ft 26-29 english.pdf
TRANSCRIPT
SEMI-‐SOLID PREPARATONS FOR CUTANEOUS APPLICATION
Part 2 • Exercise 26: UNGUENTUM EMULSIFICANS AQUOSUM • Exercise 27: CREAM FOR DRY SKIN WITH UREA • Exercise 28: SULPHUR OINTMENT • Exercise 29: CALCULATING THE HLB VALUE OF THE EMULSIFIER
OR THE REQUIRED HLB VALUE OF THE EMULSION SYSTEM FOLLOWING INDIVIDUAL RECIPE
Exercise 26: UNGUENTUM EMULSIFICANS AQUOSUM Hydrophilic ointment with water
Hydrophilic ointment 30 parts Water 70 parts
Melt hydrophilic ointment in a water bath at approx. 70°C. Gradually add previously boiled and cooled water adding small amounts at a Yme and mix well. ConYnue mixing the cream unYl it has cooled down, making sure to replace the water which was evaporated.
UNGUENTUM EMULSIFICANS
Hydrophilic ointment
Cetyl and stearyl alcohol, emulsifying (type A) 30 parts Liquid paraffin 35 parts White petrolatum 35 parts
If the method applied does not yield a well spreadable ointment, you can replace liquid paraffin with white petrolatum as necessary up to 10%
Prepara3on procedure Melt the ingredients in a water bath and sYr unYl the mixture has cooled down.
Hydrophilic cream!
Water emulsifying ointment (Ph. Eur.)!
• INGREDIENTS: • min. 80% of cetostearol • min. 7% of sodium cetyl and stearyl sulphate
• complex emulsifier • a mixture of an W/O and O/W emulsifying agents • synergy, properYes of one prevail • forms a more coherent (firm) film on the interfacial area as each emulsifier separately
CETOSTEARYL ALCOHOL, EMULSIFYING (TYPE A) lat. Alcohol cetylicus et stearylicus emulsificans A
EMULSIFIER O/W
mixture of Na-‐cetylsulphate (min 40%) and Na-‐stearylsulphate
C16H33SO4Na C18H37SO4Na
DETERMINING THE TYPE OF AN EMULSION
• DROP DILUTION TEST • ELECTRICAL CONDUCTIVITY TEST • COBALT PAPER
CoCl2 x 2 H2O CoCl2 x 6 H2O
• STAINING TEST
H2O
Exercise 27: CREAM FOR DRY SKIN WITH UREA Cream base with cholesterol 35,0
Olive oil 20,0 Urea 5,0 Purified water 40,0 Prepare 1/5 of prescribed mass.
Dissolve the acYve ingredient in water in a beaker. Add cream base with cholesterol to the container first then olive oil and at the end water soluYon of urea. Mix with Unguator at 1700 rpm for 90 seconds. During last 20 seconds use higher rpm and hold the container at lowest posiYon to “self clean” the mixer.
CREAM BASE WITH CHOLESTEROL
Cholesterol 5,0 Lanolin 9,5 White petrolatum 85,5
Melt all the ingredient on water bath at approximately 60°C and mix unYl cooled.
• CHOLESTEROL • cyclic sterol • emulsifier W/O → increases the absorpYon of acYve ingredients in the skin
• it forms a lipid barrier of the skin (together with ceramids and faky acids) → prevents water loss
• UREA • works as a moisturizer (increases the hydraYon of the stratum corneum due to the binding of water in its own crystal structure)
• UNGUATOR • device, which allows mixing of the components in a closed system
• CONDITIONS: Yme & speed of rotaYng
Exercise 28: SULFUR OINTMENT USP XXV Sulphur ointment
Precipitated Sulphur 100 g Mineral Oil 100 g White Ointment 800 g
WHITE OINTMENT White wax 50 g White petrolatum 950 g
To make white ointment you need to melt white petrolatum in a suitable dish (round-‐bokomed dish) in a water bath, add white petrolatum and heat unYl the mixture has melted. Remove the dish from the bath and mix unYl the mixture has cooled down. Prepare white ointment first, and the ointment with sulphur second.
• hydrophobic ointment – suspension • acts as scabicide (precipitated sulphur) • homogenizaYon of the ointment made ��with a three-‐roll mill → more even distribuYon of the parYcles in the ointment
EXCIPIENTS • WHITE WAX (beewax, white; Cera Alba) • beeswax is obtained by melYng the honeycomb (bleaching) • waxes? • myricyl palmitate
SUB-‐CATEGORY: CREAMS CREAMS
• emulsion gels • mulYphase preparaYons (lipophilic and aqueous phase)
HYDROPHOBIC HYDROPHILIC
• ConYnuous phase: lipophilic • Inner phase: aqueous phase
• ConYnuous phase: aqueous phase • Inner phase: lipophilic
EMULSIFIERS W/O • wool alcohols • sorbitan esters • monoglycerids
EMULSIFIERS O/W • sodium or trolamine soaps • sulphated faky alcohols • polysorbates (TWEEN) • polyoxyl faky acid and faky alcohol
esters
Exercise 29: CALCULATING THE HLB VALUE HLB – hidrophile lipophile balance
mass of the hydrophilic part of the molecule HLB = -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ x 100 x 1/5
total mass of the molecule • relaYve proporYon of the lipo-‐ and hydrophilic part of the molecule of a surfactant
• HLB value: 0 – 20 • it applies only to non-‐ionogenic emulsifiers • we can calculate it
The required HLB value (for emulsifying of the oil phase)
• some components of the lipophilic phase of the cream require a specific HLB value – required HLB value
• if there are more lipophilic components, the required HLB value is the sum of all required HLB values for each component, mulYplied by its relaYve proporYon • the selecYon of the emulsifiers in the cream depends on the required HLB value – the emulsifiers can be combined
Calculate the required HLB value of the lipophilic phase of an O/W emulsion:
Liquid paraffin 35 Cera Alba 1 Cetyl alcohol 1 Emulsifiers 7 Glycerol 10 Purified Water 46
37
Required HLB value
lipophilic components proporYon of the component in the lipophilic
phase
fracYon
Liquid paraffin 12 x 35/37 Cera Alba 10 x 35/37 Cetyl alcohol 15 x 35/37
11,4 0,3 0,4
Required HLB value: 12,1
Required HLB value of the lipophilic phase in O/W emulsion is 12,1. How much of the each emulsifier Span 80 (HLB=4,3) and Tween 80 (HLB=15) is needed for the preparaYon of the cream?
4,3 ·∙ x + 15 ·∙ (1-‐x) = 12,1 x = 0,73
0,73 × 7 g = 5,1 g Span 80 7 g – 5,1 g = 1,9 g Tween 80
TWEEN® • type O/W • esters of sorbitan with faky acids and ethers of polyethylene glycols (polysorbates)
Tween 60 = polysorbat 60 = polyoxyethylene 20 sorbitan monostearat e R = C17H35 w + x + y + z = 20 HLB = (1045/1312) x 20 = 15,93
SPAN® • esters of sorbitan with faky acids • typ W/O emulsifier
Span 20 = sorbitan monolavrate → R = C11H23
BRIJ® • ethers of faky alcohols and PEG
R-CH2-O-CH2-(CH2-O-CH2)n-CH2-OH
Brij 30 = polyoxyethylen-‐4-‐lavryl ether → R=C11H23; 4 (CH2-‐O-‐CH2) units