Furthermore, the presence of USFA such as linoleic and linolenic acid lessening the runing point of oil and more prone to autoxidation McClements and Decker, Finally, the vegetable oil has unwanted off-flavour and off-odour that influence the shelf life and consumer acceptableness.
This makes it possible to provide a composition with improved or suitable tolerability to the end user. This is of particular use, when the amount of pharmaceutically active agent can be increased in the composition such that with each application of the composition to the eye, an increased level of pharmaceutically active agent is administered.
The ophthalmic compositions described herein also have an advantage of potentially allowing higher levels of pharmaceutically active agent into the compositions compared to known ophthalmic compositions.
This may be possible for example if the active is soluble or at least partially soluble in the discontinuous preferably oil phase of the polyaphron dispersion.
Polyaphron dispersion may have higher levels of oil and still remain stable compared to other compositions, for example though comprising emulsions.
This may be achieved by improved permeation. Advantageously the compositions are stable over an extended period of time, for example over 3 months, 6 months or 9 months or 12 to 24 months.
Preferably the ophthalmic composition as described herein has at least one or more of the following advantages over known ophthalmic compositions, which may, for example, assist in improving patient compliance: Moreover, the ophthalmic compositions described herein achieve the described benefits whilst having low levels of surfactants.
This is advantageous as surfactants may be irritants. In the following description, the meaning of the terms used are as follows: By hydrophobic phase or solvent is meant a phase comprising pharmaceutically acceptable liquids such as oils that are immiscible or substantially immiscible with the hydrophilic phase.
By immiscible liquids is meant that when mixed together, they separate to form two distinctly separate liquid phases sharing a well-defined interface.
By substantially immiscible is meant that two liquids mixed as above having a well defined interface between two phases where each phase may nevertheless contain small quantities of dissolved molecules of the other phase.
A polyaphron dispersion comprises a continuous phase, a discontinuous phase and a surfactant. It will be understood that typically a polyaphron dispersion comprises one continuous phase and a plurality of discontinuous phases.
The polyaphron dispersion may comprise a hydrophobic discontinuous phase, and a hydrophilic continuous phase.
Alternatively, the polyaphron dispersion may comprise a hydrophilic discontinuous phase and a hydrophobic continuous phase. By polyaphron dispersion as used herein is meant a particular kind of hydrophilic liquid-in-hydrophobic liquid or hydrophobic liquid-in-hydrophilic liquid dispersion comprising a a hydrophilic liquid miscible phase, b a second hydrophobic phase being immiscible or substantially immiscible with the first phase and c one or more surfactants, wherein the dispersed or discontinuous phase is in the form of small e.
Gel Polyaphron Dispersions as described in 2 above can be diluted to any extent by the addition of more continuous phase without the addition of more surfactant, when the gel-like properties disappear. Simple shaking of the diluted dispersion instantly causes a homogeneous, stable dispersion of Colloidal Liquid Aphrons to re-form.
Each of the above characteristics and a combination of them clearly differentiate the polyaphron dispersions of the present invention from conventional emulsions and other dispersion types which do not have all of those characteristics.
Polyaphron dispersions are disclosed in the following literature references by Sebba: In US 5, a composition comprising a polyaphron dispersion is described as "a viscoelastic gel".
All descriptions that refer to dispersions having the characteristics described above are polyaphron dispersions as used in the present invention. The term "topical composition" and "topical formulation" are used herein interchangeably.
When the topical composition comprises an active ingredient sit refers to a composition formulated such that the active ingredient s of the composition may be applied by direct administration to the surface of the eye and from which an amount of the active ingredient s is released.
Examples of topical formulations include, but are not limited to, lotions, sprays, hydrogels, aerosols, foams, ointments, creams, gels, pastes, and the like.
The term "topical", when used herein to characterize the delivery, administration or application of a composition of the present invention, is meant to specify that the composition is delivered, administered or applied directly to the site of interest i.
Preferably, topical administration is effected without any significant absorption of components of the composition into the subject's blood stream to avoid a systemic effect. In certain preferred embodiments of the present invention, topical administration of a composition is effected without any significant absorption of components of the composition into the subject's eye tissues, such as the aqueous humor, and corneal and conjunctival tissues.
The term "non-invasive", when used herein refers to a method or mode of administration that does not rupture or puncture e. Preferably, the ophthalmic composition as described herein is administered by non-invasive routes or procedures.
The term "ophthalmic", as used herein in connection with a composition, refers to a composition intended to be administered to the eye and which preferably provides a pharmaceutical effect, preferably to the eye.
The terms "therapeutic agent", "drug", and "pharmaceutically active agent" are used herein interchangeably. They refer to a substance, molecule, compound, agent, factor or composition effective in the treatment of a disease or condition. In one embodiment the ophthalmic composition as described herein is not for use in tear replacement therapy, nor for use as a tear substitute, nor is it for use in a tear replacement solution.
In one embodiment, the ophthalmic - De composition as described herein is for use in treating diseases of the eye with the proviso that it is not for use in treating "dry-eye". As described above, a polyaphron dispersion comprises a continuous phase, at least one discontinuous phase and a surfactant.
The polyaphron dispersion may comprise a hydrophobic discontinuous phase typically a plurality of hydrophobic discontinuous phasesand a hydrophilic continuous phase. Alternatively, the polyaphron dispersion may comprise a hydrophilic discontinuous phase typically a plurality of hydrophilic discontinuous phasesand a hydrophobic continuous phase.
Preferably, the discontinuous phase comprises a hydrophobic solvent and the continuous phase comprises a hydrophilic solvent. Preferably the discontinuous phase is a hydrophobic discontinuous phase comprising one or more hydrophobic solvents and substantially no hydrophilic solvents.
Preferably the continuous phase is a hydrophilic continuous phase comprising one or more hydrophilic solvents and substantially no hydrophobic solvents. Typically a plurality of discontinuous phases are present in the composition.a) Write an equation for the hydrogenation of glyceryl trilinolenate, a fat formed from glycerol and three linolenic acid molecules.
b) Write an equation for the acid hydrolysis of /5(K). What is the chemical equation for the hydrolysis of a lipid? The most common members of the 'lipid family' are triglycerides:plant oil and fats, being 3-fold esters of three molecules ofalkanoic (or alk-ene-oic) acids with one molecule of glycerol(1,2,3-propan-tri-ol).
4) (3 pts)Write an equation for each of the following reactions: a) Esterification of glycerol with three molecules of myristic acid b) Base (NaOH) hydrolysis or saponification of glyceryl tristearate c) Reaction of decanoic acid with KOH d) Hydrogenation of linoleic acid.
An ester is a product of the reaction of an acid (usually organic) and an alcohol (the hydrogen of the acid R-COOH is replaced by an alkyl group R'). Esters mainly result from the condensation (a reaction that produces water) of a carboxylic acid and an alcohol. Write an equation for the hydrogenation of glyceryl trilinolenate, a fat containing glycerol and three linolenic acid units.
4. Write the equation for the acid hydrolysis of glyceryl trioleate (triolein). Tone-neutralizing eye base that helps set eyeshadow.
The creamy texture aids both the application and setting of the eyeshadow, extending its hold over time*. Its light pigmentation neutralizes the colour of your eyelids, emphasizing the eyeshadow’s colour.
The finish is delicate and natural for.