Structure and Uses of Ibuprofen

structure and Uses of isobutylphenyl propionic acidAbstractThe Controlled- ext close window pane causes argon formulated to unc everyplace the medicines mobile voice ingredient gradually and predictably over an extended period of magazine that is something like 12 to 24 hour period. These formulations potencely provide for great effectiveness in the treatment of chronic conditions by much lucid deli really of the medication reduced side effects greater t oilet facility and advanceder levels of patient compliance due to a simplified dosage schedule, compargond with those of immediate- electric arc medicines.ibuprofen is a colourless, lucid solid which is having a low alcohol-soluble limits in body of water still it is having a better solublity in roughly organic resultant roles. The main aim of this work up is control the introduce of medicine by encapsulating it in to cove resound veridicals like fatty blisterings (palmitic tart and pluronic F-127). Encapsul ating of ibuprofen by employ freeze drying technique in this technique iso howe actuallylphenyl propionic acid is encapsulated in to the fattyacid and pluronic (F127), these coating materials bring on the property of controlling the grow of medicate when the coated do demigods is entered in to the be the coating materials which surrounded to the drug is control the release of drug. The release of encapsulated ibuprofen is determined by give ear through dis resultant role and UV- discernible spectroscopy.INTRODUCTION1. IBUPROFEN iso preciselyylphenyl propionic acid is a colourless, crystalline solid which is having a precise very low solubility limits I topic of water exclusively it is having comparabelly better soluble limits in case of organic resolvents. The synthesis of ibuprofen was originally reported in 1964 from -isobutyl- lacetophen but the drug was non marketed in the United States until 1974 despite the fact that it had been on hand(predicate) for several (prenominal) years in Europe. It was the indomethacin and was immediately accepted in therapy. Its success was a factor in the introduction of m any(prenominal) spick-and-span agents in the 1970s. ibuprofen was the first aryl propionic acid derivative to be marketed in the United States. This chemical class currently comprises of the largest group of NSAIDs at a lower place probe with as many as 25 derivatives in various stages of development. It recently became the first prescription NSAIA to become available as an over the proceeds analgesic in al closely 30 years and is avialble under(a) a number of trade elevates, It is also sometimes know as Advil, Anadin Ibuprofen, Arthrofen, Brufen, Retard, Cuprofen, Fenbid Galprofen, Hedex Ibuprofen, Ibufem Librofem Mandafen Manorfen Migrafen ibuprofen Nurofen Obifen Relcofen perhaps being among the much widely utilise. The continuing popularity of ibuprofen is prove by the appearance 200 prescription drugs in the United States.IU PAC name 2-4-(2-methylpropyl) phenyl propanoacid,Formula C13H18O2, molecular mass 206.28,Melting organise 76 C (1. 69 F)Bioavail talent 49-73,Protein binding 99%, metamorphosis Hepatic,Half life 1.8-2 hours, riddance Renal.1.1 Structure of IbuprofenStructure of IBUPROFENIbuprofen is a snowy powder belonging to the propionic acid derivatives, with a melting point of 74 77 C. It is only s uninfectedly soluble in water but readily soluble in organic solvents untold(prenominal) as ethanol. It is a chiral compound racemic Ibuprofen is usually utilize, although only one form is fighting(a) medicinally.Ibuprofen is made up of covalently-bonded carbon, hydrogen, and oxygen atoms. 2 CH3 molecules be single-bonded to a CH molecule The CH molecule is bonded to a carbon atom that forms a 6-sided ring of carbon atoms. An different CH molecule is single-bonded to a carbon atom on the other side of the ring. Inside the ring there are 3 double bonds between carbon atoms. Then a nonher CH3 molecule and a COOH molecule are two single bonded to the CH molecule on the right. Because it is nonsteroidal, it is widely apply as it does not unhappy the hormonalbalance in the body. Its anti-inflammatory, analgesic (pain relieving) and antipyretic (fever reducing) actions are co mode tempo pain much(prenominal)(prenominal) as liberty chitache, toothache, and migraine as well as symptoms of fever.1.2 StereochemistryIbuprofen contains a chiral carbon in the position of the propionate moiety. As such, there are 2 possible enantiomers of ibuprofen, with the potential for diametric biological effects and metabolism for sepa arrayly enantiomer. Indeed it was order that (S)(+)- ibuprofen (dexibuprofen) was the active form both in vitro and in vivo, because of this reason the ibuprofen is marketed as a single enantiomer as occurs with naproxen and other NSAIDs.And the in vivo experiments revealed the existence of an Isomerase (2-arylpropionylco-A epimerase) whic h converted (R) -ibuprofen to the active (S)-enantiomer .Most of the ibuprofen formulations are marketed as racemic mixtures. Racemic ibuprofen is an important