Assay Method of
Lactulose Solution
| Buffer | 1.15 gm sodium dihydrogen phosphate to 1000 ml water. |
| Ratio | Buffer : Acetonitrile = 15 : 85 |
| Diluents | Water : Acetonitrile = 50 : 50 |
| Standard | Take about 2 gm of Lactulose substance WS with 20 ml water (HPLC grade ) than add 25 ml acetonitrile then heat gently and cool finally make volume 50 ml with water (HPLC grade ) & mix well. Filter this solution with 0.45m membrane filter before injection. |
| Sample | Take sample about 2 gm of Lactulose substance with 20 ml water (HPLC grade ) than add 25 ml acetonitrile then heat gently and cool finally make volume 50 ml with water (HPLC grade) & mix well. Filter this solution with 0.45m membrane filter before injection. |
| Condition | Amino Bonded Column, 4.6 ´ 250mm./ Cell Temp.38º C / Oven Temp. 40º C /Refractive Index Detector / Flow Rate 1.4 ml per minute / Inject Volume 80 micro liter / Run Time 20 minutes / Retention Time 9 – 12 minutes. |
Assay Method of
Lansoprazole Capsule
| Solvent | Methanol |
| Standard | 50 mg ---® 100 ml ---® Take 1 ml ---® 50 ml |
| Sample | Same as standard. Take the absdrobance at 284 nm. |
Assay Method of
Leflunomide Tablet
| Solvent | Methanol |
| Standard | 50 mg ---® 100 ml ---® Take 1 ml ---® 50 ml |
| Sample | Same as standard. Take the absdrobance at 284 nm. |
Assay Method of
Lercanidipine HCl Tablet
| Solvent | Methanol |
| Standard | 25 mg ---® 50 ml ---® Take 5 ml ---® 50 ml (Shake 20 minutes) |
| Sample | Same as standard. Take the absdrobance at 355 nm. |
Assay Method of
Levamisole Hydrochloride Tablet
| Standard | Dissolve about 25 mg of Levamisole Hydrochloride in 60 ml of water and dilute to 100 ml with same solvent. |
| Sample | Shake a quantity of powder containing 25 mg of Levamisole Hydrochloride (1mg of Levamisole is equivalent to 1.178 mg of Levamisole Hydrochloride) with 60 ml of water for 20 minutes, add sufficient water to produce 100 ml and filter. |
| System | To 1 ml of each standard and sample preparation, add 0.5 ml of 6 % w/v sodium hydroxide and 1 ml of 5 % w/v nitroprusside solution, followed by 5 ml of 2.0 % w/v boric acid solution. Shake well and allow to stand for 2 minutes. Dilute to 10 ml with water. Measure the absorbance at 540 nm, against reagent blank , prepare in the same manner , using 1 ml of water. |
Assay Method of
Levofloxacin Tablet
| Solvent | Methanol |
| Standard | 50 mg ---® 100 ml ---® Take 1 ml ---® 100 ml (Shake 20 minutes) |
| Sample | Same as standard. Take the absdrobance at 226 nm. |
Assay Method of
Levofloxacin Solution
| Buffer | Add 3 ml Triethylamine in 1000 ml of water and adjust the pH to 3.2 with dilute Phosphoric acid. |
| Ratio | Buffer : Acetonitrile = 60 : 40 |
| Diluents | Buffer Solution |
| Standard | Take about 25.625 mg of Levofloxacin Hemihydrate WS equivalent to 25 mg of Levofloxacin in a 25 ml volumetric flask. Add 20 ml diluents and shake for 10 minutes and make the volume 25 ml with diluents and mix well. Dilute 2.5 ml to 50 ml with same diluents & mix well. Filter this solution with 0.45m membrane filter before injection. |
| Sample | Take 1ml solution equivalent to 25 mg of Levofloxacin in a 25ml volumetric flask. Add 20 ml of diluents and shake for 10 minutes & than make the volume 25 ml with diluents and mix well. Dilute 2.5 ml to 50 ml with same diluents & mix well. Filter this solution with 0.45 m membrane filter before injection. |
| Condition | Waters Spherisorb 10 mm ODS1 4.6 ´ 250mm./ 40º C / UV at 295 nm / 10 minutes. |
Assay Method of
Levosalbutamol Sulphate Tablet
| Buffer | Dissolve 2.50 gm of Potassium dihydrogen orthophosphate & 2.87 gm Sodium Heptane sulphonate with 950 ml distilled water into 1000 ml volumetric flask, adjust the pH 3.65 ± 0.05 with Phosphoric acid & make volume with distilled water up to 1000 ml. |
