Oral Solution Dosage Forms II (Methods) Flashcards
The perquisite for pharmaceutical solution is the exclusive presence of…
dissolved therapeutic agent
Which components of formulation (therapeutic agent + excipients) should be soluble?
ALL components - with NO evidence of precitipation
Pharmaceutical oral solutions=
Oral solutions
Oral syrups
Oral elixirs Linctus
Lactulose oral solution excipient?
Purified water (lactulose is water-soluble)
What is the use of laculose oral solution?
used as a laxative in the treatment of chronic constipation in adults and geriatric patients
What does lactulose consist of?
one molecule of GALACTOSE and one molecule of FRUCTOSE = a synthetic. disaccharide derivative of lactose
Is lactulose absorbed or unabsorbed?
UNabsorbed - produces an osmotic diarrhoea
Oral syrups properties?
HIGHLY concentrated, aqueous solutions of a sugar or a sugar substitute
- contains flavouring agents
- UNFLAVOURED syrup contains 85% sucrose
What are major components of oral syrups?
1) purified water
2)Sugar (sucrose) | sorbitol (non-sucrose) | sugar substitutes (artificial sweeteners)
Do syrups have high or low viscosity?
HIGH = due to inherent sweetness
High (sucrose) and associated unavailability of water (low water activity)…
- preservatives
Consideration to the physiochemical properties of the drug
Cherry syrup + orange syrup acidic»_space;> solubility of acidic drugs may be lowered
equation used:
pH − pKa = log([A^−])/([HA])
Reduced chemical stability for acid-labile therapeutic agents
Medicated sugar-free syrups due to
Glycogenetic and cariogenic properties of sucrose
For administration to children and to diabetic patients
Syrup substitutes must provide equivalent:
sweetness, viscosity and preservation to the original syrups
To achieve these properties (sweet, viscosity and preservation)…
Artificial sweeteners (typically saccharin sodium, aspartame)
Non-glycogenetic viscosity modifiers (e.g. methylcellulose, hydroxyethylcellulose)
Preservatives (e.g. sodium benzoate, benzoic acid and parahydroxybenzoate esters) are included.
Methyl parahydroxybenzoate
preservative
Xathan gum
↑ viscosity
Citric acid monohydrate
antioxidant; buffering agent
Raspberry aroma flavouring
synthetic and natural flavourings
What are oral ELIXIRS?
s a clear, hydroalcoholic solution for oral use
Why is alcohol required in oral solution of elixirs?
To ensure all components remain in solution
* Other polyol co-solvents may be
incorporated
why is adding alcohol a possible problem?
For adults who wish to avoid alcohol/alcoholics - quitting
Typical components of ELIXIRS:
- Purified water
- Alcohol
- co-solvent to ensure solubility
- Polyol co-solvents
- Propylene glycol, glycerol to enhance solubility
- Enables the [alcohol] to be reduced
- Sweetening agents
- Similar to syrups
- High [alcohol] prohibits the incorporation of high [sucrose] due to the limited solubility of this sweetening agent in the elixir vehicle
- Flavours and colours
Phenergan elixir contains…
promethazine (antihistamine)
Promethazine is used as…
- As symptomatic treatment for allergic conditions of the upper respiratory tract and skin including allergic rhinitis, urticaria and anaphylactic reactions to drugs and foreign proteins
- As an antiemetic
- For short term use
○ Treatment of insomnia in adults
○ Paediatric sedative
How is Phenergan elixir suitable and designed for children?
An alcohol-free, sugar-free antihistamine formulation designed for use by children
Maltitol liquid
sweetening agent
Citric acid monohydrate
antioxidant; buffering agent
Sodium citrate
buffering agent; chelating agent
Orange juice
flavour
Caramel
colourant
Sodium metabisulphite
preservative; antioxidant
Linctuses:
- Viscous preparations that contain the therapeutic agent dissolved in a vehicle composed of a high percentage of sucrose and, if required, other sweetening agents
Why is linctures used:
the treatment of relief of dry, irritating cough, due to their soothing actions on the inflamed mucous membranes
Can linctuses be sugar-free?
Yes, for patients with diabetes
Ethanol (96%)
co-solvent
Quinoline Yellow
colourant
Benzoic Acid Solution
preservative
Lemon Oil Terpeneless
flavour
Citric Acid Monohydrate
antioxidant; buffering agent
Mouthwashes and gargles are used for;
treatment of infection and inflammation of the oral cavity
Water as the vehicle
Co-solvent may be employed to solubilise the active agent
What is a vehicle?
A carrier or inert medium used as a solvent (or diluent) in which the medicinally active agent is formulated and or administered
What is the effect of alcohol on the mouthwashes/ garlgles?
may enhance the antimicrobial properties of the therapeutic agent
Methyl Salicylate
antiseptic
Thymol
antioxidative and anti-inflammatory
Zinc Chloride
reduce morning oral malodour
