HK1178029A - Formulations and methods for nutrient delivery - Google Patents

Description

Nutrient delivery formulation and method

Technical Field

The present application relates to improved enteral nutritional formulations containing one or more of arginine, glutamine, docosahexaenoic acid (DHA), and arachidonic acid (ARA), and methods of providing low-volume nutritional support in water-soluble and fat-soluble forms to populations suffering from nutritional deficiencies, such as preterm infants. The liquid nutritional formulations of the present application may contain a highly purified alpha-lactalbumin-stabilized DHA emulsion that may be dispersed into an aqueous component containing nutrients such as arachidonic acid (ARA), arginine, glutamine, arginyl-glutamine dipeptide, alanyl-glutamine dipeptide, other amino acids, vitamins, minerals, and supplemental nutrients, or combinations of the foregoing. The nutritional formulation may be adapted for nasogastric tube feeding, gastric feeding, transpyloric administration, and/or any other mode of administration that results in the introduction of the nutritional formulation into the digestive tract of a subject.

Background

The present application relates to improved enteral nutritional formulations directed to nutritional deficiencies in severely diseased populations and the physiological and other consequences often caused by these deficiencies. In particular, the present application is directed to nutritional deficiencies that may occur in subjects receiving partial or complete parenteral nutrition.

Nutritional support for premature infants is important because short term survival, long term growth and development are problematic. When providing nutritional support to preterm infants, important goals include: increase growth rate and increase nutrients to the extent achieved during fetal development; optimizes the neural development result and lays a strong foundation for long-term health. However, these goals are not easily achieved because severely ill, low birth weight, premature infants often cannot tolerate traditional enteral feeding due to concomitant pathological conditions or immaturity of the intestinal tract and other organ systems. Therefore, Total Parenteral Nutrition (TPN) is the only or preferred method of providing nutritional support. While TPN can save lives, it is not a perfect way of nutritional support. TPN lacks many key nutrients, the limitations of which can have long-term physiological and developmental consequences for infants.

In fact, TPN does not provide valuable nutrients, such as glutamine. Glutamine has traditionally been classified as a "nonessential" amino acid because it can be endogenously synthesized in almost all tissues. Glutamine is important for development because it is the primary source of power for rapidly dividing cells, such as intestinal cells and lymphocytes in the intestine.

Glutamine supplementation is not required for healthy individuals on a normal diet. However, in severely diseased patients suffering from severe catabolism (e.g., severely diseased and/or premature infants), intracellular glutamine stores can become depleted and pathways for biosynthesis often fail to meet the growing demand for tissues that metabolize glutamine. Glutamine is therefore a "conditionally essential" amino acid.

Early-maturing infants face a sudden loss of placental glutamine supply at early parturition. In addition, such infants are often severely ill and face numerous physiological stresses that can rapidly deplete their available glutamine reserves. This problem is exacerbated by the lack of glutamine in parenteral nutrition and TPN amino acid solutions. Parenteral nutrition sources often lack glutamine due to its instability in solution.

Also, there are several factors that put premature infants receiving TPN support at risk for arginine deficiency. Arginine is an essential amino acid for maximal growth in immature mammals. L-arginine is synthesized from glutamine, glutamic acid, and proline through the gut-renal axis in the human body. More specifically, citrulline is synthesized by glutamine, glutamic acid, and proline in mitochondria of intestinal cells in the intestine, is released from the small intestine, and is taken up mainly by the kidney for the production of arginine. In human infants, most citrulline synthesized in intestinal cells is converted to arginine in situ. L-arginine is a substrate for the synthesis of Nitric Oxide (NO), a potent vasodilator of the systemic, gastrointestinal and pulmonary circulation. Endothelial Nitric Oxide (NO) is an important regulator of vascular perfusion, and NO plays a role in combating infection and vasodilation, which are involved in the maintenance of mucosal integrity, gut barrier function, regulation of intestinal mucosal blood flow in the face of inflammation or trauma, and normal transition of circulation from fetal to neonatal.

Arginine is also required in the detoxification of ammonia. Thus, life-threatening hyperammonemia may occur in premature infants as a result of arginine deficiency. Premature infants have underdeveloped arginine synthesis pathways and decreased amounts of citrulline in the gut, thereby reducing the ability to produce endogenous arginine, and thus need to supplement their diets with arginine. Importantly, the supplemental arginine prevents hyperammonemia in premature infants receiving TPN.

Furthermore, stress often causes loss of both arginine and glutamine in premature infants undergoing intensive care. (Neu J. Glutamine supplements in prematurity factors: why and how (supplementation of Glutamine in premature infants: cause and method),J Pediatr Gastroenterol Nutr2003, 37(5) 533-. However, as discussed previously, commercial TPN solutions do not contain glutamine, nor sufficient arginine.

