Patent Application: US-201113704382-A

Abstract:
the invention “ colloidal nanoscale carriers for active hydrophilic substances and method for producing same ” pertains to the field of medical , odontological or hygiene preparations , and is characterized by structures formed by hydrophilic polymers that contain active hydrophilic substances coated with a non - hydrophilic phase and surfactants with affinity for the components , forming an invert emulsion that allows the incorporation and controlled delivery of active hydrophilic substances , conferring properties such as protection against degradation processes , improvement of compatibility with the other components of the formulation in the final product , increase in the availability and / or bioavailability of the active substance in the medium of interest and controlled release of the active substance . the nanoscale carrier obtained by this method , called colloidal nanoscale carrier , can be used in various fields , such as the pharmaceutical field , cosmetics , personal hygiene products , veterinary medicine , agrochemicals and fertilizers , the food industry and the like . the invention proposes a kinetically stable system with an effective nanoscale structure that consists of nanoscale carriers formed by polymers emulsified in a non - aqueous medium in the presence of a surfactant with affinity for the two phases . this system is obtained by nanoemulsification of an aqueous phase of hydrophilic polymers emulsified in a non - hydrophilic phase that contains the surfactants , and is characterized by the implementation of two concepts that encompass the generation of an invert nanoscale emulsion and of polymer nanoparticles . the formulation has the novel technical effect of providing a polymer excipient with a nanoscale structure for delivering hydrophilic molecules suspended in a non - hydrophilic phase , which allows controlling the size of the nanoscale particles and modulating colloidal stability by means of process parameters .

Description:
the development of a system for delivering nanostructured actives , seeking improved stability and increased bioavailability , is a challenge of the science of colloids covering numerous applications , ranging from the placement of drugs with site - specific action , the skin permeation of hydrophilic compounds to cellular internalization of particles . faced with these challenges many systems have been considered in recent years , but many have limitations with respect to an action potent and stable for a given application . nanoparticles have the advantage of having a solid matrix that holds the active component and may modulate their release . the solid state of these materials gives them a reduced permeability to containing species . moreover , the solid particles lipid - based reduce any limitation due to toxicity problems . these materials are certainly effective for the encapsulation of hydrophobic molecules , but are limited to ensure vectoring hydrophilic species , or for any application requiring aqueous internal compartment . the crystallizable double emulsions systems would also be very viable for the placement of hydrophilic active , having as limiting the warming issue during the preparation as well as polymeric nanoparticles . the nanoemulsions have emerged as the ideal candidate for the application in question , but regarding the incorporation of hydrophilic molecules and possessing degradation in aqueous medium , there was a need for creating an inverse emulsion or even anhydrous , which avoided its degradation . the nanocarrier discussed herein is thus resulting from the design of a new system kinetically stable and effective in the nanostructure . this new nanocarrier consists of structures formed by hydrophilic polymers containing hydrophilic active , surrounded by a hydrophilic phase and surfactants not having attraction for the components , forming an inverse emulsion formed by polymer emulsified in a non - aqueous medium in the presence of a surfactant which has attraction between the two phases ( the dispersing medium and encapsulating agent ). employing hydrophilic polymers dissolved in the aqueous phase and emulsified in a non - aqueous phase containing the surfactant , this design combines both concepts covering the generation of a nanoemulsion and an inverse polymeric nanoparticles . the new system is called colloidal nanocarrier ( nc ) and consists of a polymeric colloidal nanocarrier that enables controlled placement and incorporation of active hydrophilic formulated in a non - aqueous external phase . some inventions have been patented using nanoparticles and carrier , however , mostly refers to the development and implementation of carriers for hydrophobic molecules , also using hydrophobic encapsulating matrix , eg , block copolymers , and still employing various processes , and in neither case is used in obtaining the inverse emulsion nanocarriers , this is basically the novelty and inventiveness of the colloidal nanocarriers for hydrophilic actives and their production process that are object of this patent application . document wo 2009123768 “ nanocarrier and nanogel compositions ,” describes a class of carriers in the nanometer range consisting of block copolymers suspended in an aqueous solvent or co - polymer ( in a different way to the invention disclosed herein ) associated with therapeutic agents hydrophobic character , and as