Pharmaceutical (and nutraceutical) products that are ingested, or applied topically to the body, e.g. to the skin, can be assessed for quality, efficacy and customer acceptance through texture analysis.
Medications to be chewed, crushed, broken apart or dissolved are required to break down easily to aid delivery/ingestion or dosage. These tablets, pills and capsule products must also be resilient enough to withstand transport, handling and packaging processes without breakage. The impact of formulation changes to facilitate the desired oral administration characteristics may be evaluated by repeatable testing and analysis methods. Providing preferable sensory qualities is a major benefit in products of this nature, as consumers often have an aversion to taking medication.
Lotions, ointments, creams and powders, which involve skin contact have many similarities to cosmetics, in terms of functional application - flow, spreadability, rate of absorption and ease of delivery. The texture affects finger feel, with smoothness and degree of oiliness influencing customer preference.
Test Methods for the Pharmaceutical Sector
Tablets can be evaluated for hardness and resistance to damage when being packaged or transported. The compressive force required to crush, or reduce to powder for ingestion within another carrier, for example to administer to a child or pet.
- Spreadability and ease of application of ointments and creams
- Forward extrusion, dispensing effort of creams and gels
- Used for semi-solids, forward or back extrusion can assess the characteristics of flow, consistency and spreadability, influnced by ingredient viscosity.
- Ensure consistent dispensing rates and forces for alternative formulations
- Spreadability and ease of application of moisturisers, hair waxes, masks and pastes (e.g. toothpaste)
- Forward extrusion, dispensing evaluation of creams, shampoos
- Solid tablets or lozenges can be tested for hardness with narrow diameter cylinder probes or needles.
- Tablet or lozenge hardness, bite force, crush resistance
- Rate of softening studies - throat lozenges dissolved in the mouth
- Cream, ointment stickiness
Some pharmaceutical and nutraceutical products include gelling agents in their formulations, as an alternative to creams of for the inherent properties of a gel. Gel industry standard tests for the raw ingredient or the final gel product, may be performed to evaluate the strength.
- Bloom strength testing