Recombinant human-basic fibroblast growth factor (rh-bFGF) and pharmaceutical composition comprising rh-bFGF

Provided are a mutated nucleic acid molecule of a recombinant human-basic fibroblast growth factor (rh-bFGF), a pharmaceutical composition of the rh-bFGF, and a use thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is the U.S. national stage entry, under 35 U.S.C. § 371, of International Application No. PCT/CN2017/089823, filed Jun. 23, 2017, the entire contents of which are hereby incorporated by reference.

SEQUENCE LISTING

The sequence listing is filed with the application in electronic format only and is incorporated by reference herein. The sequence listing text file “023704-9014-US01_as_filed_Sequence_Listing.txt” was created on Dec. 19, 2019 and is 6,029 bytes in size.

TECHNICAL FIELD

The invention relates to the field of DNA recombination and biopharmaceuticals. More specifically, the invention relates to a mutated nucleic acid molecule encoding a recombinant human-basic fibroblast growth factor (rh-bFGF), a pharmaceutical composition comprising the rh-bFGF, and use of the pharmaceutical composition for treating dry eye.

BACKGROUND TECHNIQUE

Dry eye is a general term for various diseases caused by abnormalities in tear quality or kinetics caused by any cause, resulting in decreased tear film stability, and accompanied by eye discomfort and/or ocular surface tissue lesions, also known as keratoconjunctivitis sicca.

When various causes, such as reduce in the production of tear film liquid tear, abnormal mucus secretion and meibomian gland dysfunction, cause the absolute and relative lack of tear film components, abnormal distribution of tears on the ocular surface, and increase in tear evaporation, dry eye can be caused.

Common symptoms include dry eyes, easy fatigue, itchy eyes, foreign body sensation, burning sensation, thick secretions, fear of wind, photophobia, sensitivity to external stimuli; sometimes the eyes are too dry, the basic tears are insufficient, which in turns stimulates reflexive tear secretion, causing frequent lachrymation; in severe cases, the eyes will be red, swollen, keratinized, and the corneal epithelium will be broken with filaments adhered. This damage can cause keratoconjunctival lesions and affect vision in a long term.

Nowadays, the number of patients with dry eye is increasing. Currently, commercially available products such as sodium hyaluronate eye drops, polyvinyl alcohol eye drops, polyethylene glycol eye drops, etc. can alleviate dry eye symptoms, but can only act as artificial tears. The natural tear is complex in composition, and the integrity of the three-layer structure of the natural tear film is the basis for the implementation of its effective function, but the natural tear cannot be completely replaced with an artificial tear.

In addition, preservatives are currently contained in commercially available products, and long-term use of preservative-containing drugs may cause damage to the ocular surface and may cause ocular surface diseases to be more severe.

There is currently no product using bFGF for treating dry eye, and no bFGF derived from human has been reported for treating dry eye.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a mutated nucleic acid molecule encoding a recombinant human-basic fibroblast growth factor (rh-bFGF).

In one aspect, the invention provides a recombinant human-basic fibroblast growth factor (rh-bFGF) encoded by the mutated nucleic acid molecule.

In one aspect, the invention provides a pharmaceutical composition comprising the recombinant human-basic fibroblast growth factor (rh-bFGF) and at least one pharmaceutically acceptable excipient.

In one aspect, the invention provides a pharmaceutical composition comprising the recombinant human-basic fibroblast growth factor (rh-bFGF) and at least one stabilizer selected from the group consisting of glycine, histidine, arginine, Tween, heparin sodium or human serum albumin (HSA).

In one aspect, the pharmaceutical composition is free of preservatives.

In one aspect, the invention provides a method of treating dry eye, the method comprising administering to a patient in need thereof a therapeutically effective amount of the pharmaceutical composition.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the inventors have for the first time developed a pharmaceutical composition comprising a recombinant human-basic fibroblast growth factor and one or more pharmaceutically acceptable excipients.

In one aspect, the invention provides a pharmaceutical composition comprising the recombinant human-basic fibroblast growth factor (rh-bFGF) and at least one stabilizer selected from the group consisting of glycine, histidine, arginine, Tween, heparin sodium or human serum albumin (HSA). In this regard, it has unexpectedly been found that the recombinant human-basic fibroblast growth factor and the stabilizer constitute a specific stable combination.

In one aspect, the pharmaceutical composition is free of preservatives.