NSAID used in the treatment of pain and inflammation in a admixture of musculoskeletal rheumatic disorders.1.3 Synthesis in that location have been many commercialised and laboratory publications for the synthesis of Ibuprofen. Two of the al approximately popular ways to pay off Ibuprofen are the Boot process and the Hoechst process. The Boot process is an old(a) commercial process developed by the Boot Pure medicate Company, and the Hoechst process is a newer process developed by the Hoechst Company. Most of these routes to Ibuprofen begin with isobutyl benzene and use Friedel-Crafts acylation. The Boot process requires six steps, enchantment the Hoechst process, with the assistance of catalysts, is completed in only three steps.Cheminor Drugs have developed a process for an improved version of ibuprofen found on chi ral synthesis. The move is signifi senst given that pure S-Ibuprofen (the active form of ibuprofen) could near halve the regular ibuprofen dosage, besides improving the side-effect profile. just the human body offer convert the inactive (R) form into the (S) form, so eventually 100% of the ibuprofen taken becomes active. The process discovered by Cheminor is therefore unlikely to have commercial signifi back toothce. 61.4 Mechanism of actionIbuprofen is an NSAID which is believed to work through suppression of cyclooxygenase (COX), then inhibiting prostaglandin synthesis. in that respect are at least 2 variants of cyclooxygenase (COX-1 and COX-2). Ibuprofen inhibits both COX-1 and COX-2. It appears that its analgesic, antipyretic, and anti-inflammatory activity is achieved principally through COX-2 forbidding whereas COX-1 inhibition is responsible for its unwanted effects on blood platelet aggregation and the GI mucosa. The role of the individual COX isoforms in the analgesi c, anti-inflammatory, and stomachal damage effects of NSAIDs is un authorized and different compounds cause different degrees of analgesia and gastric damage.1.5 Absorption and metabolismIbuprofen is quite rapidly preoccupied when it is admistered unwrittenly we fucking witness the diadem plasma levels are obtained withan 2hours time. As with most of these acidic NSAIDs , ibuprofen(pka=4.43) is extensively bound to the plasma proteins(99%) and will interact with other acidic drugs which are protein bound. Metabolism occur rapidly and the drug is nearly completely excreted in the urine as UN changed drug and oxidative metabolites with in 24 hrs following administration. Metabolism involves primarily -1and -2 oxidisation of the -iso butyl side chain, followed by alcohol oxidation of the primary alcohol resulting from the -oxidation to the alike carboxylic acid. exclusively metabolites are essentially in active. When Ibuprofen id administered as the individual enantiomers, the m ajor metabolites uncaring are the (+)-isomers regardless of the configuration of the administered enantiomer.intrestingley, the (R)(-)-enantiomer is anatropous to the (S)-(+)-enantiomer in vivo, accounting for the observation that the two enantiomers are bioequivalent In vivo.1.6 Ibuprofen usesIbuprofen is used to relief the symptoms of a wide range of illnesses such as headaches, pratache, period pain, dental pain, neuralgia, rheumatic pain, muscular pain, migraine, cold and influenza symptoms and arthritis.Recently evidence has emerged suggesting that ibuprofen is effective in the treatment of Alzheimers disease.1.7 Ibuprofen side effectsIbuprofen is regarded as the first choice drug in its class due to the low number of side effects and complications associated with it.The most frequent type of adverse reaction occurring with ibuprofen is GI. In clinical trials, the percentage of patients reporting one or more gastrointestinal complaints ranged from 4% to 16%.Common Side Effe cts stomach upset or irritationInfrequent Side Effects nausea and/or vomiting, constipation, diarrhoeaRare Side Effects skin irritations, drowsiness, gastrointestinal exhaustIbuprofen has the terminal incidence of gastrointestinal adverse effects, reactions of all the non selective NSAIDS. However this only holds true in case of lower doses of ibuprofen, so over the counter preparation of ibuprofen are generally designate to advise a maximum daily dose of 1,200 mg.1.8 Risks involved1.8.1 cardiovascular RiskAlong with several other NSAIDs, ibuprofen has been implicated in elevating the risk of myocardial infarction, particularly among those chronically using mellow doses.1.8.2 Risks in PregnancyIbuprofen pulmonary tuberculosis should be avoided in late maternity due to risk of premature closure of the ducts arteries in the fetal heart.1.8.3 Risks in Inflammatory Bowel DiseaseIbuprofen should not be used regularly in individuals with Inflammatory Bowel Diseas (IBD-Crohns Disease and Ulcerative Colitis)due to its ability to cause gastric bleeding and form ulceration in the gastric lining. Drugs such as Advil should be avoided in persons afflicted with IBD. disoblige relievers such as Tylenol (containing acet aminicphen) or drugs containing Codeine (which slows down bowel