A SUNSCREEN FORMULATION
20210361548 · 2021-11-25
Inventors
Cpc classification
A61Q17/04
HUMAN NECESSITIES
A61K2800/805
HUMAN NECESSITIES
A61K8/84
HUMAN NECESSITIES
International classification
A61K8/84
HUMAN NECESSITIES
Abstract
The present invention relates to the synthesis of new classes of sunscreen agents, the usage of such sunscreen agents in sunscreen formulations aiming at reduction of sunscreen agents' skin penetration, and a formulation technology using existing sunscreen agents aiming at reduction of sunscreen agents' skin penetration, therefore improving the bio-safety of the sunscreen products.
Claims
1. A sunscreen formulation comprising: (1) an ionic complex that is formed between a compound A and an excipient B; and (2) an aqueous based carrier for topical administration, wherein the compound A is a sunscreen compound in enol form or with an active acidic proton or derivatized with —[CH.sub.2].sub.nCOOH or —[CH.sub.2].sub.nNH.sub.2, n=0-18; the excipient B contains an amine functional group when the sunscreen compound is in enol form or with an active acidic proton or derivatized with —[CH.sub.2].sub.nCOOH, and contains a carboxyl functional group when the sunscreen compound A is derivatized with —[CH.sub.2].sub.nNH.sub.2; and the formulation is substantially free of the compound A in a free form.
2. The formulation of claim 1 comprising less than 20% molar equivalent of the compound A in free form relative to the molar amount of the ionic complex.
3. The formulation of claim 1 being free of a compound that is substantially detrimental to formation or existence of the ionic complex or the stability of the formulation.
4. The formulation of claim 3 wherein the compound that is substantially detrimental to formation or existence of the ionic complex or the stability of the formulation is another ionic compound that has not been recited in claim 1.
5. The formulation of claim 3 wherein the compound that is substantially detrimental to formation or existence of the ionic complex or the stability of the formulation is an ionic surfactant.
6. The formulation of claim 1 wherein the sunscreen compound to be derivatized with [CH.sub.2].sub.nCOOH is selected from the group consisting of avobenzone, cinoxate, dioxybenzone, homosalate, octocrylene, octyl methoxycinnamate, octyl salicylate, oxybenzone, and combinations thereof, and the derivatized sunscreen compound has the following structure: ##STR00028##
7. The formulation of claim 1 wherein the sunscreen compound to be derivatized with —[CH.sub.2].sub.nNH.sub.2 is selected from the group consisting of avobenzone, cinoxate, dioxybenzone, homosalate, octocrylene, octyl methoxycinnamate, octyl salicylate, oxybenzone, and combinations thereof, and the derivatized sunscreen compound has the following structure: ##STR00029##
8. The formulation of claim 1 wherein the excipient B that contains the amine functional group is selected from the group consisting of spermidine, spermine, tris-(2-aminoethyl)amine, 1,1,1-tris(aminomethyl)ethane, cyclen, polyvinylamine, polyallylamine, polyethyleneimine, chitosan, and combinations thereof.
9. The formulation of claim 1 wherein the excipient B that contains the carboxyl function group is selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, citric acid, isocitric acid, propane-1,2,3-tricarboxylic acid, carboxymethyl cellulose, polyacrylic acid, hyaluronic acid, and combinations thereof.
10. The formulation of claim 1 wherein the sunscreen compound in enol form is avobenzone.
11. The formulation of claim 1 wherein the sunscreen compound with the active acidic proton is selected from the group consisting of oxybenzone, diethylamino hydroxybenzoyl hexyl benzoate, homosalate, dioxybenzone, 2-ethylhexyl salicylate, sulisobenzone, and combinations thereof.
12. The formulation of claim 1 wherein the aqueous based carrier is selected from the group consisting of aqueous based chitosan, aqueous based hyaluronic acid, aqueous based PEG200, aqueous based PEG400, aqueous based PEG1500, and combinations thereof.
13. A method for protecting skin from ultraviolet radiation comprising applying the formulation of claim 1 to the skin in need thereof.
