58 results about "Ranitidine" patented technology

A first, solid oral pharmaceutical composition includes an extended release acetaminophen, a non-steroidal anti-inflammatory drug, such as naproxen or ibuprofen, and a third drug capable of reducing gastric acid secretion, such as ranitidine or omeprazole. A second, solid oral pharmaceutical composition includes a non-steroidal anti-inflammatory drug and an agent for reducing gastric acid secretion.

A stick of gum is provided containing therapeutic benefits of non-steroid anti-inflammatory drugs for inflammation in conditions such as arthritis, and also alleviates subsequent side effects of NSAID administration, as well as antacid effects from compounds such as an H2 antagonist (ranitidine, cimetidine, famotidine) and / or a proton pump inhibitor (such as lansoprazole, pantoprazole, omeprazole, esomeprazole or rabeprazole) and / or an acid pump antagonist selected from the group of soraprazan, AZD0865, YH1885 and CS-526.

The invention relates to a Chinese-Western compound preparation for treating the infective proventriculitis of a chicken. The Chinese-Western compound preparation is characterized by comprising the following raw materials by weight percentage: 10-30% of elecampane, 5-15% of Chinese atractylodes, 10-20% of cortex magnoliae officinalis, 5-15% of liquorice, 10-20% of hawthorn, 0.3-0.5% of gentamicin,0.5-1% of ranitidine, and the balance of medicated leaven. The preparation method comprises the following steps: comminuting and sieving elecampane, Chinese atractylodes, cortex magnoliae officinalis, liquorice, hawthorn and medicated leaven respectively according to the weight percentage, then sufficiently mixing with gentamicin and ranitidine for 1 h to obtain the Chinese-Western compound preparation. The invention has the advantages that the Chinese-Western medicines are combined to make up the respective shortcomings of the Chinese-Western medicine. When used together, the traditional Chinese medicines have radical treatment for proventriculitis. For the decreased activity of pepsin, the Western medicine can inhibit the gastric acid secretion caused by histamine, pentagastrin and M cholinoceptor agonist. When combined to treat the infective proventriculitis of the chicken, the Chinese-Western medicines have very fast effect and can treat the infective proventriculitis temporarilyand radically; the frequency of administration can be reduced, the focus can be restored and the loss of culturist is reduced.

The present invention discloses a method for preparing ranitidine bismuth citrate. Said method includes the following steps: making bismuth citrate be suspended in water, adding ranitidine and ammonia water to make reaction, the mole ratio of bismuth citrate, ammonia and ranitidine is 1:1-10:0.9, controlling reaction system pH value and making it be 6-12, its reaction temperature is 4-64deg.C, monitoring pH value, after the pH value is reached to neutrality, stopping reaction, filtering reaction solution and spray-drying so as to obtain the invented ranitidine bismuth citrate.

The invention relates to a method using alkaline hydrolysis to prepare cysteamine hydrochloride, in particular to synthesizing cysteamine hydrochloride in alkali surroundings, which is characterized in that: ethanolamine solution and sulfate solution are used as raw material; 2- amino ethyl sulfate is firstly synthesized before made into ring in alkaline solution by 2-amino ethyl sulfate and carbon disulfide, thereby getting Alpha -mercaptothiazoline; alkaline hydrolysis is made upon Alpha -mercaptothiazoline to produce cysteamine hydrochloride. The preparation method for cysteamine hydrochloride by using alkaline hydrolysis has the advantages of simple method, short production period and low production cost. The recovery rate of synthesizing Alpha -mercaptothiazoline reaches more than 90%. The cysteamine hydrochloride can be widely applied in manufacturing anti-ulcer drugs such as ranitidine and cimetidine, manufacturing animal fodder additive, manufacturing cosmetic and hair wave-setting agent, manufacturing biochemical reagent and heavy metal ion complexion agent and manufacturing agent treating radiation syndrome and acute tetraethyl lead poisoning and in other areas.