activity) are safer rules than Ibuprofen for pain relief in IBD. Ibuprofen is also known to cause worsening of IBD during times of a flare-up, thus should be avoided completely.1.8.4Drug-Drug InteractionsIbuprofen is associated with several suspected or other probable interactions that can feign the action of other drugs .Ibuprofen forgets to the increased levels of atomic number 3 leading to the reduction of lithium excretion from the kidneys, and this whitethorn lead to lithium toxicity. Ibuprofen may lead to the lowering of blood pressure because prostaglandins play an important role in reducing the blood pressure. Ibuprofen is used in combination with amino glycosides fore.g. The bl ood levels of gentamycin may increase presumably because the elimination of amino glycosides from the body is reduced and may lead to amino glycoside side effect.1.9. Absorption and MetabolismIbuprofen is rapidly absor chicane on oral administration with peak plasma levels being generally attained with in 2hrs. As with most of these acidic NSAIDs , ibuprofen(pka=4.43) is extensively bound to the plasma proteins(99%) and will interact with other acidic drugs which are protein bound. Metabolism involves primarily -1and -2 oxidation of the -iso butyl side chain, followed by alcohol oxidation of the primary alcohol resulting from the -oxidation to the corresponding carboxylic acid. tout ensemble the metabolites are essentially inactive. The (R)(-)-enantiomer is inverted to the (S)-(+)-enantiomer in vivo, accounting for the observation that the two enantiomers are bioequivalent In vivo.1.9 Mechanism of ActionIbuprofen is an NSAID which is believed to work through inhibition of cyclooxyg enase (COX), thus inhibiting prostaglandin synthesis. Prostaglandins are getd in receipt to injury or certain diseases 2 variants of cyclooxygenase (COX-1 and COX-2). Ibuprofen inhibits both COX-1 and COX-2. It appears that its analgesic, antipyretic, and anti-inflammatory activity is achieved principally through COX-2 inhibition whereas COX-1 inhibition is responsible for its unwanted effects on platelet aggregation and the GI mucosa. The role of the individual COX Isoforms in the Analgesic, Antiinflammatory, and the stomachic damage and affects of NSAIDs is uncertain and different degrees of Analgesia and Gastric damage occur.1.10 Controlled Release MechanismsControlled release implies regulation of the delivery of a a drug by a maneuver the control is aimed at delivering the drug at a particularized rate for a definite period of time independent of the local anaesthetic environments. Controlled release may also incorporate methods of promote localization of drug at an activ e site. Site specific and targeted delivery systems are the descriptive term used to denote this type of control. The periods of delivery are much longer than in case of sustained release and may set forth from days to years. Controlled release tool is designed to release the drug in vivo according to predictable pass judgment that can be verified by in-vitro measurements.Controlled release technology implies a quantities understanding of the physic chemical mechanism of drug availability to the extent that the dosage form release rate can be specified. Potential development s and new approaches to oral controlled release drug delivery systems, intragastric floating tablets, Trans mucosal tablets and little porous membrane coated tablets . An example of application to the controlled release technology to dosage form design consists of a polymer matrix in which a drug containing solution is dispersed in the form of micro booths. The barrier permeability and the drug solubility in the dispersed solution are variables that can be adjusted to provide predictable drug release rates. All pharmaceutical dosage forms should be controlled release formulations -with rate specified and bioavailability sensible by the drug delivery design.There are three types of controlled release mechanisms Diffusion Swelling Degradation2 .Palmitic acidPalmitic acid,CH3(CH2)14COOH or hexadecanoic acid in IUPAC nomenclature, is one of the most common saturated fatty acids found in animals and plants. As its name indicates, it is a major component of the oil from palm trees (palm oil and palm kernel oil). Palmitate is a term for the salts or esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiological pH.CAS number57-10-3 Molecular formulaC16H32O2Molar mass256.42 g/molAppearance sportsmanlike crystalsDensity0.853 g/cm3 at 62 CMelting point63-64 CBoiling point351-352 C2 215 C at 15 mmHg solubility in waterInsoluble2.1 BiochemistryPalmitic acid is the first fatty acid produced during lipogenesis (fatty acid synthesis) and from which longer fatty acids can be produced. Palmitate negatively feeds back on acetyl- CoA carboxyl(ACC) which is responsible for converting acetyl-CoA to malonyl-CoA which is used to add to the growing acyl chain, thus preventing further palmitate generation. Reduction of palmitic acid yields cetyl alcohol.2.2 UsesDerivatives of palmitic acid were used in combination with naphtha during knowledge base War II to produce napalm (aluminum naphthenate and aluminum palmitate). 