examples tested were employed indomethacin , doxorubicin and budesonide , among others . another composition , presented in document wo 2007041206 “ drug delivery nanocarriers targeted by phase landscape ” describes method of obtaining nanocarriers by employing amphiphilic molecules for encapsulation , particularly site - specific protein , using only the technique described complexation . the carrier is formed by a phase protein containing a protein that exhibits a peptide linker selected to bind specifically and selectively to a target site , which is released . however , the invention only claims specific proteins , including non - hydrophilic molecules or as polymer matrices employing nanocarrier . documents kr 100868724 “ method for preparing self - aggregating nanocarrier particles having temperature depending property ” and wo 2009123934 “ branched multifunctional nanoparticle conjugates and their use ” also describe carrier nanoparticles for hydrophobic agents . in the first case ( kr 100868724 ), the inventors use block copolymers that are temperature sensitive for the incorporation of drugs , and control of particle formation by means of temperature . the process involved comprises a polymerization step and employs sensitive polymers containing a group of poly ( n , n - dimethylacrylamide ), poly ( n - isopropyl acrylamide ) or mixture thereof . in the case of wo 2009 / 123934 , the matrix is composed of branched polymers polyglycerol with specific action “ mount and unmount ” in vivo conditions , coupled with a hydrophobic agent . these systems are often employed in imaging and diagnostic procedures , such as in cancer models . the wo 2009055794 document “ method and compositions for therapeutic molecules containing polymer nanocarriers ” describes a method and a composition nanocarriers formed by block copolymers of hydrophobic obtained by the double emulsion process for encapsulation and delivery of proteins . the application comprises the use of this filamentous and spherical nanoparticles carrier for diagnostics and therapeutics . document wo 2009141 170 “ suitable nanocarriers for active agents and their use ” discloses a carrier body which has in its structure a grouping defined by formula amine as a residue . the invention relates to compounds such as carrier for nucleotides , nucleosides , oligonucleotides linear or circular single or double and oligomeric molecules ( being all of these hydrophobic molecules ), with a shell consisting of polyglycerol and / or derivatives , with the main field of interest being the silencing genes . the processes for the obtention of non nanocarriers consists in reverse emulsion , such as the invention herein disclosed , but rather a conventional emulsion ( oil / water ) to the airing of hydrophobic actives . the prior art work that presents some respects similar to the present invention is document u . s . 2009 / 0258078 “ antioxidant polymer nanocarriers for use in preventing oxidative injury ” which is characterized by the presence of a carrier polymer for encapsulation of proteins prepared by homogenization temperature below zero , thus maintaining the enzyme activity . may be employed xenobiotic detoxifying enzymes and antioxidants , which are preserved from degradation of proteases , increasing their lifespan . one advantage is that the system is permeable to substrate and can exert its effect without release of the encapsulated enzyme . the present invention “ colloidal nanocarriers for hydrophilic actives and their production process ” employs a nanocarrier for molecules hydrophilic properties ( and not protein ), suspended in a non - aqueous medium and obtained by a method that includes three stages : pre - emulsification , extraction and nanoemulsification of the internal phase ( solvent ), by means of a double - emulsion process . the nanocarrier formed for hydrophilic agents also protects against degradation and may protect including molecules susceptible to degradation in aqueous medium and non - enzymatic action as in document u . s . 2009 / 0258078 . in addition , there is provided the controlled - release profile of the nanocarrier colloidal which can be modulated as a function of active agent employed , differently to the aforementioned invention , wherein the encapsulated protein remains coupled with the carrier to exert its effect , not being released . the present invention “ colloidal nanocarriers for hydrophilic actives and their production process ” presents a polymeric nanocarrier system formation and structure well defined , and the production process developed specifically for the limitations found in all works presented here , which is the encapsulation agents hydrophilic simply , in a single emulsification process ( without the use of double - emulsion ), and even using inert materials , biodegradable and even in some cases . the manufacturing process of the ncs preparation involves three steps : step 1 being the pre - emulsification step , whilst step 2 and step 3 are nanoemulsification and extraction of the internal phase , as shown in fig2 , the ncs disclosed herein being obtained by emulsification of a hydrophilic polymers containing aqueous solution with the active principle of interest , such polymers are polysaccharides , protein of animal or vegetable origin , chitosan , gum ( arabic gum , xanthan gum , guar gum , carrageenan gum , cashew gum , tara gum , tragacanth gum , karaya gum , gati