Liquid Dosage Forms Flashcards
Give examples of cosolvents / water-miscible solvents and the example on using them
ethanol
propylene glycol
glycerin
sorbitol
Used in elixirs
Give examples of complex actions
- Iodine with KI2
- Iodine with PVP —> ex: 10% betadine
- Poorly sol drugs with beta-cyclodextrin
What are hydrotropic agents or salts used ?
- Sodium acetate —> ⬆️ sol of theophylline
- Sodium benzoate —> 30% —> ⬆️ sol caffeine/ benzoic acid / cholesterol
- Sodium salicylate —> ⬆️ sol of salicylic acid
- Sodium glycinate —> ⬆️ sol of theophylline
How to ⬆️ the solubilizing power of a surfactant ?
Electrolytes can increase the solubilizing power of surfactants by:
- reducing their cmc
- increasing the size of the resultant micelles.
What is the problem with using surfactants ?
a preservative may preferentially partitions into micelles
—> effective conc. is reduced.
Give examples on using surfactants
- Potassium oleate e.g. Cresol
Solubilize antiseptic substances
- Tween 80 e.g. kiddo pharmaton syrup
Solubilize oil soluble vitamins to allow adding water soluble vitamins
How to apply chemical modifications to increase sol?
- Formation of water-soluble derivatives —> by increasing the number of polar groups in a molecule by salt formation for example (e.g. chlorpromazine HCl)
- molecule may be modified to produce a new chemical entity or prodrug. (Prodrugs must revert to the parent molecule after administration) (e.g. Chloramphenicol sodium succinate)
When to use nonAq solutions?
- Diff to make comp aq solution of the ingredients at all storage temps
- Drug unstable in aq systems
- Depot therapy req e.g. IM injection of testosterone propionate oily solution.
What are the non Aq vehicles ?
- Fixed veg oils
- Monohydric alcohols
- Polyhydric alcohols
- Ethyl ether
What are the fixed vegetable oils used as nonAq solutions?
maize oil (corn oil)
Olive oil
cottonseed oil —> in vit A oral prep
castor oil —> in Triamcinolone ear drops
arachis (peanut) oil —> in Methyl salicylate liniment
sesame oil —> in testosterone enanthate inj. (Deltatestryl)
ethyl oleate ester —> testosterone propionate injection
MOC CASE
What are the monohydric alcohols? Have 1 OH
- Ethanol
• external application on unbroken skin.
• Its rapid evaporation after application imparts a cooling effect to the skin. e.g., salicylic acid lotion.
• Ethanol usually denatured (contains 5% methanol as a
denaturant, e.g., Industrial Methylated Spirit, IMS), which
is too toxic for internal use - Isopropyl alcohol
• It has similar properties as ethanol and used externally.
• Main advantage: - it is less likely to be abused than ethanol
- denaturation is not necessary.
What are the polyhydric alcohols ? ( 2 OH or more —> glycols )
- Propylene Glycol
A. Oral
B. Ear
C. Parenteral - Polyethylene Glycols (PEG)
Rarely used internally
Used: externally and parenterally
C. Glycerol
D. Sorbitol —> sweetening agent
E. Mannitol
What is ethyl ether ?
Used externally when mixed with alcohol 3:1 (v/v) —> to dissolve pyroxylin (a nitrocellulose product) in the preparation of collodions.
What are the flavoring and sweetening agents types?
A. SWEETENING AGENTS B. FLAVOURED SYRUPS C. AROMATIC OILS D. SYNTHETIC AROMATIC SUBSTANCES E. JUICES F. TINCTURES G. EXTRACTS
Give examples of sweeting agents
- Sucrose —> simple syrup BP
- Invert sugar —> invert syrup BP
- Sorbitol —> sorbitol solution 70% BP
- Saccharin sodium ( 10% solution )
Why sucrose is replaced by sorbitol ( 60% sweeter )?
- Avoid the risk of dental caries
2. For diabetic patients
Why do we add 10% of invert sugar ( 70% sweeter ) to syrups?
to retard crystallisation of sucrose, e.g. Lemon Syrup.
Why are the polyhydric glycols sweetening?
Bcz they are converted in the liver into glucose. They are not absorbed well from the GIT.
Why do we add polyhydric glycol to syrups?