6The World Health Organization claims there is convincing evidence that dietary ambition of palmitic acid increases risk of developing cardiovascular diseases. However, possibly less-disinterested studies have shown no ill effect, or even a favorable effect, of dietary consumption of palmitic acid on blood lipids and cardiovascular disease, so that the WHO finding may be deemed controversial.8 However, another study showed that pal mitic acid has no hypercholesterolaemic effect if intake of linoleic acid is greater than 4.5% of energy.On the other hand, it was shown that, if the diet contains trans fatty acids, the wellness effects are negative, causing an LDL cholesterol increase and alpha-lipoprotein cholesterol decrease. Recently, a long-acting anti-psychotic medication, paliperidone palmitate (marketed as INVEGA Sustenna), used in the treatment of schizophrenia, has been synthe coatd using the oily palmitate ester as a long-acting release carrier intermediate when injected intramuscularly.The underlying method of drug delivery is homogeneous to that used with decanoic acid to deliver long-acting depot medication, in particular, neuroleptics such as haloperidol decanoate.3 .Pluronic F-127Pluronic F127 is a difunctional block copolymer wetter terminating in primary hydroxyl groups. A non-ionic surfactant that is 100% active and relatively nontoxic.3.1 Specifications debauch point (10% aqueous).. 100CC olor, APHA 120 max.Water, weight %. Cast Solid-0.4 max.Prill/Micropastille-0.75 max.pH (2.5% aqueous) 6.0 7.03.2 Typical physical propertiesForm.. Cast solid /Prill /MicropastilleAverage molecular weight. 12600Specific gravity, 77/25C.. 1.05Viscosity, cps at 77C .. 3100Melt Point. 56CCloud point (1% aqueous). 100C Foam height (Ross Miles, 0.1%aqueous at 50C).. 40 mmSurface tension (0.1% aqueous).. 41 dynes/cm at25CHLB 18 23Solubility in water at 25C. 10%Wetting, Draves Sink Time(3-gm hook, 0.1% aqueous at 25C).. 360 secondsPluronicf-127 is polymer with an surplus property in aqueous solution which will covert from its lucid state to that of a non fluid hydrogel, which is a main characteristic of the protein drug delivery system.Pluronic-f127 is also considered as an Thermo Reversible Gelatine of the co-polymer f127 whose generic name is 407 in water calls it an unique panorama for Microencapsulaton application Pluronic-f127 is a surfactant molecule with highly beneficial char acteristics that makes it a strong candidate for protein drug delivery system. Its interaction with the polypeptides is most likely of minimisation of potential energy by mutual exclusion of hydrophobic residues from the aqueous medium as was predicted by computer probing and verified by empty-headed probing.4. MicroencapsulationThis is a process by which very tiny droplets or particles of unruffled or solid material are surrounded or coated with a continuous film of polymeric material. These micro-capsules have a number of benefits such as converting liquids to solids, separating reactive compounds, providing environmental protection, improved material handling properties. Active materials are then encapsulated in micron-sized capsules of barrier polymers (gelatin, plastic, wax, ).The reasons for micro encapsulation are countless. In some cases, the core essential be isolated from its surroundings, as in isolating vitamins from the deteriorating effects of oxygen, retarding va pour of a volatilizable core, improving the handling properties of a sticky material, or isolating a reactive core from chemical attack. In other cases, the objective is not to isolate the core completely but to control the rate at which it leaves the microcapsule, as in the controlled release of drugs or pesticides. The problem may be as simple as masking the taste or feel of the core, or as complex as increasing the selectivity of an adsorption or extraction.4.1 Micro encapsulation techniques*Physical methods of encapsulation Rotary disk atomization Fluid bed coating Stationary nozzle co extrusion Centrifugal head co extrusion Submerged nozzle co extrusion scatter drying Pan coating* Chemical methods of encapsulation Phase separation Solvent evaporation Solvent extraction Interfacial polymerization Simple and complex coacervation unmoved(p) polymerization Liposome technology* Shell materials used for en capsulation Proteins Polysaccharides Starches waxes Fats Natural and arti ficial polymers Resins4.2 Chemicals used in this experimentDrug IBUPROFENCoating polymer pvp and pluronic (f77)phosphate buffer (7.4)Composition of phosphate buffer kilobyte chloride Sodium chloride Potassium di hydro ortho phosphate Sodium di hydro ortho phosphate6. stay DryingFreeze-drying (also known as lyophilisation or cry desiccation) is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport. Freeze-drying works by halt the material and then reducing the surrounding pressure and adding enough light up to allow the frozen water in the material to sublime immediately from the solid phase