filtered Talc inert may be used to increase the.surface of the volatile substance insure morerapid saturation of the water and act as a filter Methods of Preparation ofSimple Solution a Solution by Chemical Reaction b .Solution by Extraction c Methods of Preparation of SolutionsSimple Solution a Solutions of this type are prepared by dissolving the solute in a suitable solvent by stirring or heating .The solvent may contain other ingredients which stabilize or solubilize the active ingredient e g solubility of Iodine is 1 2950in water however it dissolves in presence of KI due theformation of more soluble polyiodides KI I2 KI 2I2 KI3 I3 KI 4I4 Strong Iodine Solution USP Lugol s SoIution . Solution by Chemical Reaction b These solutions are prepared by reacting two ormore solutes with each other in a suitablesolvent e g Calcium carbonate and lactic acid used to prepare Calcium lactate mixture.Calcium lactate used to treat calcium deficiencies Solution by Extraction c Plant or animal products are prepared bysuitable extraction process Preparations of.this type may be classified as solutions but more often are classified as extractives Pharmaceutical SolutionsAqueous Sweet or Viscid NonaqueousDouches 1 Syrups 1 Elixirs 1.Enemas 2 Honeys 2 Spirits 2Gargles 3 Mucilages 3 Collodions 3Mouthwashes 4 Jellies 4 Glycerins 4Nasal washes 5 Liniments 5Juices 6 Oleo Vitamin 6.Otic solutions 8Inhalations 9Douche is an aqueous solution which is directed against a part or into a cavity of the body It functions as a cleansing or antiseptic agent .Eye douches are used to remove foreign particles and discharges from the eyes It is directed gently at an obliqueangle and is allowed to run from the inner to the outer corner of Douches cont Pharyngeal douches are used to prepare the .interior of the throat for an operation and to cleanse it in supportive conditions Similarly there are nasal and vaginal douches Douches most frequently dispensed in the form of a powder with directions for dissolving in a. specified quantity of water These preparations are rectal injections employed to Evacuate the bowel evacuation enemas 1 Influence the general system by absorption retention 2 enemas e g nutritive sedative.Affect locally the site of disease e g anthelmintic 3 They may contain radiopaque substances for 4 roentgenographic examination of the lower bowel Enemas cont Retention enemas are used in small quantities . about 30ml and are thus called retention microenemaStarch enema may be used either by itself or as a vehicle for other forms of medicationGargles are aqueous solutions frequently containing antiseptics .antibiotics and or anesthetics used for treating the pharynx throat and nasopharynx by forcing air from the lungs throughthe gargle which is held in the throat subsequently the gargle is expectorated Gargles cont .Many gargles must be diluted with water prior to use Although mouthwashes are consideredas a separate class of pharmaceuticals manyare used as gargles either as is or diluted withThe product should be labeled so that it .cannot be mistaken for preparations intended for internal administration MouthwashesMouthwashes can be used for therapeutic cosmetic purposesTherapeutic mouthwashes can be formulated to reduce plaque . gingivitis and dental cariesCosmetic mouthwashes may be formulated to reduce bad breath through the use of antimicrobial and or flavoring agents Mouthwashes cont Mouthwashes are used as a dosage form for a number of. specific problems in the oraI cavity e g mouthwashes containingcombination of antihistamines hydrocortisone nystatin and tetracycline have been prepared for the treatment of stomatitis a painful side effect of cancer therapy.pilocarpine for xerostoma dry mouth tranexamic acid for the prevention of bleeding after oral carbenoxolone for the treatment of orofacial herpes simplex Emulsion (Liquid in Liquid dispersion): Emulsions are two phase system in which one liquid is dispersed through out another liquid in the form of small particles.. Colloids: A system in which finely divided particles, which are approximately less than 1 . Âµ. m in size, are dispersed within a continuous medium in a manner that prevents them from being filtered easily or settled rapidly.