In one aspect, the invention provides a mutated nucleic acid molecule encoding the recombinant human-basic fibroblast growth factor (rh-bFGF). In one aspect, the invention provides a mutated nucleic acid molecule encoding the recombinant human-basic fibroblast growth factor (rh-bFGF), which comprises a sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3, or comprises a sequence having at least 95%, 96%, 97%, 98% or 99% identity to SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3. In one aspect, the invention provides a mutated nucleic acid molecule encoding the recombinant human-basic fibroblast growth factor (rh-bFGF), which has the sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3.

In one aspect, the invention provides a recombinant human-basic fibroblast growth factor (rh-bFGF) encoded by the mutated nucleic acid molecule.

In one aspect, the invention provides a pharmaceutical composition comprising the recombinant human-basic fibroblast growth factor (rh-bFGF) and at least one pharmaceutically acceptable excipient. In one aspect, the excipient includes, but is not limited to, a buffer system, a thickener, a stabilizer, a neutralizing agent, a humectant, and the like.

In one aspect, the present invention provides a pharmaceutical composition comprising the recombinant human-basic fibroblast growth factor (rh-bFGF) and at least one stabilizer selected from the group consisting of glycine, histidine, arginine, Tween, heparin sodium or human serum albumin (HSA).

In one aspect, the excipient comprises a buffer system. The buffer system includes, but is not limited to, sodium dihydrogen phosphate-disodium hydrogen phosphate, citric acid-disodium hydrogen phosphate or boric acid-borax. In one aspect, the buffer system is sodium dihydrogen phosphate-disodium hydrogen phosphate. In one aspect, the buffer system is citric acid-disodium hydrogen phosphate.

In one aspect, when sodium dihydrogen phosphate and disodium hydrogen phosphate are used as the buffer system, sodium dihydrogen phosphate and disodium hydrogen phosphate are present at concentrations of 0.25 mg/mL-1.25 mg/mL and 1.25 mg/mL-3.75 mg/mL, respectively.

In one aspect, when sodium dihydrogen phosphate and disodium hydrogen phosphate are used as the buffer system, sodium dihydrogen phosphate and disodium hydrogen phosphate are present at concentrations of 0.2-2.5 mg/mL and 0.5-5.0 mg/mL and 0.5-5.0 mg/mL, respectively.

In one aspect, when sodium dihydrogen phosphate and disodium hydrogen phosphate are used as the buffer system, sodium dihydrogen phosphate and disodium hydrogen phosphate are present at concentrations of 0.425 mg/mL and 2.50 mg/mL, respectively.

In one aspect, the excipient comprises a thickener. The thickener includes, but is not limited to, polyvinyl alcohol, sodium hyaluronate, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hypromellose, poloxamer or carbomer thickener. In one aspect, the thickener is polyvinyl alcohol. In one aspect, the thickener is a carbomer. In one aspect, the carbomer is such as a series of Carbomer 940, Carbomer 934, Carbomer 974, Carbomer 980, etc., preferably a Carbomer 980 series.

In one aspect, when polyvinyl alcohol is used as the thickener, the amount of polyvinyl alcohol in the composition is typically 5.0 mg/mL, 6.0 mg/mL, 7.0 mg/mL, 8.0 mg/mL, 9.0 mg/mL, 10.0 mg/mL.

In one aspect, when carbomer is used as the thickener, the amount of carbomer in the composition is typically 5.0 mg/mL, 6.0 mg/mL, 7.0 mg/mL, 8.0 mg/mL, 9.0 mg/mL, 10.0 mg/mL.

In one aspect, the excipient comprises a stabilizer. Such stabilizer includes, but is not limited to, heparin sodium, human serum albumin (HSA), glycine, histidine, arginine, Tween, or a combination of two or more thereof. In one aspect, the stabilizer is heparin sodium and human serum albumin (HSA). In one aspect, the stabilizer is human serum albumin (HSA). In one aspect, the stabilizer is glycine. In one aspect, the stabilizer is histidine. In one aspect, the stabilizer is arginine. In one aspect, the stabilizer is Tween, such as Tween-20.

In one aspect, when human serum albumin is used as the stabilizer, the amount of human serum albumin in the composition is typically 0.01-10.0 mg/mL, such as 0.03-10.0 mg/mL.

In one aspect, when glycine, histidine, or arginine is used as the stabilizer, the amount of glycine, histidine, or arginine in the composition is typically 2%-5% (w/v), such as 2%, 3%, 4% or 5%.