to gas.There are several stages involved in the freeze drying process6.1 Freezing stage The freezing process consists of freezing the material. In a lab, this is often done by placing the material in a freeze-drying flask and rotating the flask in a bath, called a shell freezer, which is cooled by mechanical refrigeration, dry ice and methanol, or liquid nitrogen. On a larger-scale, freezing is usually done using a freeze-drying machine. In this step, it is important to cool the material below its eutectic point, the lowest temperature at which the solid and liquid phases of the material can coexist. This ensures that sublimation quite than melting will occur in the following steps. Larger crystals are easier to freeze-dry. To produce larger crystals, the product should be frozen slowly or can be cycled up and down in temperature. This cycling process is called annealing. However, in the case of food, or objects with formerly-living cubicles, large ice crystals will break the carrellphone walls (discovered byClarence Birdseye). Usually, the freezing temperatures are between -50 C and -80 C. The freezing phase is the most critical in the whole freeze-drying process, because the product can be spoiled if badly done. Amorphous (glassy) materials do not have an eutectic point, but do have a critical p oint, below which the product must be maintained to prevent melt-back or collapse during primary and standby drying.6.2 Primary drying Primary drying can reduce the moisture content of a freeze dried solid to around 0.5%. Further reduction can be effected by secondary drying. During the primary drying, the latent mania of sublimation must be provided and the vapour removed. enough heat is supplied to the material for the water to sublimate In this initial drying phase, about 95% of the water in the material is sublimated. This phase may be slow (can be several days in the industry), because, if too much heat is added, the materials structure could be altered.6.3 Secondary dryingThe removal of residual moisture at the end o primary drying is performed by raising the temperature of the solid to as high as 50C or 60C. A high temperature is permissible for many materials because the small amount of moisture remaining is not sufficient to cause spoilage6.4 Freeze drying advantagesDryin g takes place at very low temperatures, so that enzyme action is inhibited and chemical decomposition, particularly hydrolysis, is minimised.The solution is frozen such that the final dry product is a internet work of solid occupying the same volume as the original solution. hence the product is light and porous.The porous form of the product gives ready solubility.There is no ducking of the solution prior to drying. Hence, salts do not change state and denature proteins, as occurs with other drying methods.As the process takes place under high vacuum there is little contact with air, and oxidation is minimized.6.5 Freeze drying disadvantagesThe porosity, ready solubility and complete dryness yield a very hygroscopic product. Unless products are dried in their final container and sealed in situ, packaging requires special conditions.The process is very slow and uses complicated plant, which is very expensive. It is not a general method of drying, therefore, but is limited to cer tain types of valuable products which, because of their heat sensitivity, cannot be dried by any other means.7 Apparatus used for the experiment 7.1 Uv_visible spectroscopy A draw of the components of a typical spectrometer is shown in the following diagram. The functioning of this instrumental role is relatively straightforward. A publicize of light from a visible and/or UV light source (colored red) is separated into its component wavelengths by a prism or diffraction grating. Each monochromatic (single wavelength) beam in uprise is split into two equal extravagance beams by a half-mirrored device. One beam, the sample beam (colored magenta), passes through a small vapourish container (cuvette) containing a solution of the compound being studied in a transparent solvent. The other beam, the computer address (colored blue), passes through an identical cuvette containing only the solvent. The intensities of these light beams are then measured by electronic detectors and compa red. The intensity of the reference beam, which should have suffered little or no light absorption, is defined as I0. The intensity ofthe sample beam is defined as I. Over a short period of time, the spectrometer automatically scans all the component wavelengths in the manner described. The ultraviolet (UV) region scanned is normally from 200 to 400 nm, and the visible portion is from 400 to 800 nm. 11Components of UV_ visible spectroscopy7.2 InstrumentationSource of lightThe best source of light that which is more stable more wild and which gives range of spectrum from 180-360nm.The different sources available areHydrogen discharge lampIt is more stable robust and widely used.It gives radiation from 120-350nm.The lamp consist of hydrogen under pressure.Deuterium lamp It is similar to