Test methods for herbal cosmetics MCQs With Answer

Introduction

This collection of MCQs on “Test methods for herbal cosmetics” is tailored for M.Pharm students preparing for exams and practical evaluations in the Herbal Cosmetics (MPG 204T) syllabus. The questions focus on analytical, microbiological, physicochemical and regulatory test methods commonly applied to herbal cosmetic formulations — including stability testing, preservative efficacy, chromatographic fingerprinting, heavy metal and pesticide analysis, and physical characterization of topical products. These items reinforce conceptual understanding and encourage application of techniques used in quality control and regulatory compliance. Use these MCQs to identify knowledge gaps and sharpen test-preparation in laboratory-relevant topics for herbal cosmetic products.

Q1. Which primary objective best describes test methods applied to herbal cosmetic products?

• To maximize aesthetic appeal regardless of safety
• To ensure safety, quality, stability and intended performance
• To determine the cost-effectiveness of raw materials
• To replace clinical evaluation of product efficacy

Correct Answer: To ensure safety, quality, stability and intended performance

Q2. Which official USP chapter describes the Antimicrobial Effectiveness Test (preservative efficacy) commonly used for non-sterile topical products?

• USP Chapter 61
• USP Chapter 62
• USP Chapter 51
• USP Chapter 85

Correct Answer: USP Chapter 51

Q3. For low levels of water in lyophilized herbal extracts (<1% w/w), which analytical method gives the most accurate determination?

• Loss on drying (gravimetric)
• Karl Fischer titration
• TLC densitometry
• UV–Vis spectrophotometry

Correct Answer: Karl Fischer titration

Q4. Which chromatographic technique is most widely used for fingerprinting and semi-quantitative assay of multiple marker compounds in herbal cosmetic extracts?

• High performance thin layer chromatography (HPTLC)
• Paper chromatography
• Gel permeation chromatography
• Size exclusion chromatography

Correct Answer: High performance thin layer chromatography (HPTLC)

Q5. Which instrumental technique provides simultaneous multi-element analysis with the highest sensitivity for trace heavy metals in herbal cosmetics?

• Flame atomic absorption spectrometry (FAAS)
• Graphite furnace AAS (GFAAS)
• Inductively coupled plasma mass spectrometry (ICP-MS)
• UV–Vis spectrophotometry

Correct Answer: Inductively coupled plasma mass spectrometry (ICP-MS)

Q6. For detection of volatile pesticide residues in a plant-derived cosmetic ingredient, which analytical method is most appropriate?

• Gas chromatography–mass spectrometry (GC–MS)
• Infrared spectroscopy (FTIR)
• HPLC with UV detection
• Titrimetric assay

Correct Answer: Gas chromatography–mass spectrometry (GC–MS)

Q7. Which in vitro spectrophotometric method (popularized for sunscreens and some cosmetics) estimates SPF by measuring absorbance across UV wavelengths and applying a formula?

• Mansur spectrophotometric method
• Broadhurst–Smith method
• Karl Fischer method
• Folin–Ciocalteu method

Correct Answer: Mansur spectrophotometric method

Q8. Which test standard is commonly referenced for assessing antimicrobial protection (preservative efficacy) of cosmetic products in the European/International context?

• ISO 11930
• ICH Q1A
• USP 797
• EN 14214

Correct Answer: ISO 11930

Q9. Which technique is most suitable for qualitative identification of functional groups and major chemical classes in a crude herbal extract used for cosmetics?

• Fourier-transform infrared spectroscopy (FTIR)
• Thin layer chromatography (TLC)
• Particle size analysis by DLS
• Viscometry

Correct Answer: Fourier-transform infrared spectroscopy (FTIR)

Q10. Which assay is commonly used to screen antioxidant capacity of herbal extracts employed in cosmetic formulations?

• DPPH radical scavenging assay
• Bradford protein assay
• Titration with sodium thiosulfate
• Acid–base titration

Correct Answer: DPPH radical scavenging assay

Q11. Which instrument is most commonly used to measure the viscosity of creams and ointments in QC labs for herbal cosmetics?

• Brookfield viscometer
• Digital pH meter
• UV–Vis spectrophotometer
• Atomic force microscope

Correct Answer: Brookfield viscometer

Q12. For measurement of spreadability of a herbal cream in the laboratory, which simple method is routinely used?

• Parallel plate (slip) method
• Gas chromatography
• Karl Fischer titration
• Flame photometry

Correct Answer: Parallel plate (slip) method

Q13. Which light source is preferred for photostability testing of sunscreen and sun-protective cosmetics to simulate full-spectrum solar irradiation?

• Infrared lamp
• Xenon arc lamp
• Mercury vapor lamp
• LED white light

Correct Answer: Xenon arc lamp

Q14. Typical accelerated stability testing conditions used in many cosmetic stability studies are:

• 25°C/40% RH for six months
• 30°C/35% RH for three months
• 40°C ±2°C / 75% ±5% RH for three months
• 5°C ±3°C for two years

Correct Answer: 40°C ±2°C / 75% ±5% RH for three months

Q15. Which method is most appropriate for quantitative determination of residual solvents in herbal extracts intended for cosmetics?

• Headspace gas chromatography (HS–GC)
• FTIR absorbance at 1700 cm−1
• HPTLC densitometry
• Potentiometric titration

Correct Answer: Headspace gas chromatography (HS–GC)

Q16. Which microbiological test standard specifies methods for microbial enumeration (total aerobic count and total yeast & mold) relevant to non-sterile cosmetic products?

• USP 61 (Microbial Enumeration Tests)
• USP 1211 (Standard Solution Preparation)
• ICH Q3C (Residual Solvents)
• ISO 17025

Correct Answer: USP 61 (Microbial Enumeration Tests)

Q17. Which analytical approach is most appropriate for sensitive quantification of aflatoxins in herbal raw materials used in cosmetics?

• HPLC with fluorescence detection (HPLC–FLD) after derivatization
• Simple TLC with iodine staining
• UV–Vis spectrophotometry at 250 nm
• Gravimetric moisture analysis

Correct Answer: HPLC with fluorescence detection (HPLC–FLD) after derivatization

Q18. For characterization of nanostructured herbal cosmetic dispersions, which technique provides mean hydrodynamic particle size and polydispersity?

• Dynamic light scattering (DLS)
• Pendulum viscometry
• Gas chromatography
• HPLC–MS

Correct Answer: Dynamic light scattering (DLS)

Q19. Zeta potential measurement in nanoemulsions or nanoparticles primarily informs about which property relevant to product stability?

• Chelation capacity of metal ions
• Electrical surface charge and colloidal stability
• Antioxidant capacity
• pH of the medium

Correct Answer: Electrical surface charge and colloidal stability

Q20. Which analytical technique is most suitable for comprehensive profiling and identification of volatile and semi-volatile compounds in herbal fragrances or essential oils used in cosmetics?

• Gas chromatography–mass spectrometry (GC–MS)
• UV–Vis spectrophotometry
• Size exclusion chromatography
• Polarimetry

Correct Answer: Gas chromatography–mass spectrometry (GC–MS)

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