gum ), cellulose derivatives ( carboxymethyl cellulose , carboxyethyl cellulose , etc . ), polyvinylpyrrolidone , polyacrylates , polyacrylamides , polivinilcaprolactamas in a hydrophilic phase not containing emulsifying agents compatible with the specific hydrophilic phase not chosen . this phase cannot be made hydrophilic by both lipophilic or silophilic liquids . the emulsification process can be carried out by various conventional techniques , such as mechanical stirring , cowlles , ultraturrax , high - pressure homogenizers , ultrasound , or any other technique that will promote the emulsification of an aqueous phase in a nonaqueous environment . step 1 . formation of the pre - emulsion by dispersing the internal phase in the external phase under mechanical stirring and after complete addition , use of conventional stirrer . in this first step is pre - emulsion formed between the inner and outer phase , the inner phase being composed of polymer and an aqueous solution containing an inorganic salt ( water soluble salts ) which function as co - stabilizer and the active hydrophilic , while the external phase contains the non - hydrophilic component and a specific emulsifier such as silicone - modified polioxydethylene ( sf1540 , momentive ®) or other customary emulsifiers compatible . the temperature employed in this step of the process may vary from 10 to 100 ° c ., preferably 25 . 0 ° c . the mixture is held under stirring , which can vary from 100 to 22 , 000 rpm , preferably 1000 rpm and under atmospheric pressure . the salts used should be water soluble , preferably chlorides that are mono - or bivalent . step 2 . homogenizing the pre - emulsion formed in step 1 in a system of high energy mix of disaggregation . the use of high pressure homogenization must employ a minimum of one cycle of homogenization up to the amount required to achieve the desired particle size , generally below 20 cycles , the temperature employed in this step can vary from 10 to 100 ° c ., preferably 25 . 0 ° c . the pressure equipment must be at least 10 bar and maximum capacity of the pressurizing device , preferably 900 bar . step 3 . the resulting nanoemulsion is placed in a reactor with reduced pressure with controlled temperature and mild agitation was connected to a condenser for extraction of the internal aqueous phase and formation of ncs . this step of extracting the solvent of the internal phase should be performed for at least 15 minutes to the time required for dehumidification desired , usually 5 hours , and the pressure applied may vary from 760 mmhg to 10 - 7 mmhg , preferably 280 mmhg . the reactor temperature in this step can vary from 20 to 150 ° c ., 50 ° c . being the preferred temperature . to illustrate some embodiments of the invention and the potential application of ncs are examples employing different active hydrophilic , and the main characteristics of the products obtained , including the release profile and encapsulation efficiency . the ncs were characterized as the water content , refractive index , mean particle diameter , polydispersity , viscosity , turbidity dynamics and morphology . in a 500 ml beaker was prepared a solution containing 140 g of an emulsifier - based silicone - modified polioxydethylene ( sf1540 , momentive ®) in the concentration dimethicone 3 % m / m . another solution was prepared by dissolution of 9 g of starch and 0 . 6 g nacl in 51 g of deionized water . the aqueous starch solution was emulsified in the hydrophilic phase not under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization for five cycles at a pressure of 900 bar . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum , at pressure of 280 mmhg . the water removal was conducted for 3 hours and 5 hours in dehumidifying 50 ° c . the ncs were characterized as the average particle diameter ( dp ), polydispersity index ( pi ), residual water content ( ta ), viscosity ( visc ), turbidimetry and dynamic morphology . the results are shown in table 1 . the results of pd , pi and at reported in table 1 refer to ncs obtained in times 3 hours and 5 hours of water extraction process and certify the ownership of nanometer carrier system , with relatively low polydispersity index , and the content of reduced water as a function of time . furthermore , the system has generated characteristic of fluid , as can be seen by the low viscosity displayed . the morphology spherical and smooth surface , regular nc obtained can be seen in fig3 . in a 500 ml beaker was prepared 140 g of a solution containing an emulsifier to the silicone - modified polioxydethylene ( sf1540 , momentive ®) in the concentration dimethicone 3 % by mass . another solution was prepared by dissolution of 9 g of pvp and 0 . 6 g nacl in 51 g of deionized water . the water solution of pvp was emulsified in the hydrophilic phase not under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization with five cycles at 900 bar pressure . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum ( 280 mmhg ). the water removal was conducted for 3 hours and 5 hours in case of temperature of 50 ° c . the ncs obtained in this example were characterized as the average particle diameter ( dp ), polydispersity index ( ip ), residual water content ( ta ), viscosity ( visc ), refractive index ( ir ), turbidimetry and dynamic reduction profile size as a function of water content . the results are shown in table 2 . the results of ncs - based pvp were similar to those described for starch ncs shown in example 1 . the values of pa and ta pi described in table 2 refer to ncs obtained at times 3 hours and 5 hours of water extraction process and confirm the property of nanometer - carrier system consisting of pvp , with relatively low polydispersity and reduced water content as a function of time . moreover , the generated system has a characteristic of fluid , as can be seen by the low viscosity displayed . it is emphasized that , controlling the step of extracting water from the internal phase , it is possible to modulate the particle size of the nanocarriers formed , reaching the level of desired diameter as shown in fig4 a . the results show that it is necessary to obtain a given quantity of water to obtain nanostructured systems , from which no further significant variation occurs in size , which can interfere with the physical stability , which can be observed by turbidimetry dynamic as shown in fig4 b . the ncs - based pvp obtained with 3 hours of dehumidification were analyzed for backscatter profile ( by turbidimetry dynamic ) for 7 days after preparation , and showed high physical stability . obtaining the cn based on chitosan was performed in a 500 ml beaker was prepared where 140 g of a solution containing an emulsifier to the silicone - modified polioxydethylene ( sf1540 , momentive ®) in the concentration dimethicone 3 % m / m . another solution was prepared by solubilizing 1 . 2 g chitosan and 0 . 6 g nacl in 51 g of deionized water . the aqueous chitosan solution was emulsified in the hydrophilic phase not under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization with five cycles at 900 bar pressure . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum of 280 mmhg . the removal of water was carried out for 3 to 5 hours at 50 ° c . ncs obtained in this example were characterized as the average particle diameter ( dp ), polydispersity index ( pi ), residual water content ( ta ), viscosity ( target ), turbidimetry dynamic profile morphology and size reduction as a function of water content as shown in table 3 . the characterization of chitosan - based ncs with respect to particle diameter shows a system to obtain nanometer - scale , low polydispersity index and water content lower than 1 , 0 % to 5 hours of extraction . the system obtained has characteristic of high fluidity owing to low viscosity . in this example also observed the formation of spherical nanocarrier structures , with regular surface , as shown in fig5 a . this confirms the possibility of modulation of particle size as a function of the water content present in nanocarriers , variance shows that even a level of nanometer scale , does not result in major reductions in size subsequently , as can be seen in fig5 b . this modulation is associated yet nanocarriers physical stability of the suspension , which with 3 hours of extraction process is kinetically stable and 5 hours have reduced water content , it maintains the property nanometer , but exhibits phase separation , although this is easily redispersed . fig5 c shows the profiles of physical stability of this product with 3 and 5 hours of dehumidification process , and table 4 shows the levels of dynamic stability obtained by turbidimetry , in which case the lower the index , the greater the physical stability of the system . the nc obtaining the starch - based , containing an active model ( sodium salicylate — sana ) was performed in a 500 ml beaker was prepared where 140 g of a solution containing an emulsifier to the silicone - modified polioxydethylene ( sf1540 , momentive ®) in the concentration dimethicone 3 % m / m . another solution was prepared by dissolution of 9 g of starch and 0 . 6 g nacl and 2 g of sodium salicylate in 49 g of deionized water . the aqueous starch and active was not hydrophilic phase emulsified under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization through five cycles at 900 bar pressure . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum of 280 mmhg . the removal of water was carried out for 3 and 5 hours of extraction process at a temperature of 50 ° c . ncs obtained in this example were characterized as the average particle diameter ( dp ), polydispersity index ( pi ), residual water content ( ta ), viscosity ( target ) encapsulation efficiency ( ee ), turbidimetry dynamics and morphology , which results are shown in table 5 . the dp data , shown in table 4 , confirm the nanometer scale of the ncs starch - based embedded with sana , and are in the same size range of ncs starch without active ( example 1 ), indicating that the presence of the molecule not altering the size characteristics of the nanocarriers . nevertheless , the polydispersity index is also low , and the water content in the process times 3 and 5 hours dehumidification also reproduce those of ncs without active ( example 1 ), being reduced to values below 1 , 0 to 5 % hours of extraction . the system has also generated a fluid , confirmed by low viscosity . with the product obtained in this example , the encapsulation efficiency of the remedy the starch matrix showed a value of 93 . 