14. A method of making the formulation of claim 1 comprising: dissolving the compound A in the carrier, reacting with the excipient B, and blending to form the formulation at a temperature range from 20° C. to 50° C.
15. The method of claim 14 comprising, prior to the step of blending, a step of making the compound A by derivatizing the sunscreen compound with —[CH.sub.2].sub.nCOOH or —[CH.sub.2].sub.nNH.sub.2, n=0-18.
16. (4-aminomethoxy-2-hydroxy-phenyl) phenyl-methanone of the following formula: ##STR00030##
17. The formulation of claim 1 wherein the formulation is homogeneously transparent.
18. The formulation of claim 1 wherein the formulation is in form of an ointment or a viscus solution.
19. The formulation of claim 6 wherein the derivatized sunscreen compound is (4-benzoyl-3-hydroxy-phenoxy)-acetic acid of the following formula: ##STR00031##
20. The formulation of claim 7 wherein the derivatized sunscreen compound is (4-benzoyl-3-hydroxy-phenoxy)-acetic acid of the following formula: ##STR00032##
Description
BRIEF DESCRIPTION OF THE DRAWING
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0036] The following embodiments are provided to illustrate, but not to limit the instant invention.
[0037] New organic sunscreen agents with specifically designed functions for formulation purposes were synthesized.
[0038] A formulation scheme of using sunscreen agents containing a carboxy group coupled with simple organic compounds, oligomers, or macromolecules which contains amine groups was developed. Such combination is to result in interaction between a carboxy group of a sunscreen agent and an amine group of an excipient molecule to reduce/eliminate skin penetration of the sun screen agent.
[0039] A formulation scheme of using sunscreen agents containing amine groups coupled with simple organic compounds, oligomers, or macromolecules containing carboxy group was developed. The ionic interaction between the amino groups of the sunscreen agent and the carboxy groups of the excipient molecules will reduce, minimize, or eliminate skin penetration of sunscreen agents.
[0040] A formulation scheme of utilizing amino-group-containing simple organic compounds, oligomers, or macromolecules to interact with enol form of sunscreen agent (avobenzone) or with the active acidic proton of sunscreen agents (oxybenzone, diethylamino hydroxybenzoyl hexyl benzoate, homosalate, dioxybenzone, 2-ethylhexyl salicylate, sulisobenzone), was developed to generate ionic interaction between the amino-group-containing simple organic compounds, oligomers, or macromolecules and sunscreen agents. Such combination is to minimize, reduce, or eliminate skin penetration of sunscreen agents by promoting the interaction between the sunscreen agents and NH.sub.2 groups of the excipient.
[0041] The present inventor has made intensive research to develop new active sunscreen agents bearing specifically designed function groups and to develop formulation scheme which will reduce skin penetration of sunscreen agents or at best eliminate the skin penetration of sunscreen agents for the ultimate purposes of enhancing the bio-safety of sunscreen products.
[0042] Accordingly, it is an objective of this invention to provide a synthesis of sunscreen agents which bears a carboxyl function group specifically designed for formulation purpose.
[0043] It is another objective of this invention to provide a synthesis of sunscreen agents which bears an amine function group specifically designed for formulation purpose.
[0044] In one aspect of the present invention there is provided a formulation scheme using the enol form or an active acidic proton of the sunscreen agents chemically interacting with NH.sub.2 groups of simple organic compounds, oligomers, or macromolecules to reduce skin penetration of sunscreen agents or stop the skin penetration of sunscreen agents for the ultimate purposes of enhancing the bio-safety of sunscreen products.
[0045] In another aspect of the present invention, there is provided a formulation scheme using sunscreen agents bearing carboxyl function groups and excipients consisting of amine groups to reduce skin penetration of sunscreen agents or stop the skin penetration of sunscreen agents for the ultimate purposes of enhancing the bio-safety of sunscreen products.
[0046] In still another aspect of the present invention, there is provided a formulation scheme using sunscreen agents bearing amine function groups and the excipients consisting of carboxyl groups to reduce skin penetration of sunscreen agents or stop the skin penetration of sunscreen agents for the ultimate purposes of enhancing the bio-safety of sunscreen products.