The invention provides a method for preparing a traditional Chinese medicine for treating liver-qi attacking stomach type gastritis, which belongs to the traditional Chinese medicine preparation method technical field. Currently, ranitidine is taken as a medicine for treating liver-qi attacking stomach type gastritis which may cause certain adverse reaction. The technical scheme of the invention comprises the following steps: weighting trichosanthes kirilowii Maxim, bulbus allii macrostemi, tangerine seed, orange peel, orange, Chinese buckeye seed, tobacco, citron, nutgrass galingale rhizome, magnolia bark, lychee seed, lychee, radish seed, papaya, iris, carrot, buckwheat, medicated leaven, cydonia oblonga mill and licorice, immersing the above traditional Chinese medicines in water, then decocting by slow fire and filtering to remove slag. The decocted liquid medicine is the traditional Chinese medicine for treating liver-qi attacking stomach type gastritis. The traditional Chinese medicine for treating liver-qi attacking stomach type gastritis has the advantages of simple method, small toxic and side effect of prepared liquid medicine, short treatment course and high cure rate. The sovereign drug, minister drug, assistant drug and envoy drug are suitable in combination. The adverse reaction, anaphylactic reaction and toxic reaction caused by the western medicines can be avoided while the traditional Chinese medicine of the invention is used.

The present invention relates to the discovery that specific human taste receptors in the T2R taste receptor family respond to particular bitter ligands, i.e., acetaminophen, ranitidine, strychnine and denatonium. The present invention further relates to the use of these receptors in assays for identifying ligands that modulate the activation of these taste receptors and which may be used as additives in foods, beverages and medicinals for modifying (blocking) T2R-associated bitter taste.

The invention discloses a waste gas treatment and methyl mercaptan recycling process in cimetidine and ranitidine production. The waste gas treatment and methyl mercaptan recycling process comprises the following steps: (1) introducing waste gas in the production process of cimetidine and ranitidine into a washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are low in boiling point and easily soluble in water in the waste gas; (2) introducing the waste gas subjected to washing treatment into an alkaline washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are insoluble in water and soluble in alkaline by alkaline liquor in the alkaline washing tank; (3) introducing the waste gas subjected to the alkaline washing into a three-stage absorbing device, removing methyl mercaptan in the waste gas to generate sodium thiomethoxide; and (4) introducing the waste gas subjected to the three stages of absorption into a hydrogen peroxide falling film absorbing tower for performing oxidation treatment, and then discharging. According to the waste gas treatment and methyl mercaptan recycling process, useful chemical raw materials in the waste gas are recycled on the basis of solving the problem of waste gas emission, and thus the waste gas is prevented from being discharged, the economic benefit is increased, a new value is created, and the recycling economy is realized. The waste gas treatment and methyl mercaptan recycling process is good in application prospect.

The invention relates to ranitidine freeze-dried powder injection for curing gastropathy, in particular to a medicine composition. The powder injection comprises ranitidine, freeze-dry excipient and optional PH modifier, wherein the freeze-dry excipient is selected from mannitol, lactose, cane sugar, glucose, sorbitol, glycine, dextran, salt and the combinations thereof. The medicine composition comprises the following materials by 100 weight parts of ranitidine: 20-200 parts of freeze-dry excipient. The medicine composition is dissolved and diluted by water to an extent that 20 mg ranitidine is contained in the solution of 1ml, and the pH value of the solution is 4.5-6.5. The medicine composition has the advantages of superior pharmaceutical characters including favorable chemical stability.

The invention discloses a preparation method of a traditional Chinese medicine for treating pharyngalgia type reflux esophagitis and belongs to the technical field of the preparation method of the traditional Chinese medicine. The existing medicine for treating the pharyngalgia type reflux esophagitis is primarily ranitidine with contraindications for the people which are allergic to the medicine and other H2 receptors, pregnant women and breast feeding women. The technical scheme of the invention is as follows: the preparation method comprises the following steps of: putting and soaking 26 traditional Chinese medicines consisting of umbellate rockjasmine herb or fruit, orpine, fruticose breynia juvenile branchlet and leaf, hastate phymatopsis herb with root, blackberry lily, puffball (cloth bag), chinese lantern-plant, subprostrate sophora, Chinese white olive, manyleaf paris rhizome, diversecolor cinquefoil, radix berberidis, sticktight, Japanese cayratia herb, tuopangen, radix stellariae dichotomae, wood sorrel, ceanothus, villosulous veronicastrum herb or root, daghestan sweetclover herb, coffee senna, common alstonia bark or leaf, lophatherum gracile, mung bean, chrysanthemum and liquorice in water, decocting with slow fire, and filtering to remove the slag for co-decocting liquid medicine, wherein the decocted liquid medicine is the traditional Chinese medicine for treating the pharyngalgia type reflux esophagitis. The preparation method has the advantages that the prepared traditional Chinese liquid medicine is small in side effect, short in treatment course, high in recovery rate and capable of avoiding adverse reactions caused by antibacterial agents of Western medicine.

