Sep 29, 2017 In pediatric patients from birth through 16 years of age assessable for apnea who received bolus doses of propofol injectable emulsion (1 mg/kg to 3.6 mg/kg), apnea lasted less than 30 seconds in 12% of patients, 30 seconds to 60 seconds in 10% of patients, and more than 60 seconds in 5% of patients. Assumes monomolecular layers of emulsifying agent curved around a droplet of the internal phase of the emulsion. The molecules of surfactants at the interface btwn dispersed and cont. Macbooster 5 0 1 – maintains and optimizes your system. Phases form a wedge, the curvature of which determines the size of the dispersed phase. Based on the presumption that certain emul agents orient themselves about and within a liquid in a manner reflective of.
Formulationof emulsions
(hydrophile-Lipophile Balance);
•Surface-active agents are amphiphiles in which the molecule or ioncontains both hydrophilic and lipophilic portions.
•Griffen developed a scale based on the balance between these twoopposing tendencies. This so called HLB scale.
nThe more hydrophilicsurfactant have high HLB numbers (in excess of 10),
nsurfactants with HLBnumbers from 1 to 10 considered to be lipophilic.
•the type of emulsion is related to the balance between hydrophilicand lipophilic solution tendencies of the surface-active emulsifying agent.
•Surfactants with a proper balance in their hydrophilic andlipophilic affinities are effective emulsifying agents since they tend toconcentrate at the oil / water interface. •The relationship between HLBvalues and the application of the surface active agent is shown in the table
0 –3Antifoaming
7 –9Wetting agent
13 –15Detergent
•If the HLB of the oil phase is known andthe type of emulsion desired is known (o/w or w/o), the formulator chooses twoemulsifying agents, one with an HLB value above and the second with an HLBvalue below ,that required by the oil. These are blended to give a mixture ofthe correct HLB. The following formula, should serve as an example.
Liquidpetrolatum (HLB 10.5) 50 gm
Span 80(HLB 4.3)
Water,Q.S100 ml
•Calculation
RequiredHLB =10.5
10.7 parts •The required weight of tween =5*6.2/10.7=2.9 gm
Preparation
•Theoil soluble span is dissolved in oil and heated to 75 C,
•Thewater soluble tween is added to the aqueous phase, which is heated to 70 C.
•Mixthe oil phase with the aqueous phase and stirred until cool. •Formulation additives:
2-Preservatives
4-Colors and flavorings.
•Some oils are liable to degradation by oxidation and thereforeantioxidants may be added to the formulation. They should be preferentiallysoluble in the oily phase. Antioxidants used in oral emulsions which areodorless and tasteless include ascorbic acid, citric acid, sodiummetabisulphite and sodium sulphite.
•Antioxidant is commonly used at concentrations ranging from 0.001to 0.1%. 2-Preservatives:
•Emulsions contain water, which will support microbial growth.Microbes produce unpleasant odors, color changes and gases, pH change andbreakdown of the emulsion
•Microbial growth normally occurs in the aqueous phase of anemulsion, therefore it is important that a sufficient concentration ofpreservative is, present in the aqueous phase.
nMethylparahydroxybenzoatein 0.2% & Propyl parahydroxybezoate in 0.02%. ,They are suitable for bothexternal and internal use.
nBenzoic acid, which iseffective at a concentration of 0.1% at pH below 5.
nChlorocresol (0.1 %). 3-Humectants:
nTo reduce theevaporation of the water either from the packaged product when the closure isremoved or from the surface of the skin after application.
nE.g., Propylene glycol,glycerol and sorbitol at a concentration around 5%.
nColour is rarely neededin an emulsion, as most have an elegant white colour and thick texture.
nEmulsions for oral usewill usually contain some flavouring agent. Example of emulsionformulations
Code liver oil 30 ml
Cinnamon water to 100 ml
•Prepare 100 ml cod liver oil emulsion (o/w emulsion for internaluse)
nCod liver oil is a fixedoil that requires the addition of acacia gum as an o/w emulsifying agent
0 w G
30 ml 15ml 7.5 g
nTherefore 30 ml cod liver oil, 15 ml of cinnamon water and 7.5 gof acacia gum will be used to prepare the primary emulsion. Cinnamon water actsas a flavouring agent and vehicle. .chloroform is dense only slowly soluble andact as a preservative.