EXAMPLES
[0047] The invention is illustrated herein by the experiments described by the following examples, which should not be considered as limiting. Those skilled in the art will understand that this invention may be embodied in many different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will fully convey the invention to those skilled in the art. Many modifications and other embodiments of the invention will come to mind in one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing description. Although specific terms are employed, they are used as in the art unless otherwise indicated.
Example 1
Synthesis of Sunscreen Agent (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid
Synthesis scheme of (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid
[0048] ##STR00006##
Synthesis of Intermediate 3
[0049]
TABLE-US-00001
[0050] To a nitrogen-filled three-necked-flask 1,3-dihydroxy-benzene (10 g, 0.09 mol) and chlorobenzene (75 mL) were charged. Aluminum chloride (14.53 g, 0.11 mol) was added while stirring. Benzyl chloride was added to the above mixture drop wisely. After completing the addition, the temperature of the content was raised to 90° C. while stirring. The agitation was stopped when the compound 1,3-dihydroxy-benzene was used up with TLC (PE:EA=2:1)
[0051] When the temperature dropped to 50° C., dichloromethane (500 mL) and 1N sodium hydroxide (200 mL) were added. The mixture was stirred for 5 min. After settling, separate organic phase from aqueous phase. To the aqueous phase was added 1N hydrochloric acid until the pH reached pH=4. A huge amount of solids were precipitated. The solid was vacuum-filtered and washed with water until the filtrate is neutral. Drying in an oven, a yellowish solid product 2,4-dihydroxybenzophenone was obtained (18.90 g, 97.1%).
Synthesis of Intermediate 4
[0052]
TABLE-US-00002
[0053] To a three-necked-flask containing 2,4-dihydroxy-benzophenone (2.14 g, 0.01 mol) and acetone (100 mL) were charged tert-butyl 2′-bromo-acetate (1.95 g, 0.01 mol), potassium carbonate (5.49 g, 0.03 mol), potassium iodide (1.66 g, 0.01 mol), and 18-crown-6 (2.64 g, 0.01 mol) while stirring. The mixture was stirred and heated until re-fluxing. Stopped the reaction when all 1,3-dihydroxy-benzophenone was consumed monitored with TLC (PE:EA=2:1). Let the temperature drop to ambient temperature. Filter under vacuum, the solids were washed with acetone. For filtrate the solvent was removed under vacuum completely. Via silicon column (PE:EA=20:1) Compound (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid tert-butyl ester white solid was obtained (2.23 g, yield 72.9%)
Synthesis of (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid
[0054]
TABLE-US-00003
[0055] To a flask containing (4-benzoyl-3-hydroxy-phenoxy)-acetic acid tert-butyl ester (2 g, 6.09 mmol) and dichloromethane was added trifluoroacetic acid (10 mL, 130.6 mmol) while stirring. After Stirring for 3 hours (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid tert-butyl ester disappeared based on TLC (PE:EA=3:1). Under vacuum trifluoroacetic acid was removed. The concentrate was dissolved in dichloromethane (150 mL). The organic phase was washed with 1N sodium hydroxide solution (50 mL). The aqueous phase was yellow in color. Under agitation 1N hydrochloric acid was added to the aqueous phase resulting in the formation of white precipitate and the final pH=7. Under vacuum filtrate and the solid was washed with water. Drying (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid (1.34 g, 80.7%)
Example 2
Synthesis of Sunscreen Agent (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone
Synthesis scheme of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone
[0056] ##STR00014##
Synthesis of Intermediate 3
[0057]
TABLE-US-00004
[0058] To a nitrogen-filled three-necked-flask 1,3-dihydroxy-benzene (10 g, 0.09 mol) and chlorobenzene (75 mL) were charged. Aluminum chloride (14.53 g, 0.11 mol) was added while stirring. Benzyl chloride was added to the above mixture drop wisely. After completing the addition, the temperature of the content was raised to 90° C. while stirring. The agitation was stopped when the compound 1,3-dihydroxy-benzene was used up monitored with TLC (PE:EA=2:1)
[0059] When the temperature was dropped to 50° C., dichloromethane (500 mL) and 1N sodium hydroxide (200 mL) were added. The mixture was stirred for 5 min. After settling, separate organic phase from aqueous phase. To the aqueous phase was added 1N hydrochloric acid until the pH reached pH=4. A huge amount of solids were precipitated. The solid was filtered under vacuum and washed with water until the filtrate is neutral. Drying in an oven, a yellowish solid product 2,4-dihydroxybenzophenone was obtained (18.90 g, 97.1%).