In one aspect, the excipient comprises a neutralizing agent. The neutralizing agent includes, but is not limited to, triethanolamine, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate or borax. In one aspect, the neutralizing agent is triethanolamine.

In one aspect, the neutralizing agent is typically present at a concentration of 1.25-12.5 mg/mL, such as 5 mg/mL, 6 mg/mL, 7 mg/mL, 8 mg/mL, 9 mg/mL or 10 mg/mL. In one aspect, when triethanolamine is used as the neutralizing agent, the amount of triethanolamine in the composition is typically 5-12.5 mg/mL, such as 5 mg/mL, 6 mg/mL, 7 mg/mL, 8 mg/mL, 9 mg/mL or 10 mg/mL.

In one aspect, the excipient comprises a humectant. The humectant includes, but is not limited to, glycerin, propylene glycol or a mixture thereof.

In one aspect, the humectant is typically present at a concentration of 0.1-50.0 mg/mL. In one aspect, when glycerol is used as the humectant, the amount of glycerin in the composition is typically 12.5-50.0 mg/mL, such as 12.5-25.0 mg/mL, 25.0-50.0 mg/mL, such as 25.0 mg/mL.

In one aspect, the composition is buffered to a pH of about 6.0-8.0, such as a pH of 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9 or 8.0 or a pH defined by any range therebetween.

In one aspect, the invention provides a method of treating dry eye, the method comprising administering to a patient in need thereof a therapeutically effective amount of the pharmaceutical composition.

In one aspect, the invention provides the pharmaceutical composition for use in treating dry eye.

In one aspect, the invention provides use of the pharmaceutical composition for treating dry eye.

In one aspect, the invention also provides use of the composition in the manufacture of a medicament for treating dry eye.

In one aspect, the pharmaceutical composition of the invention can be administered by a variety of routes of administration, such as by ocular administration to a patient in need thereof, such as administration by conjunctiva.

The pharmaceutical composition of the invention can be administered in various dosage forms, for example, as a solution, a suspension, an emulsion, a microemulsion, a composite emulsion, a drop, a gel, a spray, an eye drop, an ophthalmic ointment, or an ophthalmic lotion and an injection.

In one aspect, the pharmaceutical composition of the invention is an ophthalmic pharmaceutical composition. In particular, the pharmaceutical composition of the invention is in the form of an eye drop or a gel.

An advantage of the pharmaceutical composition of the present invention is that the rh-bFGF and the stabilizer such as glycine, histidine, arginine, Tween, heparin sodium or human serum albumin (HSA) unexpectedly constitute a specific stable combination. In particular, glycine, histidine, arginine, Tween, heparin sodium or human serum albumin (HSA) significantly improves the stability of rh-bFGF. Furthermore, the humanized bFGF of the invention is immunologically safer than non-human derived bFGF.

The invention is further described with reference to the following non-limiting examples.

EXAMPLE

Example 1. Nucleic Acid Mutation

The cDNA sequence (SEQ ID NO: 4) encoding the native human bFGF was mutated without changing the amino acid sequence of the protein, and three mutated cDNA sequences were designed and synthesized (mutated cDNA Sequence 1, Sequence 2 and

Sequence 3 as showed by SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3, respectively):

Example 2. Prokaryotic Expression and Protein Characterization

2.1 Expression and Purification

The expression vector used was pET-30a(+) (seeFIG. 1) and was purchased from Merk KgsA co. (Cat. No. 69909-3). The vector carries a T7 promoter, a T7 transcription initiation site, a His Tag, a coding sequence, an S Tag coding sequence, multiple cloning sites (MCSs), a T7 terminator, a lactose coding sequence, a kan resistance coding sequence, and a pBR322 replicon and a f1 replicon. The MCSs comprise the restriction sites XhoI, NotI, EagI, HindIII, SalI, SacI, EcoRI, BamHI, EcoRV, NcoI, KpnI, BglII, NspV, and NdeI.

For ease of cloning, a NdeI restriction site was designed upstream of the start codon of the Sequence 1 (SEQ ID NO: 1) and a HindIII restriction site was designed near the terminator. The 480 bps sequence was achieved by gene synthesis through chemical method. The sequence was double-digested with NdeI and HindIII and then inserted into the same double-digested expression vector pET-30a(+) to obtain a 5724 bps recombinant plasmid, which was transformed into DH5a (TaKaRa, 9057) by heat shock method and cultured in LB medium containing 50 ng/mL kanamycin. Monoclones were selected and the correct transformants were screened by NdeI and HindIII double digestion. The correctness of the transformants was verified again by sequencing.