However, there is evidence suggesting that arginine is an essential amino acid in premature infants receiving TPN. For example, premature infants with necrotic enteritis and persistent pulmonary hypertension have reduced plasma arginine concentrations, and arginine availability may be an important factor limiting NO formation within this population. Plasma L-arginine levels have been shown to be low in premature infants and to be associated with respiratory distressThe severity of the urge syndrome is correlated. Plasma L-arginine in premature infants was also found to be low when necrotic enteritis was diagnosed. Therefore, Arginine supplementation of infants with low birth weight shows a decrease in the level of necrotic enteritis, possibly due to increased local nitric oxide production via the L-Arginine-nitric oxide synthesis pathway, thereby improving the blood flow of the intestinal microvasculature (Amin HJ, Zamora SA, McMillan DD, Fick GH, butkner JD, Parsons HG, Scott RB. Arginine supplementation with predictions and necrotizing enterocolitis in the patient agent.J Pediatr2002, 140(4), 425 and 431). And glutamine and arginine supplementation showed safety in both intravenous and enteral glutamine-supplemented multicenter experiments in low birth weight infants (Poindexter BB, Ehrenkranz RA, Stoll BJ, Wright LL, Poole WK, Oh W, Bauer CR, Papire LA, Tyson JE, Carlo WA, Laptook AR, Narendran V, Stevenson DK, Fanaroff AA, Korones SB, Shankaran S, Finner NN, Lemons JA. partial glutamine administration not less than the death rate of very low birth weight infants or sepsis of mortality or one-set diseases in extreme low birth weight mice infections).Pediatrics2004, 113(5), 1209-1215 and Vaughn P, Thomas P, Clark R, New J, Enteral glutamine supplementation and methylation in low birth weights inputs (Enteral glutamine supplementation and incidence in low birth weight infants).J Pediatr. 2003;142(6):662-668.)。

It is well known that proteins are converted to amino acids in the digestive system, and the resulting amino acids are used by the body for growth and development. Proteins and peptides for use in therapeutic or prophylactic measures are also well known. Oligopeptides are better absorbed in the intestinal tract than the amino acids alone. Therefore, arginyl-glutamine or alanyl-glutamine can be used as a dipeptide source of arginine and glutamine rather than the individual amino acids arginine and glutamine to improve the stability of the formulation or due to the improved solubility and absorption capacity of the dimer over the monomer.

TPN and other parenteral nutritional supplements also provide negligible amounts of preformed DHA and ARA. DHA is an omega-3-fatty acid and the most abundant long chain polyunsaturated fatty acid (LCPUFA) in the brain and retina, which is considered essential for proper brain and vision development in infants. Although there is a metabolic pathway for linolenic acid biosynthesis in the diet, which is a bio-energy disadvantage, mammals derive most of their DHA from preformed DHA provided from dietary sources. For infants, the source of DHA is typically human milk; however, parenteral formulations provided to preterm infants are often deficient in DHA.

Parenteral formulations also generally do not provide sufficient levels of arachidonic acid (ARA). ARA is an omega-6 LCPUFA that functions as a structural lipid associated with phospholipids in blood, liver, muscle, and other major organ systems. ARA is synthesized by elongation and desaturation of linoleic acid. However, most ARA must be supplied by the diet. ARA is particularly important in fast physical growth phase and is therefore an important component of infant nutrition.

Many studies have shown that unfulfilled preterm milk supplied to infants provides an unequal amount of several nutrients that do not meet the needs of preterm infants (Davis, d.p., "Adequacy of expressed breast milk for early growth of preterm infants)",Archives of Disease in Childhood52, p.296-301, 1997). Although the exact needs vary among infants due to differences in activity, energy expenditure, efficiency of nutrient absorption, disease, and the ability to utilize energy for tissue synthesis, currently available parenteral nutrition sources are not suitable.

Furthermore, preterm infants often do not tolerate a feeding volume well and nutrients must be provided in acceptable volumes, often by enteral administration. Suitable methods for enteral feeding of preterm infants are based on gestational age, birth weight, clinical condition and the opinion of the attending medical staff. Specific feeding decisions are made based on the infant's ability to coordinate sucking, swallowing, and breathing. Often, premature or immature, weak or badly ill infants need to be fed by intubation to avoid the risk of inhalation and for conserving energy.

Transnasal gastric feeding is commonly used in neonatal intensive care units and may be used in conjunction with bolus infusions (bolus) or continuous infusion fortified human milk or other nutritional supplements. Continuous feeding can be better tolerated by low birth weight infants as well as infants that previously did not tolerate gavage feeding; however, as discussed previously, a reduced or defective nutrient supply is a problem associated with the continuous feeding methods known in the prior art.

Thus, there is a need for stable nutritional formulations and methods that are well tolerated by preterm infants that can be simply administered to subjects suffering from nutritional deficiencies in a form and manner that is readily accepted by the subject and care providers.

Populations (e.g., preterm infants) often suffer from nutritional deficiencies because they are provided a diet lacking the important nutrients described above. Accordingly, there is a need in the art to provide nutritional formulations containing valuable nutrients (e.g., DHA, ARA, arginine, and glutamine) that support infant development. Thus, the nutritional formulations and methods of the present application provide enteral nutritional support to patients suffering from nutritional deficiencies to promote optimal health and development by supplying essential nutrients that are either deficient in known parenteral nutritional formulations or are provided in inappropriate amounts.

Disclosure of Invention

Briefly, therefore, the present application relates to stable nutritional formulations for nutritional deficient subjects (e.g., preterm infants) requiring low volume nutritional support and methods of promoting healthy development in a subject. The present application provides for the administration to a subject of a formulation of fatty acids such as DHA and/or ARA, amino acids such as arginine and glutamine, and other nutrients to prevent the development of a nutritional deficiency or to correct an existing nutritional deficiency.