Synthesis of Intermediate 5
[0060]
TABLE-US-00005
[0061] To a three-necked-flask containing 2,4-dihydroxy-benzophenone (2.14 g, 0.01 mol) and DMF (30 mL) were charged compound 2-Bromomethyl-isoindole-1.3-dione (2.40 g, 0.01 mol) and potassium carbonate (5.49 g, 0.03 mol) while stirring. The mixture was stirred and heated until refluxing. Stop the reaction when all 2,4-dihydroxy-benzophenone was used up monitored with TLC (PE:EA=2:1). The mixture was cooled down to room temperature. Filter under vacuum, the solids were washed with acetone. For filtrate the solvent was removed under vacuum completely. Via silicon column (PE:EA=20:1) Intermediate 5 was obtained as colorless solid (3.06 g, yield 81.9%)
Synthesis of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone
[0062]
TABLE-US-00006
[0063] To a 100 mL flask containing intermediate 5 (2 g, 5.35 mmol) and ethanol (10 mL) was added hydrazine (0.6 mL, 5.35×2 mmol) while stirring. The mixture was stirred for 3 hours at the temperature of re-fluxing and compound 5 disappeared based on TLC (PE:EA=2:1). Under vacuum ethanol was removed. The concentrate was dissolved in dichloromethane (50 mL). The organic phase was washed with saturated brine solution (20 mL). After separating the aqueous phase, the organic phase was dried over anhydrous sodium sulfate. The concentrated solution was subjected to silicate column purification. Yellowish solid of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone (0.78 g, yield 59.8%) was obtained.
Example 3
Benzoic Acid Formulation
Benzoic Acid Formulation Composition
[0064]
TABLE-US-00007 Benzoic Acid Chitosan Glycerol Water 260.84 mg 0.51 g 1.09 g 15.39 g
[0065] Add benzoic acid, chitosan polymer, and water to a beaker. Stir for 2 hours a solution was obtained. Add glycerol 1.09 g and mix thoroughly. Evaporate water at ambient temperature until reaching equilibrium. A transparent ointment (7.21 g) was obtained. Benzoic acid content is 3.6%.
[0066] Formulation Chemistry
[0067] Chitosan polymer contains —NH.sub.2 amine groups. The N % is 8.695%. When mixed with benzoic acid, —NH.sub.2 amine groups will react with benzoic acid to form benzoic anion and ammonium cation. Due to the ionic interaction between the chitosan and benzoic acid and the bulkiness of chitosan polymer the skin penetration of benzoic acid will be either dramatically reduced or eliminated.
##STR00022##
[0068] Benzoic Acid Control Formulation
[0069] For the purpose of comparison, a benzoic acid control formulation was prepared. Lack of the above-mentioned ionic interaction between benzoic acid and excipient matrix is the base as a control standard. The composition is listed in the following table.
Control Formulation Composition for Benzoic Acid Formulation
[0070]
TABLE-US-00008 Benzoic Acid PEG 400 PEG 1500 1.01 g 5.00 g 4.00 g
[0071] Weigh each component, benzoic acid, PEG 400 and PEG 1500, into a beaker. The mixture was heated in a 35° C. oven and was mixed thoroughly until a clear viscus solution was obtained. Cooling to room temperature yielded an ointment.