In another example, pET-28a(+), pET-23c(+) or pET-15b or the like can be used in place of the above pET-30a(+) vector.

The prokaryotic expression vector containing the protein sequence was transformed intoE. coliBL21 (DE3), and the soluble human bFGF was induced to be expressed by adjusting the bacterial culture temperature, the induction temperature, the pH range, the glucose concentration, and the inducer concentration. The bacteria were collected by washing and filtering through hollow fiber; the fermented bacteria were disrupted by using high-pressure homogenization and maintaining at a low temperature; after adding an appropriate amount of nonionic surfactant, the supernatant was collected by low-temperature high-speed centrifugation, and the pellet was discarded.

Purification was carried out by use of a process such as weak cation exchange, heparin affinity chromatography or the like, and an appropriate amount of a protective agent such as mercaptoethanol, DTT or the like was added during the purification. After the sample was purified by the above procedures, its purity was up to 95% and more. Experiments confirmed that about 600 mg of recombinant human bFGF protein could be prepared per 100 g of bacteria, and a significant high expression has been achieved.

2.2 Purity and Molecular Weight Detection and Sequencing

15% SDS-PAGE electrophoresis showed that the human bFGF protein as obtained was a single band of approximately 18.5 KD (seeFIG. 2). The detection results of the high performance liquid chromatography with a C8 reverse phase column showed that the purity of the human bFGF as obtained in the present invention was more than 95% (seeFIG. 3).

“Ultra-high resolution, ultra-high accuracy, ultra-high sensitivity” Exactive Plus EMR was used for accurate molecular weight determination, and 6 components (components 1, 4, 5 ratios basically >10%, table 1) were detected in 4 batches of rh-bFGF stock solutions. Component 4 is the main component, and has an average molecular weight of 17121.02 Da; the inter-batch RSD % is 0.0007, with a deviation from the theoretical value of <41 ppm, and the relative ratio (calculated as peak intensity) is 70.7%-79.0%.

In addition, the recombinantly prepared human bFGF protein (SEQ ID NO: 6) was analyzed for amino acid sequence, and it was confirmed that the amino acid sequence thereof was identical to that of native human bFGF (SEQ ID NO: 5; seeFIG. 5).

2.3 Biological Activity Assay

The samples were tested for in vitro activity using balb/c3T3 cells. Cell proliferation was judged by MTT assay. The results showed that the effect of promoting proliferation of balb/c3T3 cells by the obtained human bFGF was consistent with that by the bFGF active standard (NISCB) (seeFIG. 6).

Example 3. Preparation of Pharmaceutical Compositions

1. The buffer system may be the above sodium dihydrogen phosphate and disodium hydrogen phosphate, or a boric acid-borax buffer system, a citric acid-disodium hydrogen phosphate buffer system or the like. Preferably, the pharmaceutical composition has a pH of from 6.5 to 7.5.

2. The thickener is polyvinyl alcohol, sodium hyaluronate, hypromellose, poloxamer, or the like, and preferably polyvinyl alcohol.

(1) Polyvinyl alcohol is dispersed and dissolved in an appropriate amount of water for injection, autoclaved at 121° C. for 30 min, cooled to room temperature, and ready for use;

(2) Recombinant human-basic fibroblast growth factor, human serum albumin, heparin sodium, sodium chloride, sodium dihydrogen phosphate, and disodium hydrogen phosphate are dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) are uniformly mixed under a sterile condition, made up to the fixed volume with sterile water for injection, and thus obtained;

(4) The sterile solution is filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount is 0.4 mL, and thus the finished product is obtained.

(1) Carbomer is dispersed in an appropriate amount of water for injection, stirred uniformly, and then swelled overnight, and ready for use;

(2) Triethanolamine is added to the carbomer dispersion, stirred into a transparent uniform gel base, autoclaved at 121° C. for 30 min, cooled to room temperature after sterilization is completed, and ready for use;

(3) Glycerol, human serum albumin, heparin sodium, and recombinant human-basic fibroblast growth factor are added into an appropriate amount of room temperature water for injection, stirred uniformly, and then passed through a 0.22 μm filter membrane under a sterile condition, mixed with the gel base in the step (2), and then quantified and stirred uniformly;

(4) The sterile gel is filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount is 0.4 g, and thus the finished product is obtained.