| Ratio | Buffer ( 78% ) : Acetonitrile ( 22% ) |
| Standard | Accurately weigh and transfer about 12 mg of working standard of Levosalbutamol Sulphate into 100 ml volumetric flask. Add 75 ml of mobile phase & shake for 20 minutes and dilute with mobile phase up to the mark and mix well. Filter this solution with 0.45 m membrane filter before injection. |
| Sample | Weigh and powder 20 Tablets. Take powder containing equivalent to 10 mg of Levosalbutamol into 100 ml volumetric flask. Add Add 75 ml of mobile phase & shake for 20 minutes and dilute with mobile phase up to the mark and mix well. Filter this solution with whatman filter paper & finally filter this solution with 0.45 m membrane filter before injection. |
| Condition | Waters Spherisorb C8 5.0 mm 4.6 x 150 mm / 30°C / UV at 220 nm / 10 minutes Levosalbutamol Sulphate : 3.5 minutes (approximately) |
Assay Method of
Levosalbutamol Sulphate Solution
| Standard | Accurately weigh and transfer about 60 mg of working standard of Levosalbutamol Sulphate INN equivalent 50 mg of Levosalbutamol into 50 ml volumetric flask. Add 35 ml of distilled water & shake for 10 minutes and dilute with distilled water up to the mark and mix well. Dilute 5 ml of this solution to 50 ml with distilled water. |
| Sample | Take 25 ml syrup equivalent to 5 mg of Levosalbutamol into 50 ml volumetric flask. Add 35 ml of distilled water & shake for 10 minutes and dilute with distilled water up to the mark and mix well Each mg of Levosalbutamol equivalent to 1.200 mg of Levosalbutamol Sulphate |
| Procedure | Take 5 ml of Standard & Sample solution each in two separate 25 ml volumetric flask. Add 5 ml of 1M Sodium carbonate solution & 0.5 ml of P-Amonophenol solution to each flask. Dilute to 25 ml with water. Keep at rest for 25 minutes. Measure the absorbance of the standard & sample solution at the maximum at 625 nm taking water as blank. |
Assay Method of
Lidocaine Hydrochloride Injection
| Sample | To a quantity of sample containing 0.100 g of Lidocaine Hydrochloride (10 ml ) add 10 ml of 2M sodium hydroxide. Mix. Extract two times each with 30 ml of chloroform. Wash each extract with the same 10 ml of water. Filter the washed extract through the filter paper moistened with chloroform. Wash the filter paper with 10 ml of chloroform. Evaporate the total chloroform extract to dryness. Dissolve the residue in 30 ml of glacial acetic acid. Add 6 ml of 5% w/v Mercury (II) acetate solution. Titrate with 0.1N perchloric acid using crystal violet solution as indicator. Each ml of 0.1N perchloric acid VS is equivalent to 27.082 mg of Lidocaine Hydrochloride. Calculation : Volume of VS in ml x Factor of VS x 27.083 X 100 / Weight of Lidocaine HCl in mg |
Assay Method of
Linzolid INN Raw Material
| Solvent | Methanol |
| Standard | 20 mg ---® 100 ml ---® Take 5 ml ---® 100 ml (Shake 20 minutes) |
| Sample | Same as standard. Take the absdrobance at 258 nm. |
Assay Method of
Loratadine Syrup
| Mobile Phase | Dissolve 1.74 g K2HPO4 in 500ml of water and make up to 1000ml with water. Mix three parts of this buffer with 8 parts of methanol. Adjust pH of this solution to 7.8 ± 0.1 with phosphoric acid . Filter through 0.45µ Filter and degass. |
| Standard | Weigh accurately about 50mg Loratadine WS and transfer in a 50 ml volumetric flask. Add 35 ml of Methanol Shake for 10 minutes and make the volume up to the mark (50 ml ) with methanol. Filter the solution and transfer 10ml of the filtrate in a 25ml volumetric flask. Make the volume up to the mark with Methanol and filter this solution with 0.45µ membrane filter before injection. |
