Trimethoprim and Sulphamethoxazole Tablets: Uses, Dosage, and Safety

Trimethoprim and sulphamethoxazole tablets, also known as co-trimoxazole or TMP-SMX, are a widely used combination antibiotic medication. They are commonly prescribed to treat various bacterial infections, including urinary tract infections, respiratory tract infections, and certain types of skin infections. This comprehensive guide aims to provide a detailed understanding of trimethoprim and sulphamethoxazole tablets, including their uses, dosage, potential side effects, and safety considerations. Whether you’re a patient or a healthcare professional, this guide will equip you with the knowledge needed to make informed decisions regarding trimethoprim and sulphamethoxazole tablet therapy.

Understanding Bacterial Infections

1.1 Types and Causes of Bacterial Infections

1.2 Common Bacterial Infection Symptoms

1.3 The Importance of Appropriate Antibiotic Treatment

Introduction to Trimethoprim and Sulphamethoxazole Tablets

2.1 What are Trimethoprim and Sulphamethoxazole Tablets?

2.2 Mechanism of Action

2.3 Available Brands and Forms of Trimethoprim and Sulphamethoxazole Tablets

Medical Uses of Trimethoprim and Sulphamethoxazole Tablets

3.1 Treatment of Urinary Tract Infections

3.2 Management of Respiratory Tract Infections

3.3 Skin and Soft Tissue Infections

3.4 Other Uses and Off-Label Applications

Dosage and Administration

4.1 Recommended Dosage for Different Infections

4.2 Dosage Forms and Strengths of Trimethoprim and Sulphamethoxazole Tablets

4.3 Administration Techniques and Instructions

4.4 Monitoring and Adjusting Dosage

Potential Side Effects and Precautions

5.1 Common Side Effects of Trimethoprim and Sulphamethoxazole Tablets

5.2 Rare but Serious Side Effects

5.3 Precautions and Contraindications

5.4 Drug Interactions with Trimethoprim and Sulphamethoxazole Tablets

Safety Considerations and Special Populations

6.1 Safety Guidelines for Pregnant and Breastfeeding Women

6.2 Use of Trimethoprim and Sulphamethoxazole Tablets in Pediatric Patients

6.3 Geriatric Considerations and Dosage Adjustments

6.4 Managing Trimethoprim and Sulphamethoxazole Tablets in Patients with Comorbidities

Monitoring and Management

7.1 Regular Check-ups and Laboratory Tests

7.2 Assessing Treatment Response and Adjusting Therapy

7.3 Adherence and Follow-up Recommendations

Dietary Considerations and Precautions

8.1 Proper Hydration and Urinary Health

8.2 Potential Interactions with Food and Beverages

8.3 Educating Patients about Medication and Food Interactions

Frequently Asked Questions about Trimethoprim and Sulphamethoxazole Tablets

9.1 Can Trimethoprim and Sulphamethoxazole Tablets Cure Bacterial Infections?

9.2 How Long Can Trimethoprim and Sulphamethoxazole Tablets Be Used?

9.3 Are Trimethoprim and Sulphamethoxazole Tablets Safe for Long-Term Use?

9.4 Can Trimethoprim and Sulphamethoxazole Tablets Be Used with Other Medications?

Emerging Trends and Future Directions

10.1 Antibiotic Stewardship and Rational Use of Trimethoprim and Sulphamethoxazole Tablets

10.2 Development of New Antibiotics and Combination Therapies

10.3 Public Health Initiatives and Bacterial Infection Prevention


Trimethoprim and sulphamethoxazole tablets are a commonly prescribed antibiotic combination that plays a crucial role in the treatment of various bacterial infections. By understanding their uses, dosage, potential side effects, and safety considerations, patients and healthcare professionals can make informed decisions regarding their therapy. Adherence to the recommended dosage, precautions, and regular monitoring are crucial for successful treatment outcomes. Additionally, promoting antibiotic stewardship and patient education about the rational use of antibiotics can contribute to reducing the emergence of antibiotic resistance. With this comprehensive guide, you are equipped with the knowledge needed to navigate the world of trimethoprim and sulphamethoxazole tablets confidently.