1. The buffer salt system may be the above sodium dihydrogen phosphate and disodium hydrogen phosphate, or a boric acid-borax buffer system, a citric acid-disodium hydrogen phosphate buffer system or the like; preferably, the pH is from 6.5 to 7.5.

2. The thickener is polyvinyl alcohol, sodium hyaluronate, hypromellose, poloxamer, or the like, and preferably polyvinyl alcohol. The humectant is glycerin, propylene glycol or a mixture thereof.

(1) The thickener and sodium chloride are dispersed and dissolved in an appropriate amount of water for injection, and autoclaved at 121° C. for 30 min;

(2) Recombinant human-basic fibroblast growth factor, human serum albumin, humectant, sodium dihydrogen phosphate, and disodium hydrogen phosphate are dissolved in an appropriate amount of water for injection;

(3) The agent solution in the step (2) is filtered through a 0.22 μm microporous filter membrane and then mixed with the agent solution obtained in the step (1), and made up to 1 mL with water for injection;

(4) The agent solution obtained in the step (3) is filled into a packaging container containing no bacteriostatic agent, and the volume of the container is in the range of 0.4 g/piece, and thus, the finished product is obtained.

In addition, the following pharmaceutical compositions (see Table 2) were also prepared. Among them, the eye drops were prepared as 100 ml, and the external gels were prepared as 100 g.

Preparation Example 1

(1) 1.0 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 500000 IU of recombinant human-basic fibroblast growth factor, 25 mg of human serum albumin, 2.5 mg of heparin sodium, 800 mg of sodium chloride, 42.5 mg of sodium dihydrogen phosphate, and 250 mg of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 2

(1) 0.5 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 500000 IU of recombinant human-basic fibroblast growth factor, 20 mg of human serum albumin, 2.0 mg of heparin sodium, 800 mg of sodium chloride, 42.5 mg of sodium dihydrogen phosphate, and 250 mg of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 3

(1) 1.0 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 420000 IU of recombinant human-basic fibroblast growth factor, 20 mg of human serum albumin, 2.0 mg of heparin sodium, 800 mg of sodium chloride, 42.5 mg of sodium dihydrogen phosphate, and 250 mg of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 4

(1) 1.5 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 420000 IU of recombinant human-basic fibroblast growth factor, 10 mg of human serum albumin, 1.0 mg of heparin sodium, 800 mg of sodium chloride, 42.5 mg of sodium dihydrogen phosphate, and 250 mg of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 5

(1) 1.0 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 420000 IU of recombinant human-basic fibroblast growth factor, 20 mg of human serum albumin, 2.0 mg of heparin sodium, 800 mg of sodium chloride, 370.6 mg of citric acid, and 5.9 g of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 6

(1) 1.0 g of polyvinyl alcohol was dispersed and dissolved in an appropriate amount of water for injection, autoclaved, cooled to room temperature, and ready for use;

(2) 500000 IU of recombinant human-basic fibroblast growth factor, 25 mg of human serum albumin, 2.5 mg of heparin sodium, 800 mg of sodium chloride, 370.6 mg of citric acid, and 5.9 g of disodium hydrogen phosphate were dissolved in an appropriate amount of water for injection, and sterile filtered through a 0.22 μm filter membrane;

(3) The solutions obtained in the step (1) and in the step (2) were uniformly mixed under a sterile condition, made up to 100 mL with sterile water for injection, and thus obtained;

(4) The sterile solution was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 mL, and thus the finished product was obtained.

Preparation Example 7

(1) 0.80 g of Carbomer 940 was weighted and dispersed in an appropriate amount of room temperature water for injection, stirred for 60-120 min, swelled overnight, and ready for use;

(2) 0.60 g of triethanolamine was added to the Carbomer 940 dispersion, stirred into a transparent uniform gel base, and then subjected to moist heat sterilization (121° C., 30 min), cooled to room temperature after sterilization was completed, and ready for use;

(3) 2.50 g of glycerol, 30.0 mg of human serum albumin, 7.0 mg of heparin sodium, and 450000 IU of recombinant human-basic fibroblast growth factor were added into an appropriate amount of room temperature water for injection, stirred uniformly, and then passed through a 0.22 μm filter membrane under a sterile condition, mixed with the gel base in the step (2), and then quantified and stirred uniformly;

(4) The sterile gel was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 g, and thus the finished product was obtained.

