SORBSAN Silver Flat

A wound that is both heavily exuding and critically colonised or infected presents a dual challenge: the exudate must be managed to prevent maceration of the surrounding skin and to keep the wound bed visible and assessable, while the microbial burden at the wound surface must be addressed to allow healing to proceed. A silver alginate dressing addresses both requirements simultaneously within a single wound contact layer. Sorbsan Silver Flat is a silver alginate dressing from Aspen Medical Europe combining calcium alginate exudate management with silver antimicrobial activity. Two sizes: 5cm x 5cm and 10cm x 10cm. Requires secondary dressing. No prescription required.

Sorbsan Silver Flat is a regulated medical device from Aspen Medical Europe. It is a flat pad wound contact dressing that combines calcium alginate fibres with silver to provide both gel forming exudate management and antimicrobial activity at the wound surface. The flat pad format is the same geometry as the standard Sorbsan Dressing, making Sorbsan Silver Flat the silver-enhanced version of the Sorbsan flat pad range.

The calcium alginate component of Sorbsan Silver Flat works through the same ion exchange mechanism as standard Sorbsan products. When wound exudate contacts the dressing, sodium ions from the exudate displace calcium ions from the alginate fibres, converting the dressing into a soft gel at the wound surface. This gel absorbs exudate, manages the wound fluid, and maintains a moist wound environment that supports the healing process. The haemostatic properties of the calcium alginate are retained in the silver version.

The silver component provides broad spectrum antimicrobial activity at the wound surface. When the alginate gels in contact with wound moisture, silver ions are released from the dressing into the wound environment. Silver ions disrupt bacterial cell walls and enzyme systems through multiple mechanisms, providing activity against a wide range of wound pathogens, including MRSA and other clinically significant organisms. This antimicrobial activity addresses the microbial burden at the wound surface during the dressing wear period.

Two sizes are available: 5cm x 5cm for smaller infected or critically colonised wounds, and 10cm x 10cm for medium wounds. Both require a secondary dressing to be applied over the Sorbsan Silver Flat to hold it in place and manage the exudate absorbed by the alginate.

Silver dressings should be used for a defined clinical period based on the signs of infection or critical colonisation that prompted their use. Review the wound at each dressing change. Discontinue Sorbsan Silver Flat and transition to standard Sorbsan Dressing or another appropriate dressing when the clinical signs that indicated antimicrobial treatment have resolved. Prolonged use of silver dressings without clinical review is not recommended.

Calcium Alginate Ion Exchange and Gel Formation

The calcium alginate fibres in Sorbsan Silver Flat absorb wound exudate through the same ion exchange mechanism as standard Sorbsan. Sodium ions from wound fluid displace calcium ions from the alginate fibres, forming a soft gel that absorbs exudate and maintains a moist wound environment. This gel forming process provides the exudate management function of the dressing and allows atraumatic removal at dressing change, as the gelled dressing does not adhere firmly to the wound surface.

Silver Ion Release and Antimicrobial Activity

Silver is incorporated into the Sorbsan Silver Flat dressing structure. When the dressing is moistened by wound exudate, silver ions are released from the dressing into the wound environment alongside the calcium ion exchange process. Silver ions act on bacteria through multiple pathways: they bind to bacterial cell membrane proteins and disrupt membrane integrity, interfere with bacterial respiratory enzyme systems, and bind to bacterial DNA. This multi-target mechanism provides broad spectrum antimicrobial activity and reduces the likelihood of bacterial resistance developing through a single resistance mutation.

Sustained Dual Action

The combined gel forming and silver ion release occurs progressively throughout the dressing wear period as exudate contacts the dressing. The alginate matrix provides a reservoir for both the calcium ion exchange and the silver ion release, supporting sustained dual activity during wear. This means the dressing addresses both the exudate management and the antimicrobial requirements of the wound throughout each wear period, not only at the moment of application.

Haemostatic Contribution

As with standard Sorbsan, the calcium ions released during the ion exchange process in Sorbsan Silver Flat participate in the coagulation cascade. The mild haemostatic effect at the wound surface may be useful in infected or critically colonised wounds that ooze at dressing change. This haemostatic property is a supplementary benefit of the calcium component alongside the primary gel forming and antimicrobial functions.

Wound Preparation

• Irrigate the wound with sterile saline before applying Sorbsan Silver Flat.
• Remove any loose debris or necrotic tissue.
• If the wound is dry, moisten the dressing with sterile saline before application to initiate gel formation.

Application

• Select the appropriate size to cover the wound surface.
• Apply the dressing directly to the wound bed with the silver alginate face in contact with the wound surface.
• Ensure the dressing covers the full wound area and extends slightly onto the surrounding skin margins.
• Apply an appropriate secondary dressing over the Sorbsan Silver Flat and secure in place.