PURPOSE: This Master Formula is written to describe the formulae, manufacturing procedure, specifications, packing details of dosage form.

SCOPE: This procedure is performed and is applied during the manufacturing of dosage form.(drugs formulations)

RESPONSIBILITY / ACCOUNTABILITY: It is the responsibility of Manufacturing Chemist to follow and adhere to this SOP. The Production Pharmacist, QC/QA Manager are accountable for the strict adherence to the master formula.(drugs formulations)


  1. Master Copy: Manager Quality Assurance
  2. Copy No. 1: Production Pharmacist
  3. Copy No. 2: Manager Quality Control
  4. Copy No. 3:  Tablet Section 
GENERIC NAME: N. A. PACK SIZE:  60 x 20 x 10


Each uncoated Tablet contains:

Trimethoprim                       I.P.        160 mg

Sulphamethoxazole            I.P          800 mg






1 Steam Jacketed Starch Paste Preparation Tank  
2 Sifter Machine – I
3 Roto Cube Blender –I
4 Rapid Mixer Granulator
5 Multi Mill
6 Fluidized Bed Drier
7 Oscillating Granulator
8 Sifter Machine – II
9 Roto Cube Blender – II
10 Tablet Compression Machine 27 Stations
11 Dedusting Machine
12 Tablet Inspection Machine
13 Single Track Blister Packing Machine

RAW MATERIALS (drugs formulations):_

S.NO. INGREDIENTS STD Theoretical Quantity Req. Overages % Total Quantity Used
1. Aerosil B.P. 1.000 kg 1.000 kg
2. Micro Crystalline Cellulose Phosphate  B.P. 3.000 kg 3.000 kg
3. Magnesium Stearate I.P. 1.500 kg 1.5000 kg
4. Sodium Benzoate I.P 0.400 kg 0.400 kg
5. Sodium Starch Glyculate I.P. 1.000 kg 1.000 kg
6. Starch I.P. 5.000 kg 5.000 kg
7. Starch I.P. 5.000 kg 5.000 kg
8. Starch I.P. 5.000 kg 5.000 kg
9. Sulphamethoxazole I.P. 160.000 160.000 kg
10. Talcum I.P. 2.000 kg 2.000 kg
11. Trimethoprim I.P. 32.000 kg 32.000 kg


S.NO. NAME OF THE MATERIAL Theoretical Quantity Req. For


Total Quantity Used
1. 84 MM CLEAR PVC 13.000 13.000 KGS
3. CELLO TAPE 1.000 1.000 NOS
4 CORRUGATED BOXES     D – 17 8.333 8.333 NOS


3.000 3.000 KGS
6 UNIT CARTON – 20 X 10


500.000 2.000 502.000 NOS


Moisture content of powder should be less than 2.0 %.

Average weight of each Tablet is 1060 milligrams.

Weight Variation Limit for average weight of 20 tablets is +0%.

Friability limit for 10 Tablets is not more than 1.0 %.

Hardness of the Tablets varies between 2 –4 kg/cm2.

Disintegration time for each Tablet is not more than 15 minutes.

Mix the batch, compress and de-dust the tablets and also perform the primary packing of Tablets at temperature not more than 25


Theoretical Yield is 2.0 Lacs Tablets.

Expected Practical Yield is 2.0 Lacs + 2% Tablets.

Packing Details:

Use PVC 92 mm Clear and Aluminium foil for blister packing.

Blister Pack the inspected and De-dusted tablets by using Single Track Blister Packing Machine as per its SOP.

Put 20 strips each containing 10 tablets in each carton.

Seal each carton from both ends with cello tape.

Pack such 60 cartons in specified corrugated box D-17 to give a pack size of 60 x 20 x 10 tablets.

Seal the each corrugated box with adhesive tape and label it properly by affixing the specified label.