Preparation Example 8

(1) 0.60 g of Carbomer 940 was weighted and dispersed in an appropriate amount of room temperature water for injection, stirred for 60-120 min, swelled overnight, and ready for use;

(2) 0.50 g of triethanolamine was added to the Carbomer 940 dispersion, stirred into a transparent uniform gel base, and then subjected to moist heat sterilization (121° C., 30 min), cooled to room temperature after sterilization was completed, and ready for use;

(3) 2.50 g of glycerol, 30.0 mg of human serum albumin, 7.0 mg of heparin sodium, and 420000 IU of recombinant human-basic fibroblast growth factor were added into an appropriate amount of room temperature water for injection, stirred uniformly, and then passed through a 0.22 μm filter membrane under a sterile condition, mixed with the gel base in the step (2), and then quantified and stirred uniformly;

(4) The sterile gel was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 g, and thus the finished product was obtained.

Preparation Example 9

(1) 0.60 g of Carbomer 974 was weighted and dispersed in an appropriate amount of room temperature water for injection, stirred for 60-120 min, swelled overnight, and ready for use;

(2) 0.50 g of triethanolamine was added to the Carbomer 974 dispersion, stirred into a transparent uniform gel base, and then subjected to moist heat sterilization (121° C., 30 min), cooled to room temperature after sterilization was completed, and ready for use;

(3) 2.50 g of glycerol, 30.0 mg of human serum albumin, 7.0 mg of heparin sodium, and 450000 IU of recombinant human-basic fibroblast growth factor were added into an appropriate amount of room temperature water for injection, stirred uniformly, and then passed through a 0.22 μm filter membrane under a sterile condition, mixed with the gel base in the step (2), and then quantified and stirred uniformly;

(4) The sterile gel was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 g, and thus the finished product was obtained.

Preparation Example 10

(1) 0.50 g of Carbomer 974 was weighted and dispersed in an appropriate amount of room temperature water for injection, stirred for 60-120 min, swelled overnight, and ready for use;

(2) 0.50 g of triethanolamine was added to the Carbomer 974 dispersion, stirred into a transparent uniform gel base, and then subjected to moist heat sterilization (121° C., 30 min), cooled to room temperature after sterilization was completed, and ready for use;

(3) 2.50 g of glycerol, 20.0 mg of human serum albumin, 5.0 mg of heparin sodium, and 420000 IU of recombinant human-basic fibroblast growth factor were added into an appropriate amount of room temperature water for injection, stirred uniformly, and then passed through a 0.22 μm filter membrane under a sterile condition, mixed with the gel base in the step (2), and then quantified and stirred uniformly;

(4) The sterile gel was filled by using a three-in-one filling machine of blowing, filling and sealing, and the filling amount was 0.4 g, and thus the finished product was obtained.

Example 4. Stability Study

1) Study of the Effect of Amino Acids on the Stability of the Rh-bFGF Stock Solution

The rh-bFGF stock solution itself is unstable in nature, and tends to polymerize and thus precipitate at room temperature. Therefore, different stabilizers were selected and used, and primarily screened for the stability of the stock solution. 5% and 2% mannitol, 5% and 2% glycine, and 2% dextran were selected and used, and allowed to stand at 25° C. environment for 17 days. Protein concentrations were measured on days 0, 7, and 17, respectively, and the results are shown in Table 3.

TABLE 3Rate of change in protein concentration of the rh-bFGFstock solution in the screening test of stabilizersSampleDay 0Day 7Day 17No stabilizer100.00%29.96%13.63%5% mannitol100.00%49.80%17.31%2% mannitol100.00%53.29%15.66%5% glycine100.00%95.67%86.26%2% glycine100.00%94.74%82.73%2% dextran100.00%51.65%16.20%

The results showed that 5% glycine was effective in preventing protein from precipitation. There remained 86.26% protein after being placed under the thermal destructive condition for 17 days. After 17 days, the effect of glycine was significantly better than that of mannitol and dextran, while only 13.6% of the protein was left with no stabilizer added.

2) Study of the Effect of Histidine on the Stability of the Rh-bFGF Stock Solution

Different amino acids (glycine, histidine, arginine) and Tween 20 were selected and used, and further screened for the stability of the stock solution, and allowed to stand at 25° C. environment for 18 h. The results are shown inFIG. 7.