In one embodiment, the present application includes a nutritional formulation comprising an emulsion of docosahexaenoic acid (DHA) dispersed in an aqueous component comprising at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine, and alanyl-glutamine, and a surfactant comprising highly purified alpha-lactalbumin.

In another embodiment, the present application includes a method of providing nutritional support to a subject, the method comprising administering to the subject a nutritional formulation comprising an emulsion of docosahexaenoic acid (DHA) dispersed in an aqueous component comprising at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine, and alanyl-glutamine, and a surfactant comprising highly purified alpha-lactalbumin.

A further embodiment comprises a method of providing nutritional support to a preterm infant, wherein the method comprises enterally administering to the preterm infant a nutritional formulation comprising an emulsion of docosahexaenoic acid (DHA) dispersed in an aqueous component comprising at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine and alanyl-glutamine, and an emulsifier comprising at least 95% w/w alpha-lactalbumin.

It is to be understood that both the foregoing general description and the following detailed description present embodiments of the application, and are intended to provide an overview or framework for understanding the nature and character of the disclosure as it is claimed. This description is made for the purpose of illustrating the principles and operation of the claimed subject matter. Other and further features and advantages of the present application will be apparent to those skilled in the art upon reading the following disclosure.

Brief description of the drawings

FIG. 1 is a bar graph showing the synergistic effect of administration of Arg-Gln dipeptide and DHA in a mouse model to promote healthy eye development by reducing anterior retinal neovascularization. Figure 1 provides a graphical overview of the analysis of the retinal neovascularization levels in the anterior retina of a mouse model after gavage treatment. The numbers in parentheses refer to gavage doses expressed in grams/kilogram body weight/day. Denotes P value < 0.05.

Best mode for carrying out the invention

Nutritional formulations and methods are provided for providing nutritional support in the form of water-soluble and fat-soluble nutrients to any population suffering from a nutritional deficiency, such as preterm infants. A full and enabling disclosure of the present application, including the best mode thereof to one of ordinary skill in the art, is set forth in the specification, which follows.

The present application also provides improved enteral nutritional formulations that correct nutritional deficiencies and methods of providing enteral nutritional support to a subject in the form of water-soluble and fat-soluble nutrients. The present application provides formulations for administering important nutrients (e.g., DHA, ARA, amino acids such as arginine and glutamine, and other nutrients) in order to prevent the development of a nutritional deficiency, correct an existing nutritional deficiency, and/or promote healthy development in a subject.

Hereinafter, "emulsion" refers to a mixture of two or more immiscible liquids containing a dispersed phase and a continuous phase. In emulsions, a liquid, referred to as the dispersed phase, is dispersed into another liquid, referred to as the continuous phase, the bulk phase, or the aqueous component.

"surfactant" or "emulsifier" refers to a surface active substance that increases the stability of an emulsion. The surfactant is located at the interface between the dispersed phase of the emulsion and the aqueous phase. Surfactants can increase the stability of the emulsion so that once formed, the emulsion does not separate during years of storage.

By "preterm infant" is meant a subject born 37 weeks prior to gestational age. The phrase "premature infant" and the phrase "immature infant" are used interchangeably.

By "low birth weight infant" is meant an infant with a birth weight of less than 2500 grams (approximately 5 pounds, 8 ounces).

By "very low birth weight infant" is meant an infant with a birth weight of less than 1500 grams (approximately 3 pounds, 4 ounces).

"infant" refers to individuals ranging in age from birth to no more than about 1 year of age, including infants from 0 to about 12 months of reduced age. The term infant includes low birth weight infants, very low birth weight infants and premature infants.

All percentages, parts and ratios used herein are by weight of the total formulation, unless otherwise specified.

The nutritional formulations of the present application may also be substantially free of any optional or selected ingredients described herein, so long as the remaining nutritional formulation still contains all of the desired ingredients or characteristics described herein. In this context, unless otherwise indicated, the term "substantially free" means that the selected formulation contains less than a functional amount of the optional ingredient, typically less than 0.1% by weight, and also includes 0% by weight of such optional or selected ingredient.

All references to a single feature or limitation of the present application are to be understood as including the corresponding plural feature or limitation and vice versa unless the context clearly dictates otherwise or the reference explicitly implies otherwise.

All combinations of methods or steps described herein can be performed in any order, unless otherwise indicated herein or clearly contradicted by context.

The methods and formulations of the present application, including components thereof, can contain, consist of, or consist essentially of the essential elements and limitations of the invention described herein, as well as any additional or optional elements, components, or limitations described herein or otherwise useful in nutritional formulations.

The term "about" as used herein should be construed to refer to any two numerical values defined within any range. Reference to a range should be considered to provide support for any subset of the ranges.

The nutritional formulations of the present application can provide nutritional support and individualized nutrition to preterm infants, or any other patient with an unmet nutritional need. Thus, in some embodiments, the nutritional formulations are designed to meet a subject's individual (e.g., infant or preterm infant) specific nutritional needs in a stable unit dose liquid formulation that is standardized to a certain caloric content and/or as a concentrate to meet the subject's specific nutritional needs.

In addition, the present application provides nutritional formulations to combat malnutrition when providing nutrients to individuals that rely on parenteral or complete parenteral nutrition, thereby promoting healthy development of the subject. In fact, the nutritional formulation provides nutrients such as DHA that can promote, for example, visual and neurological development in infants.