MANUFACTURING PROCESS (drugs formulations):

Preparation of Starch Paste:

Prepare the starch paste in the manner given below using Steam Jacketed Starch Paste Preparation Tank by operating it as per its SOP.

Dissolve 0.400 kgs of Sodium Benzoate in 1 Ltr of DM water and stir continuously.

Add 5.0 kgs of Starch in 5.0 Ltrs D.M. water and stir continuously to make smooth slurry.

Heat 44 Ltrs of water separately.

To the boiling water add the solution of Sodium Benzoate and starch slurry. Stir it continuously until smooth paste is formed.


Fit the mesh # 20 Stainless Steel Sieve on the Sifter-I as per its SOP, Sift the all ingredients through it and collect separately in Stainless Steel Container.


Blend the following ingredients using Roto Cube Blender by operating it as per its SOP for 20 minutes and collect in Stainless Steel Container.

  • 5.0 kgs of Starch
  • 3.0 kgs of M.C.C.P.
  • 16.0 kgs of Sulphamethoxazole
  • 32.0 kgs of Trimethoprim

Wet Granulation:

Mix the above blended ingredients with the Starch paste using Rapid Mixer Granulator by operating it as per its SOP , Add starch paste in such a manner by following the procedure given below so as to achieve proper wetting.

Divide the blended powder in six equal parts.

Divide the prepared starch paste in six equal parts.

Mix the one part of blended powder and starch paste together in Rapid Mixer Granulator.

Similarly mix the other parts in same manner.

Wet Screening:

Pass the wet dough through a Multi Mill by operating it as per its SOP to convert the moist mass into coarse, granular aggregates.


Dry the granules in Fluidized Bed Drier by operating it as per its SOP at temperature 600 – 700 C for 35 minutes. Cool the granules to room temperature.


Fit the mesh # 20 Stainless Steel Sieve on the Sifter-II as per its SOP, Sift all granules through it and collect in Stainless Steel Container. Break the oversized granules left over the mesh in Oscillating Granulator by operating it as per its SOP and resift them.

Check the total weight of dried granules. Determine the loss on drying and percentage yield of dried granules.


Lubricate the sifted granules along the following ingredients in a Roto Cube Blender by operating it as per its SOP  for 15 minutes and collect in Stainless Steel Container.

  • 1.0 kgs of Aerosil
  • 1.5 kgs of Magnesium Stearate
  • 5.0 kgs of Starch.
  • 2.0 kgs of Talcum.
  • 1.0 kgs of Sodium Starch Glycolate

Send the granules for bulk testing to Quality Control Department for assay of Active Ingredients.


Shift all the granules for compression to Tablet Compression Machine 27 Stations by operating it as per its SOP and collect the compressed tablets in Stainless Steel Containers.

Tablet Inspection:

Transfer the all tablets to tablet inspection machine and sort out the defected tablets by operating it as per its SOP  and collect the selected tablets in Stainless Steel Containers.

Blister Packing:

Shift the inspected tablets to blister section and blister pack them using Single Track Blister Packing Machine by operating it as per its SOP.

IN-PROCESS CONTROLS (drugs formulations): 

The following in-process controls should be maintained during the processing:

Check Raw materials used for manufacturing purpose are all approved materials and have ‘Released’ labels fixed on it.

All weighed Raw materials should be counter-checked by t Manufacturing Chemist. If any discrepancy is noticed, it should be immediately brought to the notice of Production Pharmacist and QC/QA Manager.

Physical characteristics of Raw material like colour, odour, and consistency are checked before compounding.

Humidity and temperature should be maintained during the compression of thermolabile products.

Sample of dried granules should be sent to Quality Control Department for the determination of Moisture content.

The total weight of blended powder should be checked in the presence of Assistant Manufacturing Chemist and record the same in Batch Manufacturing Record.

Bulk sample should be sent for analysis to Quality Control Department before starting compression of tablets.

Weight Variation: I) Intermittently weight variation of compressed tablets should be checked at 30 minutes interval by the Assistant Manufacturing Chemist and record for the same should be kept in Batch Manufacturing Record.