A slowly-released medicine of ranitidine in the form of dispersing solid is prepared from ranitidine and slow-releasing skeleton.

The invention discloses a preparation method of ranitidine bismuth citrate. The preparation method concretely comprises the following steps: (1) reacting ranitidine with bismuth citrate at the temperature of 90-95DEG C to obtain a solution containing ranitidine bismuth citrate; (2) cooling the solution containing ranitidine bismuth citrate to 50-60DEG C, adding activated carbon, preserving heat and decoloring for 20-30min; (3) carrying out suction filtration, adding the filtrate into homemade absolute ethyl alcohol and stirring and crystallizing, carrying out suction filtration, and drying a filter cake to obtain ranitidine bismuth citrate. The homemade absolute ethyl alcohol is obtained by adding sodium salt into the commercially available industrial-grade absolute ethyl alcohol, and stirring and filtering. According to the method, the trace impurities in the absolute ethyl alcohol can be greatly decreased, and further the maximum individual impurity in the ranitidine bismuth citrate can be reduced, the content of the maximum individual impurity can be reduced to less than 0.5%, and minimally to less than 0.3%, and the quality of products can be greatly improved.

The invention provides a preparation method of a traditional Chinese medicine for treating chili eating type reflux oesophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted to treat chili eating type reflux oesophagitis, but is used with caution to liver and kidney deficiency and old people. The preparation method is characterized by comprising the following steps of immersing the following 27 traditional Chinese medicines in water, namely galium aparine, dysosma versipellis, Indian stringbush root, saururus chinensis, radix berberidis, indigowoad leaf, garden euphorbia herb, christina loosestrife herb, rohdea japonica roth, aster ageratoides, subprostrate sophora, edible tulip, groundsel, huperzia serrata, Japanese stephania root, thymifoious euphorbia herb, meadowrue root and rhizome, purslane, Chinese coriaria leaf, baikal skullcap root, golden thread, golden cypress, broomjutre sida herb, iron holly bark, starwort root, Chinese rhubarb and liquorice; and decocting with slow fire to obtain decoction, which is the traditional Chinese medicine for treating chili eating type reflux oesophagitis. The traditional Chinese medicine has the advantages that adverse reactions, allergy reactions and toxicity reactions caused by Western antimicrobial agents while the traditional Chinese medicine is administrated.

The present invention is generally related to alcohol free, liquid ranitidine formulations for oral administration. In particular, the present invention is related to stable, syrup formulations having ranitidine as an active ingredient for oral administration, processes for making the same, and methods of their use. The ranitidine of the present invention is stable in non-polar media or media having a relatively low polarity such that the dielectric constant is less than about 60, and is achieved by using certain saccharides, certain relatively high molecular weight starches, and / or certain celluloses instead of alcohol.

The invention discloses a new chemical synthesizing method of 1-motol-1-methylmercapto-2-nitroethylene as one intermediate of ulcer drug ranitidine, which comprises the following steps: adopting nitromethane, carbon bisulphide and potassium hydroxide as initial reacting material; synthesizing 1, 1-dimethyldisulphide-2-nitro ethylene to dissolve in the water; reacting with aminomethane to synthesize new intermediate product; filtering to obtain the product.

The invention provides a preparation method of a traditional Chinese medicine for treating heat toxicity type reflux oesophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted for treating heat toxicity type reflux oesophagitis, but has a certain side effect. The preparation method is characterized by comprising the following steps of immersing the following traditional Chinese medicines in water, namely starwort root, creeping oxalis, buckthorn, veronicastrum herb, daghestan sweet clover herb, coffee senna seed, common alstonia bark leaf, lophatherum gracile, mungbean, dandelion, red-spotted stonecrop, shortstalk slimptop meadowrue root, breynia fruticosa, small-leaved desmodium, wintercherry, fresh golden thread, uniflower swisscentaury root, olive, taenitis carnosa mett, creeping rostellularia herb, gamboge, potentilla discolor, dutchmanspipe root, radix curcumae, shaddock, immature bitter orange, orange, selfheal, feather cockscomb seed, butterflybush flower, pipewort, scouring rush, chrysanthemum, mint, cicada slough, astragalus and liquorice; and decocting with slow fire to obtain decoction which is the traditional Chinese medicine for treating heat toxicity type reflux oesophagitis. The traditional Chinese medicine has the advantages that adverse reactions, allergy reactions and toxicity reactions caused by Western antimicrobial agents while the traditional Chinese medicine is administrated.