[0072] Mice Test Procedures: [0073] 1. Mice preparation and blood sample taking: 12 mice were fed with adequate food and water for 3 days. 12 hours before the test the food was removed and only water was given. The 12 mice were randomly divided into two groups. Two hours before the test the mice were subjected to anesthesia and the hair on the back (1.0-1.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0074] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0075] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0076] 4. HPLC analysis: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; mobile phase: MeOH:0.1% H.sub.3PO.sub.4=45:55; Flow rate: 1.0 mL/min.; Wavelength: 228 nm; Injection volume: 10 μL
Example 4
4-Methoxy-benzylamine Formulation
4-Methoxy-benzylamine Formulation Composition
[0077]
TABLE-US-00009 4-Methoxy-benzylamine Hyaluronic acid PEG 400 Water 0.50 g 1.71 g 2.00 g 4.72
[0078] Mix 4-methoxy-benzylamine (0.50 g) with PEG 400 (1.01 g). Add the mixture to the hyaluronic acid water solution (7.5%) while stirring. Evaporate water in an oven at 40° C. Add PEG 400 (0.99 g) to the mixture. Evaporate water in an oven at 40° C. until reaching equilibrium. An ointment (8.93 g) was obtained. The content of 4-Methoxy-benzylamine is 5.5%.
[0079] Formulation Chemistry
[0080] Hyaluronic acid is a polysaccharide polymer with carboxyl groups. The molar % of carboxyl group is 50.0%. When mixed with 4-methoxy-benzylamine, —NH.sub.2 amine groups will react with carboxyl groups to form carboxyl anion and ammonium cation. Due to the ionic interaction between the hyaluronic polymer and 4-methoxy-benzylamine, and the bulkiness of hyaluronic polymer, the skin penetration of 4-methoxy-benzylamine through into blood circulation system will be either dramatically reduced or completely eliminated.
Formulation Scheme of 4-Methoxy-benzylamine-/Hyaluronic Acid
[0081] ##STR00023##
4-Methoxy-benzylamine Control Formulation
[0082] For the purpose of comparison, a 4-methoxy-benzylamine control formulation was prepared. Lack of the above-mentioned ionic interaction between 4-methoxy-benzylamine and the excipient matrix is the base as a control standard. The composition is listed in the following table.
4-Methoxy-benzylamine Control Formulation Composition
[0083]
TABLE-US-00010 4-methoxy-benzylamine PEG 400 PEG 1500 0.50 g 5.56 g 3.87 g
[0084] Weigh PEG 400 and PEG 1500 into a beaker. The beaker was placed in a 35° C. oven. Mix until a clear solution was obtained. Weigh 4-methoxy-benzylamine into the container containing PEG 400 and PEG 1500. Mix thoroughly. A clear ointment was obtained at ambient temperature.
[0085] Mice Test Procedures: [0086] 1. Mice preparation and blood sample taking: 12 mice were fed with adequate food and water for 3 days. 12 hours before the test the food was removed and only water was given. The 12 mice were randomly divided into two groups. Two hours before the test the mice were subjected to anesthesia and the hair on the back (1.0-1.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0087] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0088] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0089] 4. HPLC analysis: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; mobile phase: ACN:H.sub.2O=60:40; Flow rate: 1.0 mL/min.; Wavelength: 254 nm; Injection volume: 20 μL;
Example 5
(4-Benzoyl-3-hydroxy-phenoxy)-acetic Acid Formulation
(4-Benzoyl-3-hydroxy-phenoxy)-acetic Acid Formulation Composition
[0090]
TABLE-US-00011 (4-Benzoyl-3-hydroxy- phenoxy)-acetic acid Polyethyleneimine PEG 400 PEG 1500 110.85 mg 261.97 mg 262.55 mg 235.44 mg
[0091] Dissolve polyethyleneimine (261.97 mg) in water (688.45 mg). Mix (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid (110.85 mg) with polyethyleneimine water solution prepared above. Add PEG 400 and PEG 1500 to the mixture while mixing. Raise temperature to 35° C. and keep mixing until a clear yellowish ointment (1.07 g) was obtained. The content of (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid is 10.36%.