The present application also provides methods of enteral administration of nutrients to subjects in need of administration of very small volumes of nutrients. Enteral administration as used herein includes nasogastric tube feeding, intragastric feeding, transpyloric administration, or any other method known in the art for introducing nutritional formulations directly into the digestive tract.

Thus, the present application is directed to the need for any population requiring small volume enteral nutritional support, such populations including, but not limited to, perioperative subjects, short bowel syndrome subjects, pediatric intensive care subjects, and/or any population of any age that cannot be fully orally fed or is receiving minimal enteral nutritional support or TPN. In addition, in some embodiments, the invention can provide nutritional support to a companion animal or a non-human primate.

In particular, the nutritional formulations of the present application may provide beneficial nutrients to an infant that are deficient due to, for example, premature or traumatic injury. Such nutrients include, but are not limited to, docosahexaenoic acid (DHA), arachidonic acid (ARA), arginine, glutamine, and any water-soluble or fat-soluble nutrient that may be provided in the nutritional formulations of the present application.

In at least one embodiment, the present application relates to a nutritional formulation that delivers a small volume of a set of specific nutrients to a subject. The resulting nutritional formulation may be commercially available and practically applicable in critical care settings, including but not limited to Neonatal Intensive Care Unit (NICU). In some embodiments, the nutritional formulations of the present application include an enteral nutritional delivery system whereby small and precise volumes of the nutritional formulation are introduced into the digestive tract of a subject. In some embodiments, the nutritional formulation is administered in a volumetric dose of about 1 mL. In other embodiments, the nutritional formulation may be supplied in a volume of up to about 1.5mL, or about 2 mL.

In some embodiments, the nutritional formulation supplies valuable nutrients to a preterm infant or infant in a small volume liquid dose of about 1 mL. Although preterm infants are often intolerant of complete enteral feeding due to illness, the nutritional formulations of the present application are designed to be administered as small volume nutritional supplements that can be directly administered to the infant through, for example, the nasogastric tube of all infants placed in the NICU. Thus, the nutritional formulation of the present application may be administered starting on the first day after delivery.

In addition, the nutritional formulation may be administered from 1 to 2 times per day or more as directed by a medical professional. Administration can begin immediately after birth and can continue as long as the subject has nutritional needs.

The formulation may contain a combination of fats to supply the desired mixture of fatty acids, or may contain a single fatty acid such as a long chain polyunsaturated fatty acid (LCPUFA) or a combination of LCPUFAs. LCPUFAs typically have a carbon chain length of at least 18 carbons. Suitable LCPUFAs include, but are not limited to, alpha-linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), arachidonic acid (ARA), and docosahexaenoic acid (DHA). In one embodiment, the formulation contains DHA. In some embodiments, the lipid component of the nutritional formulation primarily contains DHA. In one embodiment, both DHA and ARA are added to the nutritional formulation.

The nutritional formulation may contain omega-3 and/or omega-6 LCPUFAs. In some embodiments, the nutritional formulation may contain between about 5% w/w and about 20% w/w lipid. Additionally, in one embodiment, the nutritional formulation comprises a source of DHA comprising a mixture of DHASCO ® and/or fungal oil. In some embodiments, the nutritional formulation may contain between about 1% w/w and about 5% w/w DHA. In some embodiments, the DHASCO contains about 40% DHA and the fungal oil mixture contains about 15% DHA. The source of DHA can be any source known in the art.

In one embodiment, the nutritional formulation contains a source of ARA comprising ARASCO ® and/or a mixture of fungal oil. In some embodiments, the ARA component of the nutritional supplement contains about 30% of a fungal oil mixture. In some embodiments, the nutritional formulation may contain between about 1% w/w and about 5% w/w ARA. The ARA source may be any source known in the art.

Formulations known in the prior art tend to be physically unstable due to syneresis and the formation of non-dispersible precipitates. Instability is caused by high levels of protein, fat and minerals that known nutritional formulations must contain in order to provide adequate nutrition in a reasonable volume. Notably, acidification of conventional enteral formulations can also cause precipitation of proteins and phase separation. Often the precipitated nutrients cannot be returned to solution by shaking and do not provide the nutritional benefits needed to promote the health of the subject.

However, the nutritional formulation of the present application provides an improved enteral formulation that provides an acceptably small volume unit dose for preterm infants, contains valuable proteins, amino acids, and fatty acids, and has a shelf life of at least about 1 year due to its excellent physical stability. In addition, the present application provides new stabilization systems that generally prevent precipitation or separation of nutrients from enteral formulas and the preparation of nutritional formulations containing the stabilization systems.

The nutritional formulations of the present application may contain a stable emulsion that also contains a stabilizer, also known as an emulsifier. The emulsifier may comprise microcapsules, surfactants, emulsion stabilizers, or combinations thereof. In some embodiments, the lipid in the nutritional formulation is in the form of a stable emulsion. Emulsions can be stabilized by several mechanisms that can affect viscosity, density, particle size, and surface tension.

In some embodiments, the step of emulsifying may be by mechanical agitation, ultrasonic vibration, heating, or a combination thereof. Emulsification may be achieved using any emulsification method known in the art. In one embodiment, the emulsification may comprise homogenization. In some embodiments, multiple homogenization steps may be applied.