نفس سبب الinvert sugar بس زيادة سبب
- retard crystallisation of sucrose
2. increase solubility of other ingredients.
What is the diff btwn saccharin and saccharin sodium ( 400 - 700 times sweeter than sucrose )
Unlike saccharin, saccharin sodium does not leave a
bitter after-taste.
What are the examples of fruit flavored syrups?
Lemon Syrup BP
Orange Syrup BP: prepared from Orange Tincture BP.
Raspberry Syrup BP
What is the benefit of cocoa syrup?
masking bitter drugs in pediatric products.
What is orange tincture? (She said imp)
- Has bitter taste
- Stimulate appetite —> to encourage food intake
- Useful in preps with Fe or vitamins
Ex:
- Paediatric Ferrous Sulphate Mixture
- Vitamin B complex syrup.
What are the aromatic oils ?
Volatile oils prepared as: 1. Aromatic waters A. Anise Water BP B. Dill Water C. Ginger Water D. Peppermint Water
- Spirits ( alcoholic or hydro alcoholic sols of volatile subs )
A. Lemon Spirit
B. Peppermint Spirit
C. Compound Orange Spirit
What are the characteristics of aromatic waters?
- mild carminative action
- relieves flatulence and has been used in antacid mixtures for adults —> peppermint
- mild expectorant; useful in cough mixtures —> anise
What are synthetic aromatic subs
- Chloroform ex:
A. Chloroform Water BP - Double Strength Chloroform Water BP
- Chloroform Spirit BP
- Vanillin —> oral emulsion
- Benzaldehyde —> has the odor of bitter almond —> oral emulsion
What is special about chloroform?
- Flavoring
- Sweetening
- Antimicrobial
- Preservative
- Vehicle
What are the juices used as flavoring and sweetening agents ?
Juices are aqueous liquids obtained from fruits and other plant parts.
Ex: Concentrated Raspberry Juice BP.
What is pectinase?
- added to the juice to destroy the pectin
2. the juice is then clarified by filtration
What is the diff btwn infusions and conc infusions?
- diluted solutions (1:10) containing the readily-soluble constituents of crude medicinal plants
- Concentrated infusions are 25% ethanol cold extracts of crude medicinal plants
What are the subs that are bitter as stimulate appetite?
- Orange tincture
- Orange Peel Infusion BP
- Compound Gentian Infusion BP
1 syrup 2 infusions
What are the tinctures?
hydroalcoholic solutions (15-80%) prepared from medicinal substances (including herbs).
What is the diff btwn extracts and tinctures?
Tinctures are weaker (lower concentration) than extracts.
What is the use of orange tincture BP **?
Tincture: prepared by extracting the dried bitter-orange peel powder with 70% ethanol
Syrup
Bitter
Stimulate appetite
What are the flavoring and sweetening agents that are mild expectorants?
- Ipecacuanha Tincture BP
- Squill Tincture BP
- Senega Tincture BP
- Liquorice Liquid Extract BP.
What are the extracts ?
- Obtained by extracting medicinal plants with suitable
solvents. - contain the active principles of the medicinal plants
- concentrated to form liquid, soft or dry extract.
Ex: Liquorice Liquid Extract BP.
A. Sweet flavoring
B. Mask bitter taste
C. Mild expectorant
What are the coloring agents?
- must have psychogenic balance with the taste and the odour.
يعني لو طعمه فراولة ميكنة لونه برتقالي
What are the types of coloring agents?
1. Natural colors l Carotenoids (yellow) l Chlorophylls (green) l Caramel (burnt sugar) l Saffron l Cochineal (a dried insect, red colour)
2. Coal tar dyes: sodium salts of sulphonic acids, obtained from coal tar. l Amaranth (red) l Carmoisine (red) l Green S, l Orange G l Patent blue l Tartrazine (orange-yellow)
Coal radar dyes give brighter colours and are more stable than natural
materials.
What is comp tartrazine solution BPC?
Tartrazine + orange G = saffron yellow
Why we use coloring agents ?
- Associated with flavours.
- To improve the attractiveness of the product.
- For easy identification of products particularly of poisonous materials (e.g., IMS) or to differentiate between antiseptic solutions used in hospitals (for skin, instruments, floor etc.)
- To mask the harmless coloured degradation product.