The results showed that 3% histidine and 0.03% Tween 20 were more effective than 5% glycine with respect to the stability of the rh-bFGF stock solution. The purity of the protein could still be maintained above 85% after being placed under the thermal destructive condition for 18 h. Histidine and Tween 20 were superior to glycine in protecting rh-bFGF.

3) Study of the Effect of HSA on the Stability of Rh-bFGF Stock Solution

Since HSA would interfere with the determination of protein content, the stock solutions with or without HSA were placed at 25° C. environment for 18 h, and change in the purity of the protein after being subjected to heat-damage was detected by high-resolution chromatography. The results are shown inFIG. 8.

The results showed that HSA could significantly improve the stability of rh-bFGF. With a change rate of 95% purity as an indicator, samples containing no HSA can only be maintained for 4 h under the stress condition, and can be extended to 15 hours after addition of HSA. It has been shown that HSA is an excellent protein protectant for bFGF.

Example 5. Study on the Efficacy in an Animal Dry Eye Model

In this study, New Zealand rabbit dry eye model was selected and used, the clinical indicators (tear secretion, and tear film break-up time) of the model were observed, and the clinical treatment effect of the medicament for dry eye was evaluated. New Zealand rabbits were divided into negative control group (Negative control, untreated), model control group (Model, treated with alkali burn but no any eye drops were added), treatment group with sodium hyaluronate eye drop (HA group), and the Group D (4.0 μg/mL), E (8.0 μg/mL), F (16.0 μg/mL), and G (32.0 μg/mL) which were divided according to the concentration of the rh-bFGF eye drops of Preparation Example 3 as used. The negative control group had 72 rabbits/group, and the remaining groups had 8 rabbits/group. The dosage was 300 μl/eye/day.

(1) Method for Measuring the Amount of Tear Secretion (Both Eyes) (the Wet Length of Phenol Red Cotton Thread):

The secretion of tears from New Zealand rabbits was measured using the Schirmer I test. That is, the phenol red cotton thread was clamped with ophthalmic forceps, and placed in the outer canthus of the New Zealand rabbit. After 60 s, the phenol red cotton thread was taken out and measured for the wet length. The phenol red cotton thread turned red after being wet, and the eye wetness was determined according to the wet length. The experimental results are shown inFIG. 9.

As shown inFIG. 9, the wet lengths of the phenol red cotton thread in the model control group all were significantly decreased as compared with those in the negative control eyes. On day 10 of administration, the wet lengths of the phenol red cotton thread in the rh-bFGF eye drops D, E, F, and G groups all were significantly longer with statistically significant differences, as compared with the model control group.

(2) Method for Measuring Tear Film Break-Up Time (Both Eyes):

2 μl of 0.5% sodium fluorescein solution was instilled into the lower eyelid conjunctival sac of New Zealand rabbit eyes using an adjustable pipette. After several times of manual blinking with constant force, the rabbit eyes were opened with a constant force and the cornea was observed with a slit lamp microscope and cobalt blue light. When a black area appears in the corneal green film, the tear film is indicated to be broken. Three measurements were taken continuously and the average value was taken. Less than 10 seconds of the tear film break-up time indicates that the tear film is unstable, which is a prominent marker of KCS caused by the lack of mucin in tears, suggesting that the goblet cells of the conjunctiva are seriously damaged or lost, and it is easy to cause dry eye. The experimental results are shown inFIG. 10.

As shown inFIG. 10, the tear film break-up times of the model control group all were significantly shorter than those of the negative control eyes on day 10 of administration, as compared to the negative control eyes. On day 10 of administration, the tear film break-up time of the rh-bFGF eye drops D, E, F, and G groups all were significantly prolonged with statistically significant differences, as compared with the model control group.

In summary, the results of the phenol red cotton thread test of the tear secretion showed that the eye drops of the present invention could improve the tear secretion amount of the model animals (seeFIG. 9); the tear film break-up time test showed that there was a significant improvement in the tear film break-up time in the dry eye model (seeFIG. 10). With an increase in dosage, rh-bFGF eye drops had a significant improvement on the dry eye model of alkal burned New Zealand rabbits.

Various modifications, substitutions, changes and equivalents will occur to those skilled in the art, although some features of the present invention has been set forth and illustrated herein. Therefore, it is to be understood that the appended claims are intended to cover all such modifications and changes that fall into the true spirit and scope of the present invention.