[0092] Formulation Chemistry
[0093] (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid contains carboxyl group. When mixed with polyethyleneimine, —NH.sub.2 amine groups will react with carboxyl groups to form carboxyl anion and ammonium cation. Due to the ionic interaction and the formation of polyethyleneiminium multiple carbonate, (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid moieties were locked in the matrix. The diffusion of the active UV ray blocking agent through skin into blood circulation system will be either dramatically reduced or completely eliminated. PGP-6
Formulation Scheme of (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid/Polyethyleneimine
[0094] ##STR00024##
(4-Benzoyl-3-hydroxy-phenoxy)-acetic Acid Control Formulation
[0095] For the purpose of comparison, 2-Hydroxy-4-methoxybenzophenone (oxybenzophenone) was chosen to be the standard for (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid. Lack of above-mentioned interaction between the active UV ray blocking agent and the excipient matrix is the base as a control standard. The composition is listed in the following table.
2-Hydroxy-4-methoxybenzophenone Control Formulation Composition
[0096]
TABLE-US-00012 2-Hydroxy-4-methoxybenzophenone PEG 400 PEG 1500 207.20 mg 1001.80 mg 754.04 mg
[0097] Weigh PEG 400 and PEG 1500 into a beaker. The beaker was placed in a 35° C. oven. Mix until a clear solution was obtained. Weigh 2-Hydroxy-4-methoxybenzophenone into the container containing PEG 400 and PEG 1500. Mix thoroughly. A clear ointment was obtained.
[0098] Mice Test Procedures: [0099] 1. Mice preparation and blood sample taking: Twenty mice were fed with adequate food and water for 3 days. Twelve hours before the test the food was removed and only water was given. The 20 mice were randomly divided into two groups. Two hours before the test the mice were subjected to anesthesia and the hair on the back (2.0-2.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0100] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0101] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0102] 4. HPLC analysis: [0103] (4-Benzoyl-3-hydroxy-phenoxy)-acetic acid: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; mobile phase: [0104] MeOH:0.14% H.sub.3PO.sub.4=65:35; Flow rate: 1.0 mL/min.; Wavelength: 290 nm; Injection volume: 20 μL;
[0105] 2-Hydroxy-4-methoxybenzophenone: Column: C18 RP column (250×4.6 mm, 5 m); column temperature: 25° C.; Mobile phase: MeOH:H.sub.2O=80:20; Flow rate: 1.0 mL/min.; Wavelength: 290 nm; Injection volume: 20 μL;
Example 6
(4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone Formulation
(4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone Formulation Composition
[0106]
TABLE-US-00013 (4-Aminomethoxy-2- hydroxy-phenyl)-phenyl- methanone Glutaric acid PEG 200 PEG 1500 112.22 mg 31.35 mg 542.07 mg 388.21 mg
[0107] Mix PEG 200 (542.07 mg) and PEG 1500 (388.21 mg) while heating gently until a homogenous clear solution obtained. Dissolve glutaric acid (31.35 mg) in PEG 200/PEG 1500 solution (388.27 mg). Dissolve (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone (112.22 mg) in PEG 200/PEG 1500 solution (542.01 mg) prepared above. Mixing the two solutions yielded a clear yellowish ointment (1.07 g). The content of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone is 10.5%.
[0108] Formulation Chemistry
[0109] (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone contains —NH.sub.2 amino groups. When mixed with glutaric acid, NH.sub.2 amine groups of the active sun screen agent will react with carboxyl groups to form carboxyl anion and ammonium cation. Due to the ionic interaction and the formation of glutaric di-carbonate, the diffusion of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone moieties, the active UV ray blocking agent, through skin into blood circulation system will be either dramatically reduced or completely eliminated.
Formulation Scheme of (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone/Glutaric Acid
[0110] ##STR00025##
(4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone Control Formulation
[0111] For the purpose of comparison, 2-Hydroxy-4-methoxybenzophenone was selected as standard. Lack of above-mentioned interaction between the active UV ray blocking agent and the excipient matrix fulfil the purpose of a control standard. The composition is listed in the following table.