Formulationof emulsions
(hydrophile-Lipophile Balance);
•Surface-active agents are amphiphiles in which the molecule or ioncontains both hydrophilic and lipophilic portions.
•Griffen developed a scale based on the balance between these twoopposing tendencies. This so called HLB scale.
nThe more hydrophilicsurfactant have high HLB numbers (in excess of 10),
nsurfactants with HLBnumbers from 1 to 10 considered to be lipophilic.
•the type of emulsion is related to the balance between hydrophilicand lipophilic solution tendencies of the surface-active emulsifying agent.
•Surfactants with a proper balance in their hydrophilic andlipophilic affinities are effective emulsifying agents since they tend toconcentrate at the oil / water interface. •The relationship between HLBvalues and the application of the surface active agent is shown in the table
0 –3Antifoaming
7 –9Wetting agent
13 –15Detergent
•If the HLB of the oil phase is known andthe type of emulsion desired is known (o/w or w/o), the formulator chooses twoemulsifying agents, one with an HLB value above and the second with an HLBvalue below ,that required by the oil. These are blended to give a mixture ofthe correct HLB. The following formula, should serve as an example.
Liquidpetrolatum (HLB 10.5) 50 gm
Span 80(HLB 4.3)
Water,Q.S100 ml
•Calculation
RequiredHLB =10.5
10.7 parts •The required weight of tween =5*6.2/10.7=2.9 gm
Preparation
•Theoil soluble span is dissolved in oil and heated to 75 C,
•Thewater soluble tween is added to the aqueous phase, which is heated to 70 C.
•Mixthe oil phase with the aqueous phase and stirred until cool. •Formulation additives:
2-Preservatives
4-Colors and flavorings.
•Some oils are liable to degradation by oxidation and thereforeantioxidants may be added to the formulation. They should be preferentiallysoluble in the oily phase. Antioxidants used in oral emulsions which areodorless and tasteless include ascorbic acid, citric acid, sodiummetabisulphite and sodium sulphite.
•Antioxidant is commonly used at concentrations ranging from 0.001to 0.1%. 2-Preservatives:
•Emulsions contain water, which will support microbial growth.Microbes produce unpleasant odors, color changes and gases, pH change andbreakdown of the emulsion
•Microbial growth normally occurs in the aqueous phase of anemulsion, therefore it is important that a sufficient concentration ofpreservative is, present in the aqueous phase.
nMethylparahydroxybenzoatein 0.2% & Propyl parahydroxybezoate in 0.02%. ,They are suitable for bothexternal and internal use.
nBenzoic acid, which iseffective at a concentration of 0.1% at pH below 5.
nChlorocresol (0.1 %). 3-Humectants:
nTo reduce theevaporation of the water either from the packaged product when the closure isremoved or from the surface of the skin after application.
Emulsion 1 3 6 10
nE.g., Propylene glycol,glycerol and sorbitol at a concentration around 5%.
nColour is rarely neededin an emulsion, as most have an elegant white colour and thick texture.
nEmulsions for oral usewill usually contain some flavouring agent. Example of emulsionformulations
Code liver oil 30 ml
Cinnamon water to 100 ml
•Prepare 100 ml cod liver oil emulsion (o/w emulsion for internaluse)
Emulsion 1 3 64
nCod liver oil is a fixedoil that requires the addition of acacia gum as an o/w emulsifying agent
Emulsion 1 3 600
0 w G
30 ml 15ml 7.5 g
nTherefore 30 ml cod liver oil, 15 ml of cinnamon water and 7.5 gof acacia gum will be used to prepare the primary emulsion. Cinnamon water actsas a flavouring agent and vehicle. .chloroform is dense only slowly soluble andact as a preservative.