In some embodiments of the stable emulsion, the protein may act as a surfactant. Protein surfactants have the ability to diffuse at the lipid-water interface to reduce droplet coalescence. In fact, protein surfactants can lower the interfacial tension between two liquids, causing the two liquids to be miscible. The nutritional formulation may contain any emulsifier that is water soluble.

In one embodiment, the formulation contains an emulsion of LCPUFA stabilized by a protein matrix that includes alpha-lactalbumin. The emulsified LCPUFA may contain DHA. The alpha-lactalbumin acts as a stabiliser, in particular a surfactant. Additional surfactants, emulsion stabilizers, and microcapsules may be employed, but are not necessary to prepare the stable emulsified nutritional formulations of the present application.

The structure of alpha-lactalbumin confers its ability to move and spread at the water-lipid interface, thereby producing a thermodynamically stable emulsion. This structure also confers the ability to synergistically bind with itself at the water-lipid interface, thus creating a synergistic surface absorption, allowing for strong stable emulsion formation.

Some embodiments of the nutritional formulation, such as those optimized for preterm or severely ill infants, may mimic certain characteristics of human milk. In fact, the nutritional formulation may contain alpha-lactalbumin, which is the predominant whey protein in human milk. The addition of alpha-lactalbumin to preparations for premature infants can provide several physiological and nutritional benefits. Likewise, the addition of DHA, ARA and arginine, as well as glutamine, will provide physiological benefits to the infant.

The present application provides methods of using alpha-lactalbumin as a surfactant to stabilize an emulsion to reduce droplet coalescence and subsequent emulsion separation of the nutritional formulation. In some embodiments, the nutritional formulation contains between about 0.1% w/w and about 1.0% w/w alpha-lactalbumin.

The alpha-lactalbumin in the nutritional formulation may be highly purified alpha-lactalbumin. Highly purified alpha-lactalbumin comprises at least about 90% w/w alpha-lactalbumin, preferably at least about 95% w/w alpha-lactalbumin, even more preferably at least about 98% w/w alpha-lactalbumin. The use of highly purified alpha-lactalbumin to produce a stabilised emulsion system is unique and advantageous, particularly in the case of application to premature and severely diseased infants.

The addition of alpha-lactalbumin to the nutritional formulations herein may involve obtaining an aqueous dispersion of alpha-lactalbumin in the bulk phase (i.e. the aqueous component such as water) at a concentration ranging from about 5mg/L to about 30 mg/L. Furthermore, the source protein may have a concentration of greater than about 95% w/w and the concentration of alpha-lactalbumin is greater than about 90% w/w. In some embodiments, the nutritional formulation contains between about 0.1% w/w and about 1.0% w/w alpha-lactalbumin.

The purity of alpha-lactalbumin is important and it is an object of the present application to provide a small volume of nutrient delivery formulation. Therefore, the selection of the ingredients of the nutritional formulation must be directed to those nutrients that are most physiologically relevant. The maximally highly purified alpha-lactalbumin fraction available should be used for preparing the emulsion in order to minimize the possibility that increasing the amount of alpha-lactalbumin required to stabilise the emulsion may have a very adverse effect on the effective dose of physiologically relevant nutrients that may be contained in a small volume fraction or dose of the nutritional formulation.

Furthermore, the selection of highly purified alpha-lactalbumin increases the hypoallergenicity of the nutritional formulation. As the purity of the protein matrix decreases, the likelihood of containing a reactant, such as β -lactoglobulin, increases. The subject taking the presently described nutritional formulation may be a preterm infant with a very immature digestive tract or a severely ill patient. Thus, exposure to any allergen or impurity may exert pressure on the subject's immune response, any such reaction being undesirable. The purest protein available should therefore be used to avoid an unwanted immune response in the subject. The protein matrix used in the nutritional formulation may include a protein that has been previously treated or hydrolyzed. The protein matrix may be hydrolyzed by enzymatic hydrolysis, chemical disruption, physical-mechanical disruption, non-mechanical disruption, or a combination thereof.

The pH of the above-described dispersed phase can be adjusted to a level near the isoelectric point of about 4.2 to about 4.5 using an acidifying agent. Edible acids such as citric acid may be used as acidulants to adjust the pH of the nutritional formulation. Acidulants used in the nutritional formulations of the present application include, but are not limited to, citric acid and phosphoric acid.

The lipid phase (e.g., DHA) of the dispersion may be added to the dispersion at a concentration ranging from about 75 to about 300mg per 100mL, so as to provide the subject with a target of about 34mg of the lipid component per day. In some embodiments, the nutritional formulation contains between about 1% w/w and about 5% w/w DHA.

The aqueous component constituting the bulk phase of the emulsion may be any suitable material known in the art. In one embodiment, the bulk phase of the emulsion comprises water.

To obtain a stabilized emulsion, the emulsification process can be carried out using a single stage homogenizer having a flux rate of up to about 250mL/min, between about 5000 to about 15,000psi, and a temperature in the range of between about 2 ℃ and about 40 ℃ ± 2 ℃.

High pressure is applied to the dispersion to obtain homogenization. Sonication can be used to disperse the alpha-lactalbumin and bring it into the interface where the emulsion droplets are formed.

The emulsion obtained according to the above process contains oil/lipid droplets ranging from about 0.070 μm to about 1 μm in diameter.

