unless defined otherwise , all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs . also , all publications , patent applications , patents , and other references mentioned herein are incorporated by reference . as used herein , all percentages are by weight unless otherwise specified . in addition , all ranges set forth herein are meant to include any combinations of values between the two endpoints , inclusively . as used herein , the term “ immediate release ” shall mean that the dissolution of the dosage form conforms to usp specifications for immediate release tablets containing the particular active ingredient employed . for example , for ibuprofen tablets , usp 35 specifies that in ph 7 . 2 phosphate buffer , using usp apparatus 2 ( paddles ) at 50 rpm , at least 80 % of the ibuprofen contained in the dosage form is released within 60 minutes . see usp 35 - nf 302012 ibuprofen tablets monograph and general chapter & lt ; 711 & gt ;. time release technology , also known as sustained - release , is a mechanism used in tablets or capsules to dissolve slowly and release a drug over time . the advantages of sustained - release tablets or capsules are that they can often be taken less frequently than immediate - release formulations of the same drug , and that they keep steadier levels of the drug in the bloodstream . the term , “ good mouth feel ” shall mean the general sensory experience by the consumer during and after the oral consumption of the dosage form , including , but not limited , by chewable forms or and suspensions . the term , “ burn ” is understood to mean the commonly identified peppery or irritating sensation in the throat and / or mouth , often noted when taking low melting propionic acid derivative compounds such as ibuprofen and related compounds . this burn is different than bitterness inasmuch as the addition of a sweetener is not effective in reducing the sensation . the burn can be expressed as a throat catch , or as a sudden cough reflex that results from the irritation . propionic acid derivatives are a well known class of analgesic compounds . as used herein propionic acid derivatives are understood to include , but are not limited to , ibuprofen , naproxen , benoxaprofen , naproxen sodium , flurbiprofen , fenoprofen , fenbuprofen , ketoprofen , indoprofen , pirprofen , carpofen , oxaprofen , pranoprofen , microprofen , tioxaprofen , suproprofen , alminoprofen , tiaprofenic acid , fluprofen and bucloxic acid . the structural formula is set forth in u . s . pat . no . 4 , 923 , 898 , which is hereby incorporated by reference . propionic acid derivatives as defined herein are defined as pharmaceutically acceptable analgesics / non - steroidal anti - inflammatory drugs having a free — ch ( ch 3 ) cooh or — ch 2 ch 2 cooh or a pharmaceutically acceptable salt group , such as — ch ( ch 3 ) coo — na + or ch 2 ch 2 coo — na +, which are typically attached directly or via a carbonyl functionality to an aromatic ring system . typical adult daily dosage of over the counter ibuprofen , a propionic acid derivative , is 200 mg to 1200 mg , with daily prescription dosage ranging up to 3200 mg / day . ibuprofen is a widely used , well known non - steroidal anti - inflammatory propionic acid derivative . ibuprofen is chemically known as 2 -( 4 - isobutylphenyl )- propionic acid . as used herein ibuprofen is understood to include 2 -( 4 - isobutylphenyl ) propionic acid as well as the pharmaceutically acceptable salts . suitable ibuprofen salts include , for example , sodium , arginine , lysine , histidine , as well as other salts described in u . s . pat . nos . 4 , 279 , 926 , 4 , 873 , 231 , 5 , 424 , 075 and 5 , 510 , 385 , the contents of which are incorporated by reference herein . the formulation of the present invention may also contain pharmaceutically acceptable excipients , fillers , flavors , diluents , lubricants , disintegration agents , suspension agents , stabilizers , binders , colorants , carriers and the like . for example suitable carriers include lactose , starch , dicalcium phosphate , calcium sulfate , kaolin , mannitol and powdered sugar . typical binders include starch gelatin , sugars ( such as dextrose , mannitol , xylitol , sorbitol , maltodextrins , fructose , sucrose , molasses ), and lactose , polyvinylpyrrolidone , polyethylene glycol , ethyl cellulose and waxes . lubricants include boric acid , sodium benzoate , magnesium stearate , sodium acetate , sodium chloride , leucine , polyethylene glycol and the like . typical disintegrants include , starch derived from wood , maize , potato , and rice , methylcellulose , magnesium silicates , aluminum silicates , sucrose , dextrose , maltodextrin , agar , alginic acid , wood products , guar gum , citric pulp , sodium lauryl sulfate and the like . the present invention may be provided in liquid or semi - solid form , e . g ., an elixir , suspension , syrup , gel , cream , ointment , or sugar cream confection such as a fondant or nougat . the liquid or semi - solid formulations are prepared using manufacturing methods and pharmaceutically acceptable surfactants , dispersants , sweeteners and diluents known in the art . preferably the present invention is provided in tablets or other solid dosage forms and most preferably in a chewable form . the invention will now be illustrated by , but is not intended to be limited to , the following example . in the example , it is understood that unless noted otherwise , all parts are weight percent . specific embodiments of the present invention are illustrated by way of the following examples . this invention is not confined to the specific limitations set forth in these examples . preparation of melted taste - masked particles containing ibuprofen with a ratio of drug : glyceryl behenate of 85 : 15 approximately 85 g of ibuprofen usp and 15 g of glyceryl behenate , which is commercially available as compritol ato 888 , from the gattefosse corporation in lyon , france , were added to a suitable vessel while mixing with a laboratory mixer at appropriate speed and heated to 80 - 90 ° c . until both ingredients melt . 