Change Frequency and Review

• Change the dressing as dictated by exudate levels and the secondary dressing wear time.
• Review the wound at every change for signs of infection and healing progress.
• Assess whether continued use of the silver dressing is still clinically indicated at each change.
• Transition to standard Sorbsan Dressing when antimicrobial treatment is no longer required.

Removal

• If the dressing has not fully gelled, moisten with sterile saline before removal.
• Remove gently to avoid disrupting granulation tissue.
• Irrigate residual gel from the wound with sterile saline before applying a fresh dressing.

Sorbsan Silver Flat 5cm x 5cm

A small dressing for minor infected or critically colonised wounds and smaller ulcer surfaces. Suited to smaller surgical wounds with infection concern, small venous or pressure ulcers showing signs of critical colonisation, and wound sites where the wound bed is limited in extent.

Sorbsan Silver Flat 10cm x 10cm

A medium dressing for moderate wound sizes with infection or critical colonisation. Suited to venous leg ulcers, pressure ulcers, and diabetic foot wounds of moderate surface area where both antimicrobial activity and exudate management are required.

Both sizes contain the same silver alginate construction. Size selection should ensure the dressing covers the full wound surface.

When Not to Use Sorbsan Silver Flat

• Dry wounds with no exudate, where the gel forming mechanism cannot activate, and the dressing may adhere.
• Known sensitivity to silver or alginates.
• As a standalone dressing without a secondary dressing.

Precautions

• Always cover with an appropriate secondary dressing.
• Moisten with sterile saline before applying to dry wounds and before removal if not fully gelled.
• Review the clinical indication for silver dressing at each change.
• Discontinue when infection or critical colonisation signs have resolved.

Adverse Effects

• Silver related skin staining in some patients, typically superficial.
• Sensitivity reaction to silver or alginate components in susceptible individuals.
• Wound deterioration despite silver dressing use should prompt clinical reassessment.

Wounds Where Sorbsan Silver Flat Is Appropriate

• Critically colonised chronic wounds, including venous leg ulcers, pressure ulcers, and diabetic foot wounds where a high bacterial burden is impairing healing and exudate management is also required
• Infected wounds in conjunction with appropriate systemic antibiotic treatment, where a topical antimicrobial dressing is part of the wound management plan
• Surgical wounds with wound infection concern where both exudate absorption and antimicrobial activity at the wound contact layer are needed

Antimicrobial Stewardship

Antimicrobial dressings should be used when clinical signs indicate infection or critical colonisation and not as a routine preventive measure in all wounds. The decision to use Sorbsan Silver Flat should be based on clinical assessment of the wound, including signs such as increased pain, periwound erythema, heat, swelling, increased exudate, wound breakdown, or malodour. At each dressing change, the continued need for antimicrobial treatment should be assessed. When clinical signs have improved, transitioning to standard Sorbsan Dressing is appropriate.

Sorbsan Silver Flat vs Standard Sorbsan Dressing

Standard Sorbsan Dressing provides calcium alginate exudate management and gel forming properties for moderate to heavily exuding wounds without infection or critical colonisation. Sorbsan Silver Flat adds silver antimicrobial activity to the same alginate base, making it the appropriate choice when the wound assessment identifies infection or critical colonisation alongside high exudate. Use standard Sorbsan for clean exuding wounds. Use Sorbsan Silver Flat when antimicrobial activity is additionally required.

Sorbsan Silver Flat does not require a prescription. Both sizes are available from Pharmacy Planet without a clinical consultation.

Our pharmacists can advise on size selection and on when Sorbsan Silver Flat is appropriate compared with standard Sorbsan Dressing.

For deeply infected wounds, wounds not responding to silver dressing treatment, or wounds with signs of systemic infection, seek clinical assessment alongside purchase.

• Store in a cool, dry place away from direct heat and sunlight.
• Do not store above 25 degrees C.
• Keep in original sealed sterile packaging until immediately before use.
• Do not use if the packaging seal is broken.
• Check expiry date before use.
• Keep out of reach of children.

Pharmacy Planet is a GPhC registered online pharmacy. Both Sorbsan Silver Flat sizes are genuine Aspen Medical Europe products stocked through regulated UK supply chains.

Our pharmacists can advise on Sorbsan Silver Flat and on the full Sorbsan range for surface and cavity wound management with and without antimicrobial activity.

References

1. Aspen Medical Europe. Sorbsan Silver Flat — Product Information. Aspen Medical Europe. https://www.aspenmedicaleurope.com. Accessed June 2026.
2. National Institute for Health and Care Excellence. Wound care products: selection and prescribing. https://www.nice.org.uk. Accessed June 2026.
3. NHS. Wound infection: management and treatment. NHS England. https://www.england.nhs.uk. Accessed June 2026.
4. Wounds UK. Best Practice Statement: Antimicrobial stewardship in wound management. https://www.wounds-uk.com. Accessed June 2026.