Other nutrients and components, such as amino acids, vitamins and minerals, may be added to the phase or aqueous ingredients in the emulsion. It may be advantageous to add such other components directly to the emulsion by mixing after homogenization. In fact, the emulsion stabilized by alpha-lactalbumin allows the addition of other nutrients to the aqueous component without desorption, disruption or coalescence of the lipid droplets.

In addition, in some embodiments, the nutritional formulation comprising the emulsion is nutritionally complete, containing lipids, carbohydrates, proteins, vitamins, and minerals in appropriate types and amounts as the sole source of nutrition for the subject.

The formulation may also contain essential amino acids, such as arginine and/or glutamine. The amino acid may be provided in any form that can be ingested and absorbed. Therefore, arginyl-glutamine or alanyl-glutamine can be used as a dipeptide source of arginine and glutamine, rather than the individual amino acids arginine and glutamine, in order to improve the stability of the formulation, or due to the improved solubility and absorption capacity of the dimer over the monomer.

In some embodiments, the nutritional formulation contains glutamine-glutamine dipeptide, glycyl-glutamine dipeptide, N-acetyl-glutamine, or other water-stable glutamine analogs.

Arginine is an essential amino acid in infants. A decrease in plasma arginine levels may reflect respiratory distress syndrome, or may be associated with necrotic enteritis; however, the necrotic enteritis syndrome can be alleviated by arginine supplementation. Thus, the nutritional formulations of the present application may contain up to about 250mg/mL arginine. In some embodiments, the formulation contains less than about 225mg/mL arginine, and in further embodiments, the formulation contains less than about 216mg/mL arginine.

Further, in some embodiments, the nutritional formulation may contain between about 15% w/w and about 20% w/w arginine. In one embodiment, the nutritional formulation provides 500 mg/kg/day arginine to the subject.

Likewise, glutamine plays an important role in immune function, and is particularly beneficial to intestinal cells. Moreover, low birth weight infants receiving glutamine may have a reduced need for mechanical ventilation. Thus, the nutritional formulation may contain glutamine in a water-stable form, which may be supplied in the form of alanyl-glutamine dipeptide or arginyl-glutamine dipeptide. Alanyl-glutamine dipeptide may be preferred over arginyl-glutamine dipeptide due to its commercial availability and relatively efficient synthetic methods.

In one embodiment, it is beneficial to provide arginine and glutamine in the form of an arginyl-glutamine dipeptide that has excellent water solubility and bioavailability for humans and animals. In one form, the arginyl-glutamine dipeptide has an N-terminal amino acid, arginine, and a C-terminal amino acid, glutamine. Due to the improved stability, increased solubility and increased absorption of the dimer over the monomer, Arg-Gln is applied as a dipeptide, not as a separate amino acid.

In one embodiment of the present application, arginine, glutamine and/or arginyl-glutamine or alanyl-glutamine dipeptide can be used to prevent abnormal retinal vascular proliferation in infants or premature infants. The term "dipeptide" refers to at least arginyl-glutamine dipeptide and alanyl-glutamine dipeptide. Thus, in some embodiments, the nutritional formulation supports healthy visual development.

In one embodiment, the subject is administered a combination of arginine and glutamine or an arginyl-glutamine dipeptide in an amount effective to prevent abnormal vascular proliferation. The amount can be from about 0.001 to about 10,000 mg/kg-day (where unit mg/kg-day refers to milligrams of a combination of arginine and glutamine or the Arg-Gln dipeptide in approximately equimolar amounts per kilogram of body weight of the subject per day).

The nutritional formulation may contain less than about 400mg/mL arginyl-glutamine, in some embodiments up to 375mg/mL arginyl-glutamine, and in other embodiments up to 387mg/mL arginyl-glutamine. In certain embodiments, the nutritional formulation may contain between about 100 and about 400mg/mL arginyl-glutamine.

The nutritional formulation may contain less than about 300mg/mL alanyl-glutamine, in some embodiments up to about 280mg/mL alanyl-glutamine, and in other embodiments 269 mg/mL.

In some embodiments, the nutritional formulation contains between about 8% w/w and about 12% w/w alanylglutamine. In one embodiment, the nutritional formulation provides 300 mg/kg/day alanylglutamine to the subject.

In order to minimize any loss of this valuable nutrient component, it is preferred to add nutrients having high nutritional value, such as arginine and alanyl-glutamine dipeptide, after homogenization.

Furthermore, in some embodiments, the nutritional formulation contains both DHA and Arg-Gln. Embodiments of the nutritional formulation containing both DHA and Arg-Gln may promote healthy development of vision and nerves in infants.

For example, as shown in figure 1, administration of Arg-Gln dipeptide in conjunction with DHA may exhibit a synergistic effect that significantly reduces the formation of retinal neovascularization in infants. Figure 1 shows the effect of administration of the compound in an OIR mouse model, showing a summary of the results of an analysis of the level of pre-retinal neovascularization in an OIR mouse model.