hydrogen discharge lamp, but filled with deuterium in the place of hydrogen.It offers 3-5 times more intensity than other types.This is most widely used but expensive.Xenon discharge lamp In this lamp , xenon at 10-30 atmospheric pressure is filled in and has two atomic number 74 electrodes. The intensity is greater than hydrogen discharge lamp.Mercury arc This contains hectogram vapour and offers bands which are sharp.The spectrum is not continuous.MonochromatersGrating monochromaters are used, filters and prism monochromaters are not used because of low resolution.On the other hand gratings provide a band pass of 0.4 to 2nm.Hence they are more widely used incase of expensive spectrophotometers.The mirrors ,gratings are made up of quartz since glass clears uv radiation from 200-300nm.Mirrors are front surfaced to prevent absorption of radiation. test CellsThe design of sample cells used is similar to that used in colorimetric analysis expect that it is made up of quartz. Quartz cells only must be used in uv spectroscopy since glass cells will absorb uv radiation.The pathlength of the cells are 10mm or 1cm.Solventssolvent plays an important role in uv spectra, since compound peak could be obscured by solvent peak.Hence the solvent for a sample is selected in such a way that solvent neither absorbs in the region of measurement nor affects the absorption of the sample.DetectorsAlthough any one of the detectors used in colorimetry can be used, photomultiplier tubes are mainly used, since the cost of such UV spectrophotometers are high and more accurate measurements are to be made.Single beam and double beam UV spectrophotometers are used.7.3.Beers jurisprudence (related to assiduity of absorbing species)Beers law states that the intensity of beam of monochromatic light decreases exponentially with increase in the concentration of absorbing species arithmetically.Lamberts law (related to thickness/ path length of absorbing species)Lamberts law states that the rate of decrease of intensity (monochromatic light) with the thickness of the medium is right away relative to the intensity of incident light.Beer-Lambert LawThe beer lamberts law states that abs orbance of a solution is directly proportionally to the concentration of the solution.A = log_10(I/I_0) = epsiloncdot ccdot L,The beer-lambert law is useful for characterizing of the compounds but does not hold as a universal relationship for the concentration and absorption of all species.ApplicationsIt is mainly used in the detection of impurities.It is used in the structure elucidation of organic compounds.And also used in the analysis of organic compounds.Detrmination of molecular weight.Determination of dissociation constant of acids and bases.7.4 Flow through dissolution apparatusThe time period-through cell is a suitable method for dissolution studies of poorly soluble drugs. The dissolution can be influenced by changing parameters in the apparatus and by changing the physical properties of the drug and the medium used. In this study the dissolution of ibuprofen was examined. Results showed that a littler particle size gave a higher dissolution rate. With a dose of 50mg a hi gher percent dissolved was obtained compared to a dose of 100mg. However, a larger mass (mg) was dissolved when the dose of 100mg was used. When using a cell diameter of 12mm instead of a cell diameter of 22.6mm the dissolution rate increased. A larger dissolution rate was also obtained when the flow of the medium was increased. Finally the effect of changing medium was examined. Results showed that by including a surfactant to the medium a drastic increase of the dissolution rate was obtained.The flow-through cell has since the 90s been used as an alternative method for dissolution studies . It has some advantages over previous dissolution methods. It is easier to retain sink condition, i.e. to keep a sufficiently low concentration in the remaining solution. This makes it possible to keep a constant diving force (=concentration difference) the whole time during the release experiment. The concentration should not exceed one third of the saturated. The medium can be changed automati cally during the study which is very useful in in vitro in vivo studies . Previous studies have showed the importance of deaeration of the dissolution medium, how the packing of the cell can influence the dissolution and that the results obtained with the flow-through cell are more ordered than obtained with previous methods as dissolution bathsIn this study the dissolution of ibuprofen was examined in the flow-through cell. Six parameters were of interestThe packing of the cellThe particle size of the drugThe doseThe volume flow of the medium through the cellThe cell diameterThe mediumDesirable results were good reproducibility, i.e. small beat deviation between tests and cells, and to maintain sink condition during the experiment.Advantages Laminar flow characteristics over a wide range of solvent flow ratesInfinite sink ideal for low solubility drugsDifferential rather than cumulative time profile o