Out-of-limit tablets should be checked by Weight Variation Method as given below:

Take the average weight of 20 tablets on the calibrated balance and calculate the upper and lower limit as per the table given below in accordance with IP/BP:

                 (in mg)
80mg or less                                10
More than 80mg and less than 250mg                                 7.5
250mg or more                                  5

Take the weight of individual tablets and check if all the tablets are lying with in the limits.

Select the tablets only if no more than two tablets are out of percentage limit and if no tablet differs by more than two times the percentage limit, otherwise reject the tablets.

Adjust the desired weight of the tablets in the Compression Machine by moving weight adjustment cam clockwise or anticlockwise accordingly as per the Standard Operating Procedure of Compression Machine.

Re-check the weight of tablets for further adjustment, if any.

Thickness of Tablets:

Thickness of the tablets should be determined by means of the vernier caliper. The thickness of the tablet should be checked whenever weight adjustments are made.

Hardness of the tablets:

The equipment used is the ‘Monsanto’ type hardness tester. Hardness of the compressed tablets should be checked at regular interval to determine the need for pressure adjustments on the tableting machine.

Hardness of tablets varies between: 2-4 Kg/cm2.


‘Roche Friabilator’ is used for measuring the Friability. The instrument is designed to evaluate the ability of the tablet to withstand abrasion in packaging, handling and shipping.

Adjust the instrument to 25 RPM before adding the tablets.

Weigh 20 Tablets on calibrated balance. Transfer the tablets in the plastic chamber. Close the drum tightly.

Switch on the apparatus. Operate the Friabilator for 100 revolutions.

De-dust and reweigh the tablets. Loss in weight indicates the ability of tablets to withstand the wear.

Take 10 tablets to check the friability, when the average weight of tablet is 1g or more than 1g.

Friability Limit  = Less than 1.0%

Disintegration Test:

Disintegration is the time required for the group of tablets to disintegrate into the particles. Disintegration Test should be carried out at regular interval of 1 hour by using Disintegration Test Apparatus.

The tube assembly unit is removed from the glass beaker and from each tube the plastic discs are removed.

Place the tablets in each of 6 tubes along with a plastic disc over the tablets.

The glass beaker is filled with water. The water in the beaker is retained at the temperature of 37+1˚C through out the test by suitably setting the thermostat.

Introduce a tube assembly unit into glass beaker in such a way that wire mesh at the base of each tube is atleast 2.5cm below the surface of liquid when the basket is at highest position.

Switch on the apparatus to move the basket assembly containing the tablets up and down through a distance of 5 to 6 cm at a frequency of 28 to 32 cycles per minute. Start the stopwatch.

When the tablets have disintegrated i.e. when no particles remain on the wire mesh at the bottom of tube, stop the stopwatch. Note the time taken for disintegration of the tablets and record the same in Batch Manufacturing Record.

If one or two tablets fail to disintegrate, the test is to be repeated using 12 tablets.

Disintegration Time of uncoated tablets= Not more than 15 minutes

Disintegration Time of coated tablets= Not more than 30 minutes

Tablets taken for testing and In-process control should not be added to the bulk batch to avoid mix-ups and cross-contamination.

Inspection, sorting of rejected tablets should be done as per SOP.

The strips and cartons should be checked thoroughly for proper batch coding.

Manufacturing Chemist and Production Pharmacist should randomly check that the correct no. of strips are being packed in each cartons and also the number of cartons in each shipper is exactly the same as that shown in proof.

Intimation should be sent to Quality Control Department for finished product sampling and testing.

After the completion of labelling and packaging, the coded cartons should be accounted for and rejected printed material should be destroyed in the presence of QC/QA Manager. Fill the destruction sheet and attach the same in the Batch Manufacturing Record.

It will be ensure that filling or packaging equipment has been properly cleaned after the completion of batch.

Filling or packaging of next product should not commence until the IPQA has given the ‘Line Clearance’.