The invention discloses a chaenomeles speciosa (Sweet) Nakai extractive, and an extraction method and application thereof. Concretely, the extractive is chaenomeles speciosa (Sweet) Nakai total triterpenes and oleanolic acid separated from chaenomeles speciosa (Sweet) Nakai total triterpenes, and the extractive is applied to prepare medicine for preventing and treating gastric ulcer diseases. The extraction method comprises the following concrete steps: decoloring chaenomeles speciosa (Sweet) Nakai by using petroleum ether; then performing refluxing extraction on decolored chaenomeles speciosa (Sweet) Nakai by using ethyl acetate; then performing two times of decoloring, in other words, decoloring a chaenomeles speciosa (Sweet) Nakai extractum by using petroleum ether and then decoloring again by using active carbon; merging filtrates, and recovering ethanol, so as to obtain chaenomeles speciosa (Sweet) Nakai total triterpenes; and finally, performing recrystallization on the extracted chaenomeles speciosa (Sweet) Nakai total triterpenes for two times by using anhydrous ethanol, so as to obtain colorless oleanolic acid. The method is simple, and the product purity is high. The obtained chaenomeles speciosa (Sweet) Nakai total triterpenes and oleanolic acid both possess relatively good prevention and treatment effects, possess the effect better than that of ranitidine, also possess the advantages of small toxic and side effects and relatively good curative effect, and is worth exploiting and applying.

The invention provides a preparation method of a traditional Chinese medicine for treating chili eating type reflux oesophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted to treat chili eating type reflux oesophagitis, and contraindicated for use by patients allergic to ranitidine and other H2 receptor antagonists, pregnant women and breast feeding women. The preparation method is characterized by comprising the following steps of immersing the following 29 traditional Chinese medicines in water, namely monkshood, asarum, pepper, fructus piperis longi, piper cubeba, fennel, leek, galangal, fructus cnidii, chili, caraway, resurrection lily rhizome, radix aconiti, radix aconiti lateralis preparata, clove, fiveleaf akebia fruit, illicium verum, murraya jasminorage, aspongopus, sword bean, elecampane, szechwan Chinaberry fruit, mysorethorn, three-nerved spicebush root, rhizoma nardostachyos, ambergris, radix curcumae, green tangerine peel and liquorice; and decocting with slow fire to obtain decoction, which is the traditional Chinese medicine for treating chili eating type reflux oesophagitis. The traditional Chinese medicine has the advantages of simple manufacture, small toxic and side effect of prepared Chinese medicine decoction, short course of treatment and high cure rate. Monarch, minister, assistant and guide medicines are compatible.

The invention relates to a cosmetic which functions to remove acne and facial beautifying and skincare. The product made of the essences of traditional Chinese medicine and western drugs is for external use and invented by beauty expert Sun Min by combining the advantages of the treatments of acne in China and in the West. The product is prepared by rennin, ranitidine, Chinese goldthread injection solution, furacilin, metronidazole, boric acid solution and distilled water according to certain volume proportion and the components function coordinately to prevent and treat acne and beatify and protect skin. The invention has the functions of skin care, facial beautifying, prevention and treatment of acne, comedo, pimple, itch and skin toughness, etc., promotion of the recovery of acne scar and delicate, smooth and fair skin. The invention has scientific components, simple fabrication and unique treatment effect and can thoroughly cure acne without scar left and has good facial-beautifying effect.