Tube feeding of Arg-Gln dipeptide showed a dose-dependent reduction in the formation of pre-retinal neovascularization, relative to vehicle control, which reduced pre-retinal neovascularization to 39 + -6% (P <0.05), similar to intraperitoneal injection of Arg-Gln dipeptide at a dose of 5g/kg body weight/day. Gavage of DHA at a dose of 2.5g/kg body weight/day also reduced the formation of omentum neovascularisation to 49 + -4% (P < 0.05). Gavage of Arg-Gln dipeptide (5g/kg body weight/day) and DHA (2.5g/kg body weight/day) showed a synergistic effect of reducing the formation of the anterior retinal neovascularization to 31 + -4% (P < 0.05).

Together with the amino acid or dipeptide, the composition of the present application may contain additional nitrogen sources (i.e., other amino acids and/or proteins).

The nutritional formulations of the present application may also contain flavoring agents, flavor enhancers, sweeteners, colors, vitamins, minerals, therapeutic ingredients, functional food ingredients, processing ingredients, or combinations thereof.

The nutritional formulation may also optionally include any number of proteins, peptides, amino acids, fatty acids, probiotics and/or their metabolic byproducts, prebiotics, carbohydrates, and any other nutrients or other compounds that may provide a number of nutritional and physiological benefits to a subject. The carbohydrates used in the nutritional formulation may be any digestible carbohydrates, such as glucose, fructose, sucrose, maltose, maltodextrin, corn syrup solids, or mixtures thereof, depending on the method of use. Due to the ease of digestion, hydrolysed carbohydrates are preferred.

In certain embodiments, the nutritional formulations of the present application further comprise at least one prebiotic. In this embodiment, any prebiotic known in the art may be added. In a particular embodiment, the prebiotic may be selected from the group consisting of fructo-oligosaccharides, gluco-oligosaccharides, galacto-oligosaccharides, isomalto-oligosaccharides, xylo-oligosaccharides and lactulose.

The present application also provides methods of making nutritional formulations containing the emulsions. As previously described, the method includes emulsifying the lipid component with a protein surfactant to form a stable product. Accordingly, the present application provides methods of minimizing degradation of nutrients (including LCPUFAs) in stable formulations (e.g., nutritional formulations).

The nutritional formulations of the present application may be commercially packaged so as to be directly connectable to enteral nutrition devices including, but not limited to, nasogastric intubation, percutaneous endoscopic gastrectomy, percutaneous endoscopic jejunostomy, transpyloric intubation, and the like. Such a design is convenient for ensuring complete supply of the package contents, minimizing the risk of contamination and improving compliance. Additionally, in certain embodiments, the nutritional formulation may be packaged in a single dose supply package of about a total volume of 1mL, about a total volume of 1.5mL, or about a total volume of 2 mL.

The nutritional formulation can be directly administered into the intestinal tract of a subject. In some embodiments, the nutritional formulation is placed directly into the intestinal tract. In some embodiments, the formulation can be prepared for enteral use or administration under the supervision of a physician, and can be used for specific dietary management of a disease or condition for which unique nutritional needs are established by medical evaluation based on known scientific principles.

The nutritional formulations of the present application are not limited to formulations containing the nutrients specifically enumerated herein. Any nutrients may be administered as part of the formulation in order to meet the nutritional needs of the subject and/or to optimize the nutritional status of the subject.

In some embodiments, the nutritional formulation may be administered to preterm infants from birth to at least about 3 months of corrected age. In further embodiments, the nutritional formulation may be administered to the subject as long as necessary to correct the nutritional deficiency. In a further embodiment, the nutritional formulation may be administered to an infant from birth to at least about 1 year of corrected age.

The nutritional formulations of the present application may be standardized to a particular caloric value, may be provided as a ready-to-use product, or may be provided in a concentrated form.

In one embodiment, the present application provides a method of preparing a nutritional formulation comprising the steps of: (i) preparing an aqueous dispersion of about 1 to about 30mg/L of a protein matrix in a bulk phase, wherein the protein matrix contains at least 90% w/w of alpha-lactalbumin, (ii) adjusting the pH of the dispersion to between about 4.2 and about 4.5, (iii) adding between about 75 and about 300mg/100mL of a lipid component, and (iv) emulsifying the lipid component to produce droplets of the lipid component having a diameter in the range of 0.070 μm to about 1 μm.

In another embodiment, the present application provides a nutritional supplement for enteral administration comprising a nutritional fatty acid emulsion in an aqueous ingredient containing additional nutrients to meet the nutritional needs of the infant.

In one embodiment, the nutritional formulation of the present application contains DHA, ARA, arginine, and glutamine, wherein arginine and glutamine can be provided in the form of oligopeptides.

By addressing and correcting the nutritional deficiencies of currently available products, the nutritional formulations and methods of the present application provide significant benefits over the prior art. In addition, the nutritional formulation of the present invention provides valuable nutrients to preterm infants who are unacceptable when relying on existing sources of TPN.

The following examples are provided for illustration of the presently disclosed invention and should not be construed as limiting thereof.

Examples

Table 1 gives 4 examples of liquid nutritional formulations of the present application. The concentration of each ingredient is listed in the table and is in grams/kg/day. In addition, each of the formulations in table 1 was normalized to be equimolar with arginyl-glutamine. Embodiments of the nutritional formulations described in table 1 are suitable for administration to an animal, such as a rodent or piglet model.

DHASCO refers to a fertilizer made of unicellular algae Crypthecodinium cohnii (CCrypthecodinium cohnii) Mixed oil of extracted oil and high oleic sunflower oil. The obtained mixed oil contains DHA about 40-45 wt% of the product. DHASCO is commercially available from Martek Biosciences Corporation.