70 %, which demonstrates the feasibility of using the ncs in the encapsulation of hydrophilic active . it is observed in fig6 a and 6b that the ncs consisting of starch and sana containing as active model showed an irregular surface with multiple protrusions on the surface of the particles , like granules active . this morphology shows that the asset is probably encapsulated distributed in the polymer matrix , with preferential location in the outermost portion of the matrix . it is assumed that during removal of the internal phase through the vacuum extraction process sana , which has high solubility in water , migrate to the surface of the particles and becomes more trapped in the outermost layer , solidifying the water content final ( less than 1 , 0 %) and forming small beads visible . obtaining the cn based on pvp containing an active model ( sodium salicylate — sana ) was performed in a 500 ml beaker was prepared where 140 g of a solution containing an emulsifier to the silicone - modified polioxydethylene ( sf1540 , momentive ®) in the concentration dimethicone 3 % m / m . another solution was prepared by dissolution of 9 g of pvp , 0 . 6 g nacl and 2 g of sodium salicylate in 49 g of deionized water . the aqueous solution of pvp and active was emulsified in the hydrophilic phase not under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization with five cycles pressure of 900 bar . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum of 280 mmhg . the removal of water was carried out for 3 to 5 hours ( nc5 - nc5 - 3 h and 5 h ) at a temperature of 50 ° c . ncs obtained in this example were characterized as the average particle diameter ( dp ), polydispersity index ( pi ), residual water content ( ta ), viscosity ( target ), turbidimetry and dynamic encapsulation efficiency ( ee ), and the results are shown in table 6 . similarly to the previous examples , the ncs - based pvp containing as active sana dp model presented at the nanoscale , low polydispersity , reducing water content up to the time of extraction process , with values below 1 , 0 % to 5 hours low viscosity process and indicating the fluidity of the system . fig7 shows the profiles of physical stability of this product with 3 and 5 hours of water extraction process as well as the stability indices obtained by varying the backscattering as a function of time as shown in table 7 ( data obtained by turbidimetry dynamics ). ncs with 3 hours show a much lower stability index ( greater stability ) compared to those from 5 - hour extraction process , indicating a change in the physical stability of the system with the water content present . the nc obtaining starch - based , containing an active model ( cyanocobalamin ) was performed in a 500 ml beaker was prepared where 140 g of a solution containing an emulsifier to the silicone - modified polioxydethylene ( sf1540 , momentive ®) in dimethicone concentration 3 % m / m . another solution was prepared by dissolution of 8 . 1 g starch , 0 . 6 g nacl and 0 . 9 g of sodium salicylate in 51 g of deionized water . the aqueous starch and active was not hydrophilic phase emulsified under mechanical agitation of 1000 rpm . after this emulsification , the mixture was subjected to high pressure homogenization with five cycles at 900 bar pressure . finally , the emulsion was brought to a jacketed glass reactor to effect the removal of water by distillation under vacuum of 280 mmhg . the removal of water was carried out for 3 to 5 hours at 50 ° c . the ncs obtained in this example were characterized as the average particle diameter ( dp ), polydispersity index ( pi ), residual water content ( ta ), refractive index ( ri ), viscosity ( target ), turbidimetry dynamics and morphology , as shown in table 8 . in this example demonstrates the incorporation of a hydrophilic active use food , pharmaceutical and veterinary ncs in starch based . the product obtained in the experimental conditions of this example dp presented at the nanoscale , low polydispersity , reducing water content with time dehumidification process , with values below 1 , 0 % to 5 hour process and low viscosity indicating the fluidity of the system . the encapsulation efficiency also resulted in a large value ( approximately 89 %) demonstrating the performance of the array nanocarriers in the incorporation of hydrophilic molecules . the profile of controlled release of active models of ncs , relating to examples 4 and 6 was monitored in a 48 hours period , by measuring the uv absorption in the wavelengths of 232 nm to 301 nm to cyanocobalamin and sodium salicylate . a mass of about 150 g of the formulation was applied to a membrane and immersed in closed flasks , to which were added 100 . 0 ml of water . the system was kept under gentle stirring ( 50 rpm ) and heated to 37 ° c . there were collected 3 . 0 ml aliquots at intervals of predetermined time and the concentrations monitored by uv absorption . the percentage of active released was plotted against time ( in hours ) with their standard deviations . the release assay was performed in triplicate and reading of absorption measurements in quintuplicate , as can be seen in fig9 . it is observed that the ncs containing sodium salicylate showed a release profile faster than those containing cyanocobalamin . these differences in the release profile may be attributed to differences in molecular structure and solubility of the molecules ( hydrophilic active ) in water , besides the interaction that each has with the polymeric matrix . 1 . arruebo , m ., fernández pacheco , r ., ibarra , mr ; santamaria , j . magnetic nanoparticles for drug delivery , nano today , v . 2 , p . 22 - 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