200 g of purified water is added to a second suitable stainless steel vessel and heated to approximately 80 - 90 ° c . while mixing , the molten ibuprofen and glyceryl behenate mixture is added to the hot water . the dispersion of molten mixture of ibuprofen and glyceryl behenate and hot water is then added to a separate vessel containing 200 g of cold water ( less than 10 ° c .) while mixing to congeal the ibuprofen / wax droplets . the resulting particles were filtered through a suitable stainless steel mesh screen , collected and dried at room temperature overnight in a desiccator . the resulting particles have a mean particle size range between 170 and 250 microns . preparation of chewable tablet comprising taste - masked ibuprofen particles from example 1 the dried taste - masked ibuprofen particles from example 1 , and the materials in the table below were blended together in v - blender and compressed using a rotary tablet press to a hardness of 4 - 7 kp . utilizing the formula in table 2 , an in - situ taste - masked ibuprofen suspension was prepared . ibuprofen and glyceryl behenate were melted in a 1500 ml glass beaker “ a ” at 80 - 90 ° c . in beaker “ b ”, citric acid and part xanthan gum were dissolved in about 300 ml purified water heated to 80 - 90 ° c . contents of beaker b were added to the molten ibuprofen / wax combination in beaker a under continuous stirring . the temperature of beaker a was maintained at 80 - 90 ° c . the water in part ii was at room temperature and placed in a third beaker “ c ” and cooled down to less than 10 ° c . once the ibuprofen and the glyceryl behenate formed a uniform dispersion in water , the mixture was removed from the water bath and hotplate . the contents of beaker c were poured into beaker a and slowly and continually stirred at 1000 - 1500 rpm , as the molten ibuprofen and glyceryl behenate mixture congealed into fine particles . xanthan gum ( from part iii ) was poured into glycerin and added to the mixture in beaker a . the remaining ingredients from part iii were added into beaker a , and mixed for 5 minutes . the resultant suspension was stored in a suitable labeled container . approximately 70 g of ibuprofen usp ( 70 μm grade ) and 30 g of glyceryl behenate , which is commercially available as compritol ato 888 , from the gattefosse corporation in lyon , france , were added to a suitable vessel while mixing with a laboratory mixer at approximately 50 rpm and heated to 80 - 90 ° c . 200 g of purified water is added to a second suitable stainless steel vessel and heated to approximately 80 - 90 ° c . while mixing . the ibuprofen and glyceryl behenate mixture is added to the hot water while mixing . the melted mixture of ibuprofen and glyceryl behenate and hot water are then added to a separate vessel containing 200 g of cold water ( less than 10 ° c .) while mixing . the resulting particles were filtered through a 100 mesh stainless steel screen , collected and dried for 6 hours at 30 ° c . the resulting particles have a mean particle size range between 170 and 250 microns . approximately 50 g of ibuprofen usp ( 70 μm grade ) and 50 g of glyceryl behenate , which is commercially available as compritol ato 888 , from the gattefosse corporation in lyon , france , were added to a suitable vessel while mixing with a laboratory mixer at approximately 50 rpm and heated to 80 - 90 ° c . 200 g of purified water is added to a second suitable stainless steel vessel and heated to approximately 80 - 90 ° c . while mixing . the ibuprofen and glyceryl behenate mixture is added to the hot water while mixing . the melted mixture of ibuprofen and glyceryl behenate and hot water are then added to a separate vessel containing 200 g of cold water ( less than 10 ° c .) while mixing . the resulting particles were filtered through a 100 mesh stainless steel screen , collected and dried for 6 hours at 30 ° c . the resulting particles have a mean particle size range between 170 and 250 microns . preparation of melted taste - masked particles containing ibuprofen with a ratio of drug : glyceryl behenate of 85 : 15 , alternate mixing process approximately 85 g of ibuprofen usp ( 70 μm grade ) and 15 g of glyceryl behenate , which is commercially available as compritol ato 888 , from the gattefosse corporation in lyon , france , were added to a suitable vessel while mixing with a laboratory mixer at approximately 50 rpm and heated to 80 - 90 ° c . 200 g of purified water of water preheated to 80 - 90 ° c . is added to the mixture while mixing . 200 g of cold water ( less than 10 ° c .) is then added to the same vessel while mixing . the resulting particles were filtered through a 100 mesh stainless steel screen , collected and dried for 6 hours at 30 ° c . the resulting particles have a mean particle size range between 170 and 250 microns . the chewable tablets from example 2 , containing the taste masked immediate release ibuprofen particles are tested for dissolution using usp apparatus ii . the dissolution medium was 900 ml of ph 7 . 2 phosphate buffer with paddle speed of 50 rpm . the dissolution data is presented in table 3 and fig1 . sustained release ibuprofen particles from example 4 , part a ( 70 : 30 ibuprofen : glyceryl behenate ) and example 4 - part b ( 50 : 50 ibuprofen : glyceryl behenate ) are also analyzed for dissolution using the same equipment over 10 hour period for ibuprofen content versus a standard prepared at 100 % theoretical concentration . the dissolution data is shown in table 4 and fig2 .
low melting propionic acid derivative particles that are free flowing and have significantly reduced or eliminated throat burn are disclosed . a method of manufacturing the low melting propionic acid derivative particles ; dosage forms containing the low melting propionic acid derivative particles ; methods of manufacturing the dosage forms ; and methods of treatment using the dosage forms are also disclosed .