Table 2 provides additional examples of liquid nutritional formulations of the present application. Table 2 provides examples of nutritional formulations suitable for use in human infants. The concentration of each component is listed in the table and is given in% w/w.

ARASCO refers to single cell fungus Mortierella alpina (ARASCOMortierella alpine) The mixture of extracted oil and HOSO contains ARA 38-33 wt%. ARASCO contains no detectable levels of eicosapentaenoic acid (EPA) or other LCPUFAs. The DHASCO and ARASCO are absorbed by healthy infants in the same way as the edible triglycerides.

Table 3 gives an embodiment of the nutritional formulation, which is optimized for small volume administration to human infants. The embodiment of table 3 may be administered to an infant consuming about 100 kcal/day weighing about 1kg, for example, twice a day at a dose of about 1.5 mL. The concentration of each component is given in the% w/w range.

More particularly, the nutritional formulation described in table 3 may contain about 24.3% arginine, about 14.6% glutamine, about 13.8% lipid component, and about 0.69% alpha-lactalbumin. In another embodiment, the nutritional formulation described in table 3 may contain about 0.250g of arginine, about 0.150g of alanylglutamine, about 0.0955g of DHASCO, about 0.0469g of ARASCO, and about 0.007g of alpha-lactalbumin.

In another embodiment, the nutritional formulation may be adapted for supply to a human infant weighing about 1kg, wherein said infant receives about 1mL of the nutritional formulation per day for 2 doses and the infant receives approximately 150 kcal/day. In such embodiments, the nutritional formulation may contain about 0.250g of arginine, about 0.150g of alanylglutamine, about 0.0955g of DHASCO, about 0.0469g of ARASCO, and about 0.007g of alpha-lactalbumin.

All references cited in this specification, including but not limited to all papers, publications, patents, patent applications, statements, texts, reports, manuscripts, manuals, books, internet postings, journal articles, periodicals, and the like, are hereby incorporated by reference in their entirety. The discussion of the references herein is intended merely to summarize the assertions made by the authors and no admission is made that any reference constitutes prior art. Applicants reserve the right to challenge the accuracy and pertinence of the cited references.

Although specific terms, devices, and methods have been used in the description of the preferred embodiments of the application, such descriptions are for illustrative purposes only. The language used is intended to be descriptive, not limiting. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or scope of the present application, which is set forth in the following claims. Additionally, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. For example, while the preparation of commercially sterile liquid nutritional supplements obtained according to those methods is listed, other applications are contemplated. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.

Claims (20)

1. A nutritional formulation comprising:

an emulsion comprising docosahexaenoic acid, wherein the emulsion is dispersed in an aqueous component comprising at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine, and alanyl-glutamine; and

an emulsifier comprising highly purified alpha-lactalbumin.

2. The liquid nutritional formulation of claim 1, wherein the emulsifier comprises at least about 95% w/w alpha-lactalbumin.

3. The liquid nutritional formulation of claim 1, wherein the emulsifier comprises at least about 98% w/w alpha-lactalbumin.

4. The liquid nutritional formulation of claim 1, further comprising at least one prebiotic.

5. The liquid nutritional formulation of claim 1, further comprising vitamins and minerals.

6. The liquid nutritional formulation of claim 1, further comprising at least one omega-6 fatty acid.

7. The liquid nutritional formulation of claim 1, further comprising arachidonic acid.

8. A method of providing nutritional support to a subject, the method comprising administering to the subject a nutritional formulation comprising:

an emulsion comprising docosahexaenoic acid, wherein the emulsion is dispersed in an aqueous component comprising at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine, and alanyl-glutamine; and

an emulsifier comprising highly purified alpha-lactalbumin.

9. The liquid nutritional formulation of claim 8, wherein the emulsifier comprises at least about 95% w/w alpha-lactalbumin.

10. The liquid nutritional formulation of claim 8, wherein the emulsifier comprises at least about 98% w/w alpha-lactalbumin.

11. The liquid nutritional formulation of claim 8, further comprising at least one prebiotic.

12. The liquid nutritional formulation of claim 8, further comprising vitamins and minerals.

13. The liquid nutritional formulation of claim 8, further comprising at least one omega-6 fatty acid.

14. The liquid nutritional formulation of claim 8, further comprising arachidonic acid.

15. A method of providing nutritional support to a preterm infant, wherein the method comprises enterally administering to the preterm infant a nutritional formulation comprising:

an emulsion comprising docosahexaenoic acid, wherein the emulsion is dispersed in an aqueous component comprising arachidonic acid and at least one amino acid component selected from the group consisting of arginine, arginyl-glutamine, and alanyl-glutamine; and

an emulsifier comprising at least about 95% w/w alpha-lactalbumin.

16. The liquid nutritional formulation of claim 15, wherein the emulsifier comprises at least about 98% w/w alpha-lactalbumin.

17. The liquid nutritional formulation of claim 15, further comprising at least one prebiotic.

18. The liquid nutritional formulation of claim 15, further comprising vitamins and minerals.

19. The liquid nutritional formulation of claim 15, further comprising an alanyl glutamine dipeptide.

20. The liquid nutritional formulation of claim 15, further comprising arginyl glutamine dipeptide.