2-Hydroxy-4-methoxybenzophenone Control Formulation Composition
[0112]
TABLE-US-00014 2-Hydroxy-4- methoxybenzophenone PEG 400 PEG 1500 207.20 mg 1001.80 mg 754.04 mg [0113] Weigh PEG 400 and PEG 1500 into a beaker. The container was placed in a 35° C. oven. Mix until a clear solution was obtained. Weigh for 2-Hydroxy-4-methoxybenzophenone into the container containing PEG. Mix thoroughly. A clear solution was obtained
[0114] Mice Test Procedures: [0115] 1. Mice preparation and blood sample taking: Twelve mice were fed with adequate food and water for 3 days. Twelve hours before the test the food was removed and only water was given. The 12 mice were randomly divided into two groups. 2 hours before the test the mice were subjected to anesthesia and the hair on the back (2.0-2.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0116] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0117] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0118] 4. HPLC analysis: [0119] (4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; mobile phase: MeOH:0.14% H.sub.3PO.sub.4=65:35; Flow rate: 1.0 mL/min.; Wavelength: 290 nm; Injection volume: 20 μL;
[0120] 2-Hydroxy-4-methoxybenzophenone: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.: Mobile phase: MeOH:H.sub.2O=80:20; Flow rate: 1.0 mL/min.; Wavelength: 290 nm; Injection volume: 20 μL;
Example 7
Oxybenzone Formulation
2-Hydroxy-4-methoxybenzophenone Formulation Composition
[0121]
TABLE-US-00015 2-Hydroxy-4- methoxybenzophenone Polyethylenimine PEG 200 PEG 1500 101.67 mg 79.04 mg 509.98 mg 339.09 mg
[0122] Mix PEG 200 (509.98 mg) and PEG 1500 (339.09 mg) while heating gently until a homogeneous clear solution obtained. Dissolve 2-Hydroxy-4-methoxybenzophenone (101.67 mg) in PEG 200/PEG 1500 solution. Adding polyethyleneimine (PEI) (79.04 mg) yielded a clear yellowish ointment (1.03 g). The content of 2-Hydroxy-4-methoxybenzophenone is 9.9%.
[0123] Formulation Chemistry
[0124] The proton of the hydroxyl group of 2-hydroxy-4-methoxybenzophenone is somewhat acidic. The —NH.sub.2 amine groups of excipient polyethyleneimine will react with 2-Hydroxy-4-methoxybenzophenone to form an anion and ammonium cation. Due to the ionic interaction, the penetration of 2-Hydroxy-4-methoxybenzophenone moieties, the active UV ray blocking agent, through skin barrier into blood circulation system will be either dramatically reduced or eliminated.
Formulation Scheme of Oxybenzophenone/Polyethyleneimine
[0125] ##STR00026##
2-Hydroxy-4-methoxybenzophenone Control Formulation Composition
[0126]
TABLE-US-00016 2-Hydroxy-4- methoxybenzophenone PEG 400 PEG 1500 207.20 mg 1001.80 mg 754.04 mg
[0127] Weigh PEG 400 and PEG 1500 into a beaker. The beaker was placed in a 35° C. oven. Mix until a clear solution was obtained. Weigh for 2-Hydroxy-4-methoxybenzophenone into the container containing PEG. Mix thoroughly. A clear ointment was obtained.
[0128] Mice Test Procedures: [0129] 1. Mice preparation and blood sample taking: Thirty mice were fed with adequate food and water for 3 days. Twelve hours before the test the food was removed and only water was given. These 30 mice were randomly divided into two groups. Two hours before the test the mice were subjected to anesthesia and the hair on the back (2.0-2.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 90, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0130] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0131] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0132] 4. HPLC analysis: [0133] 2-Hydroxy-4-methoxybenzophenone: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; Mobile phase: MeOH:H.sub.2O=80:20; Flow rate: 1.0 mL/min.; Wavelength: 290 nm; Injection volume: 20 μL;
Example 8
Avobenzone Formulation
Avobenzone Formulation Composition
[0134]
TABLE-US-00017 Avobenzone Polyethylenimine PEG 200 PEG 1500 104.78 mg 102.17 mg 1109.95 mg 735.90 mg
[0135] Mix PEG 200 (1109.95 mg) and PEG 1500 (735.90 mg) while heating gently until a homogenous clear solution obtained. Dissolve avobenzone (104.78 mg) in PEG 200/PEG 1500 solution. Adding polyethyleneimine (102.17 mg) yielded a clear yellowish ointment (2.05 g). The content of 2-Hydroxy-4-methoxybenzophenone is 5.1%.