| Sample | Shake Lora 60 ml Suspension for 30 minutes . Take 20 ml Suspension (equivalent to 20 mg of Loratadine) in a separating funnel. Add 30 ml chloroform to it and shake well for extraction. Separate the organic layer. Repeat the process. Combine the extracts and wash it with 15 ml distilled water. Take the extract in a conical flask and evaporate it on water bathe or rotary evaporator. Dissolve the residue with 20 ml methanol and then take in a 50 ml volumetric flask, make the volume up to the mark (50 ml) with Methanol & shake well. Filter the solution using Whatman filter paper at first and then filter through 0.45 µ membrane filter before injection. |
| Condition | µ- bondapaek C18, 250 x 46 mm, 5.0 µ pore size / Ambient / 254 nm / 25 minute / 20 µl |
Assay Method of
Loratadine + Pseudoephidrine Tablet
See ------àNext --------à Pseudoephidrine HCl + Loratadine Tablet
Assay Method of
Losartan Potassium Tablet
| Buffer | Dissolve 0.3854 g of Ammonium acetate in 1000 ml of water. |
| Ratio | Mix 50 volume of buffer & 0.1 volume of Triethylamine with 50 volume of acetonitrile, filter through a 0.45-micron membrane filter and degas. |
| Standard | Dissolve about 50.0 mg of Losartan Potassium WS in 70 ml of water and dilute to 100 ml with the same solvent. Dilute 5 ml to 25 ml with mobile phase. Filter this solution with 0.45 m membrane filter before injection. |
| Sample | Shake a quantity of the powdered sample containing about 50.0 mg of Losatran Potassium in 70 ml of water for 30 minutes, dilute to 100 ml with the same solvent and then filter. Dilute 5 ml filtrate to 25 ml with mobile phase. Filter this solution with 0.45 m membrane filter before injection. |
| Condition | C8 5.0 mm 4.6 x 250 mm / UV at 237 nm / 40 mL / 10 minutes |
Assay Method of
Losartan Potassium + Hydrochlorothiazide Tablet
| Buffer | Dissolve 385.4 mg of Ammonium acetate with 950 ml distilled water into 1000 ml volumetric flask & add 1 ml of Triethylamine & mix well. Adjust the pH 3.0 ± 0.05 with dilute Phosphoric acid & make volume with distilled water up to 1000 ml. |
| Ratio | Buffer ( 40% ) : Acetonitrile ( 60% ) |
| Standard | Accurately weigh and transfer about 50 mg of working standard of Losartan Potassium & 12.5 mg of Hydrochlorothiazide into 100 ml volumetric flask. Add 40 ml of water & shake for 10 minutes and dilute with methanol up to the mark and mix well. Then transfer 5 ml of this solution into 25 ml volumetric flask & volume up to the mark with mobile phase. Filter this solution with 0.45 m membrane filter before injection. |
| Sample | Weigh and powder 20 Tablets. Take powder containing equivalent to 50 mg of Losartan Potassium & 12.5 mg of Hydrochlorothiazide into 100 ml volumetric flask. Add 40 ml of water & shake for 10 minutes and dilute with methanol up to the mark and mix well. Filter this solution with Whatman filter paper. Further transfer 5 ml of this solution into 25 ml volumetric flask & volume up to he mark with mobile phase. Filter this solution with 0.45 m membrane filter before injection |
| Condition | C8 5.0 mm 4.6 x 250 mm / UV at 237 nm / 10 minutes Hydrochlorothiazide : 3.0 minutes & Losartan Potassium : 4.0 minutes (approximately) |
Assay Method of
Loperamide Hydrochloride Tablet
| Sample | Weigh and powder 50 capsules .Take powder equivalent to 55 mg of Loperamide Hydrochloride in a 250 ml iodine flask. Add 40 ml of chloroform , shake for 20 minutes . Filter . Evaporate the filtrate to dryness. Dissolve the residue in 30 ml of anhydrous glacial acetic acid. Add 6 ml of 5 % w/v Mercury (II) Acetate solution . Titrate with 0.1N perchloric acid VS using naptholbenzein solution as indicator.1 ml of 0.1N perchloric acid VS is º 51.35 mg of Loperamide Hydrochloride |