The invention provides a preparation method of a traditional Chinese medicine for treating liver depression forming fire type reflux esophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted to treat liver depression forming fire type reflux esophagitis, and contraindicated for use by patients allergic to ranitidine and other H2 receptor antagonists, pregnant women, breast feeding women and children under eight. The preparation method is characterized by comprising the following steps of immersing the following 22 Chinese medicines in water, namely feather cockscomb seed, butterflybush flower, pipewort, scouring rush, chrysanthemum, mint, cicada slough, green tangerine peel, clove, fiveleaf akebia fruit, illicium verum, murraya jasminorage, aspongopus, sword bean, elecampane, szechwan Chinaberry fruit, mysorethorn, three-nerved spicebush root, rhizoma nardostachyos, ambergris, radix curcumae and liquorice; decocting with slow fire to obtain decoction. which is the traditional Chinese medicine for treating liver depression forming fire type reflux esophagitis. The traditional Chinese medicine has the advantages of short course of treatment and high cure rate. Monarch, minister, assistant and guide medicines are compatible. Adverse reactions, allergy reactions and toxic reactions caused by western antibacterial agents can be avoided while the traditional Chinese medicine is administrated.

The invention discloses a high performance liquid chromatography analysis method for nitrosamine substances in ranitidine drugs. The method comprises the following steps of (1) sample treatment; (2) preparing a sample solution; (3) preparing a control solution; and (4) chromatographic analysis. The ranitidine drug is subjected to drying and grinding treatment, low-temperature configuration under asealing condition, filtration before testing and other process conditions are set, so on one hand, stability and accuracy of an N-dimethyl nitrosamine test result are ensured; on the other hand, pollution of the sample to the chromatographic system is greatly reduced, the later use and maintenance are reduced, and maintenance cost is saved; on the basis of sample treatment, test analysis can be carried out by using a conventional high performance liquid chromatograph, accuracy is high, result reproducibility is good, a large amount of capital investment is not needed, cost is saved, and the method is suitable for industrial production and application and wide in market prospect.

The present invention is generally related to alcohol free, liquid ranitidine formulations for oral administration. In particular, the present invention is related to stable, syrup formulations having ranitidine as an active ingredient for oral administration, processes for making the same, and methods of their use. The ranitidine of the present invention is stable in non-polar media or media having a relatively low polarity such that the dielectric constant is less than about 60, and is achieved by using certain saccharides, certain relatively high molecular weight starches, and / or certain celluloses instead of alcohol.

A ranitidine micropill is composed of core and coating layer prepared from 3 substances. It can be further made into capsule or tablet. Its advantages are low hydroscopicity, high stability and quick disintegration in stomach.

The invention provides a preparation method of a traditional Chinese medicine for treating qi-deficiency reflux esophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted to treat qi-deficiency type reflux esophagitis, and contraindicated for use by patients allergic to ranitidine and other H2 receptor antagonists, pregnant women, breast feeding women and children under eight. The preparation method is characterized by comprising the following steps of immersing the following 21 traditional Chinese medicines in water, namely wheat, radix pseudostellariae, black-bone chicken, cabbage, longan pulp, bighead atractylodes rhizome, white peony root, American ginseng, Chinese angelica, lotus seed, codonopsis pilosula, fructus alpiniae oxyphyllae, astragalus, sealwort, polished round-grained rice, dried ginger, Chinese angelica, white peony root, longan pulp, ganoderma lucidum and liquorice; and decocting with slow fire to obtain decoction, which is the traditional Chinese medicine for treating qi-deficiency reflux esophagitis. The traditional Chinese medicine has the advantages of simple manufacture, small toxic and side effect of prepared Chinese medicine decoction, short course of treatment and high cure rate. Monarch, minister, assistant and guide medicines are compatible. Adverse reactions, allergy reactions and toxic reactions caused by Western medicaments sulfonamides and antibiotics can be avoided while the traditional Chinese medicine is administrated.

The present invention discloses a method for preparing ranitidine bismuth citrate. Said method includes the following steps: making bismuth citrate be suspended in water, adding ranitidine and ammonia water to make reaction, the mole ratio of bismuth citrate, ammonia and ranitidine is 1:1-10:0.9, controlling reaction system pH value and making it be 6-12, its reaction temperature is 4-64deg.C, monitoring pH value, after the pH value is reached to neutrality, stopping reaction, filtering reaction solution and spray-drying so as to obtain the invented ranitidine bismuth citrate.

The invention belongs to the technical field of in-vivo medicine detection, in particular to a method for detecting the concentration of tigecycline in blood plasma. According to the method for detecting the concentration of tigecycline in the blood plasma, ranitidine is adopted as an internal standard substance, and a high-performance liquid chromatograph is adopted for calculating the concentration of tigecycline in the blood plasma according to peak areas by means of an internal standard method under a certain chromatographic condition. The high-performance liquid chromatograph is adopted for detecting the concentration of tigecycline in the blood plasma, and the detection limitation can reach 0.028 microgram / mL. The method has the advantages of being high in accuracy and sensitivity, simple, high in detection speed and the like.

The invention provides a preparation method of a traditional Chinese medicine for treating stomach-yin deficiency type reflux oesophagitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, ranitidine is generally adopted to treat stomach-yin deficiency type reflux oesophagitis, and contraindicated for use by patients allergic to ranitidine and other H2 receptor antagonists, pregnant women, breast feeding women and children under eight. The preparation method is characterized by comprising the following steps of immersing the following 17 traditional Chinese medicines in water, namely radix scrophulariae, dwarf lilyturf root, radix asparagi, dendrobe, radix polygonati officinalis, lily, tortoise plastron, red-rooted salvia root, prepared rehmannia, mulberry, iris tectorum, carrot, buckwheat, medicated leaven, quince, raw rehmannia and liquorice; and decocting with slow fire to obtain decoction, which is the traditional Chinese medicine for treating stomach-yin deficiency type reflux oesophagitis. The traditional Chinese medicine has the advantages of simple manufacture, small toxic and side effect of prepared Chinese medicine decoction, short course of treatment and high cure rate. Monarch, minister, assistant and guide medicines are compatible. Adverse reactions, allergy reactions and toxic reactions caused by Western medicaments sulfonamides and antibiotics can be avoided while the traditional Chinese medicine is administrated.

The invention provides a ramosetron composition for injection, and relates to the technical field of medicines and medicine manufacturing. Main medicines of the composition are ramosetron and melatonin. The melatonin comprises a quick release part and a slow release part contained in cyclodextrin. The ramosetron composition for injection provided by the invention has the functions of improving the treatment effect of ranitidine, avoiding instability, fast distribution and elimination and the like of MT (Melatonin) caused by oral absorption, reducing the first pass effect of MT and reducing the dosage of ramosetron. Delivery design combining quick release and slow release meets the physiological secretion characteristic of MT, solves the problem of short half life of MT and improves the bioavailability of the product. The composition has a synergistic effect on treatment of CINV (Chemotherapy Induced Nausea And Vomiting) by ramosetron, and after the melatonin is combined with ramosetron, not only is the CINV treated, is the treatment effect of the ramosetron on the CINV improved and is the course of treatment shortened, but also the use level of the ramosetron and the side effect of the ramosetron are reduced, and the immunity of human body is improved. The melatonin in a certain concentration in human blood has the capability of effectively reducing melatonin of human body to the benefit of treatment of the CINV.

The present invention relates to the discovery that specific human taste receptors in the T2R taste receptor family respond to particular bitter ligands, i.e., acetaminophen, ranitidine, strychnine and denatonium. The present invention further relates to the use of these receptors in assays for identifying ligands that modulate the activation of these taste receptors and which may be used as additives in foods, beverages and medicinals for modifying (blocking) T2R-associated bitter taste.

A method for synthesizing ranitidine includes following steps: 1), dropwise adding sodium hydroxide water solution into 1, 1, 2-trichloroethane at 30-35 DEG C for reaction to obtain vinylidene chloride, wherein a mass ratio of 1, 1, 2-trichloroethan to sodium hydroxide is 1:0.3-0.33; 2), dropwise adding vinylidene chloride into mixed acid of concentrated hydrochloric acid and concentrated nitric acid at 20-25 DEG C for reaction for 2-4h, wherein a consumption ratio of vinylidene chloride to the mixed acid is 1:2-3; 3), adding cysteamine hydrochloride into sodium hydroxide and potassium hydroxide solution, and dropwise adding a product of the step 2) at 50-55 DEG C to obtain a closed-loop product; 4), enabling the closed-loop product to react with alcohol or methanol solution at room temperature for 14-18h to obtain an open-loop product; 5), adding the open-loop product and 2-[(dimethylamino)methyl]-5 chloromethyl-furan into potassium hydroxide or sodium hydroxide water solution for reaction at 40-50 DEG C for 2-4h to obtain ranitidine. The method lowers potential safety hazards and is simple and easy for industrial production.