[0136] Formulation Chemistry
[0137] Avobenzone exists in enol form and beta di-ketone form. Enol form is energetically favorable than di-ketone form. The proton of the hydroxyl group of enol form is somewhat acidic. The NH.sub.2 amine groups of excipient polyethyleneimine (PEI) will react with the active proton to form enol anion and ammonium cation. Due to the ionic interaction, the penetration of avobenzone moieties, the active UV ray blocking agent, through skin into blood circulation system will be either dramatically reduced or completely eliminated.
##STR00027##
Avobenzone Control Formulation
[0138]
TABLE-US-00018 Avobenzone Iso-Propanol PEG 200 PEG 1500 101.51 mg 104.92 mg 1130.46 mg 742.77 mg [0139] Weigh PEG 200 and PEG 1500 into a beaker. The beaker was placed in a 35° C. oven. Mix until a clear solution was obtained. Weigh avobenzone into the container containing PEG. Mix thoroughly. A clear ointment was obtained.
[0140] Mice Test Procedures: [0141] 1. Mice preparation and blood sample taking: Thirty mice were fed with adequate food and water for 3 days. Twelve hours before the test the food was removed and only water was given. Twenty-four mice were randomly divided into two groups. Two hours before the test the mice were subjected to anesthesia and the hair on the back (2.0-2.5 cm.sup.2) was removed. After recovering from anesthesia one group of mice will be applied testing ointment sample while the other group will be applied with control standard sample. At 5, 15, 30, 60, 90, 120 min. blood sample (1 mL) will be collected after removing the eyes. [0142] 2. Blood sample pretreatment: after the blood sample was taken, it was immediately subjected to centrifugation 10 min. at 12000 rpm, supernatant plasma layer was taken, preserved at −20° C. for later use. [0143] 3. Blood sample preparation: Accurately transfer 150 μL plasma sample to a 1.5 mL EP test tube. Add methanol and acetonitrile 200 μL, respectively. Vertex mix for 1 min., then centrifuge for 10 min. at 12000 rpm. Precisely transfer the supernatant solution to another test tube. At 40° C. blow N.sub.2 through to dryness. To the solids left add methanol 150 μL, vertex mix for 1 min. centrifuge at 12000 rpm for 10 min. Supernatant solution was used directly for HPLC analysis. [0144] 4. HPLC analysis: [0145] Avobenzone: Column: C18 RP column (250×4.6 mm, 5 μm); column temperature: 25° C.; mobile phase: MeOH:H.sub.2O=90:10; Flow rate: 1.0 mL/min.; Wavelength: 360 nm; Injection volume: 20 μL;
Example 9
Benzoic Acid Formulation Mice Skin Penetration Test Results
[0146] As shown in
Example 10
4-Methoxy-benzylamine Formulation Mice Skin Penetration Test Results
[0147] As shown in
Example 11
(4-Benzoyl-3-hydroxy-phenoxy)-acetic Acid Formulation Mice Skin Penetration Test Results
[0148] At the initial 30 min. the skin penetration rate of sunscreen agent was minimal. As shown in
Example 12
(4-Aminomethoxy-2-hydroxy-phenyl)-phenyl-methanone Formulation Mice Skin Penetration Test Results
[0149] As shown in
Example 13
Oxybenzone+PEI Formulation Mice Skin Penetration Test Results
[0150] As shown in
Example 14
Avobenzone+PEI Formulation Mice Skin Penetration Test Results
[0151] As shown in
[0152] The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims.