Procedure for Spreadability Testing in Semisolids

1) Purpose

The purpose of this SOP is to outline the procedure for testing the spreadability of semisolid pharmaceutical formulations to assess their ease of application and consistency.

2) Scope

This SOP applies to all semisolid formulations (e.g., creams, ointments, gels) manufactured within the facility that require spreadability testing as part of quality control.

3) Responsibilities

Quality Control (QC) Department: Responsible for conducting spreadability testing and ensuring compliance with this SOP.
Production Department: Responsible for providing semisolid samples and supporting QC during testing.

4) Procedure

4.1 Equipment Setup:
    4.1.1 Prepare a flat, smooth surface for testing (e.g., glass plate) cleaned and dried thoroughly.
    4.1.2 Ensure the room temperature and humidity are controlled to minimize environmental effects on testing.
    4.1.3 Calibrate any equipment used for measurement (e.g., ruler, stopwatch) according to validated procedures.

4.2 Sample Preparation:
    4.2.1 Obtain representative samples of semisolid formulations from different batches.
    4.2.2 Allow samples to equilibrate to room temperature before testing.
    4.2.3 Remove any air bubbles or surface irregularities from the sample surface.

4.3 Spreadability Testing:
    4.3.1 Place a specified amount of the semisolid sample onto the prepared surface.
    4.3.2 Use a standard weight or apparatus (e.g., spatula) to apply controlled pressure while spreading the sample.
    4.3.3 Measure the diameter of the spread area immediately after spreading and record the initial measurement.
    4.3.4 Allow the sample to remain undisturbed for a specified time (e.g., 30 seconds) to observe any changes in spread area.
    4.3.5 Measure the final diameter of the spread area after the specified time and record the measurement.

4.4 Calculation of Spreadability:
    4.4.1 Calculate the spreadability index using the formula: ( S = frac{{d^2}}{{t cdot w}} ), where:
        ( S ) = Spreadability index
        ( d ) = Diameter of spread area (mm)
        ( t ) = Time taken for spreading (seconds)
        ( w ) = Weight applied (g)
    4.4.2 Interpret the spreadability index to assess the ease of application and consistency of the semisolid formulation.
    4.4.3 Compare results against predefined acceptance criteria or pharmacopeial standards.

4.5 Documentation:
    4.5.1 Record all spreadability testing procedures, results, and observations in the Spreadability Testing Record.
    4.5.2 Maintain detailed records of sample details, testing conditions, equipment calibration, and any corrective actions taken.
    4.5.3 Review and approve the documentation by QC Manager.

5) Abbreviations, if any

QC: Quality Control

6) Documents, if any

Spreadability Testing Record
Equipment Calibration Certificates
Sampling Plan Document

7) Reference, if any

Pharmacopeial standards for Spreadability Testing in Semisolids
Internal specifications for Semisolid Formulations

8) SOP Version

Version 1.0