Anti–sunburn herbal formulations MCQs With Answer

Introduction: This quiz set on Anti–sunburn Herbal Formulations is designed for M. Pharm students preparing for the Herbal Cosmetics (MPG 204T) course. It focuses on mechanisms of UV‑induced skin damage, relevant phytochemicals, formulation strategies for sunburn prevention and relief, extraction and standardization approaches, safety considerations and analytical/evaluation methods (SPF, MED, photostability and phototoxicity). Questions are crafted to deepen understanding of how botanicals act as antioxidants, anti‑inflammatories or UV modulators, and how formulation design (delivery systems, excipients, encapsulation) and testing ensure efficacy and safety. Use these MCQs to test applied knowledge and support preparation for exams and formulation projects.

Q1. Which ultraviolet band is primarily responsible for causing sunburn (erythema) in human skin?

• UVC (100–280 nm)
• UVA (320–400 nm)
• UVB (280–320 nm)
• Visible light (400–700 nm)

Correct Answer: UVB (280–320 nm)

Q2. The Minimal Erythemal Dose (MED) is best defined as:

• The dose of UVA that causes tanning within 24 hours
• The lowest UV dose that produces perceptible redness on the skin 24 hours after exposure
• The UV dose that produces a sunburn in 50% of a population
• The dose of UV that photobleaches a dye in vitro

Correct Answer: The lowest UV dose that produces perceptible redness on the skin 24 hours after exposure

Q3. Which herbal constituent is most commonly used as a standard marker for evaluating Curcuma longa extracts in sunburn formulations?

• Epigallocatechin gallate (EGCG)
• Curcumin
• Silybin
• Glabridin

Correct Answer: Curcumin

Q4. Which antioxidant assay is frequently employed to screen herbal extracts for their free radical scavenging potential relevant to photoprotection?

• Papanicolaou stain
• DPPH radical scavenging assay
• Gram staining
• Rapid TLC spray test only

Correct Answer: DPPH radical scavenging assay

Q5. The Mansur in vitro method for estimating SPF from botanical extracts uses spectrophotometric readings primarily in which wavelength range?

• 250–280 nm
• 290–320 nm
• 320–380 nm
• 400–450 nm

Correct Answer: 290–320 nm

Q6. Which botanical is well documented for anti‑inflammatory and wound‑soothing activity in sunburn relief formulations?

• St. John’s wort (Hypericum perforatum)
• Aloe vera (Aloe barbadensis)
• Ruta graveolens
• Nerium oleander

Correct Answer: Aloe vera (Aloe barbadensis)

Q7. Which phytochemical class is primarily responsible for UV absorption and antioxidant action in many photoprotective herbs (e.g., green tea, grape seed, pomegranate)?

• Alkaloids
• Flavonoids and polyphenols
• Saponins only
• Essential amino acids

Correct Answer: Flavonoids and polyphenols

Q8. Curcumin provides photoprotective antioxidant benefits but has a major formulation challenge; what is it?

• High water solubility leading to wash‑off
• Severe systemic toxicity at topical doses
• Poor photostability and low skin penetration
• Becomes a strong UV absorber in visible range only

Correct Answer: Poor photostability and low skin penetration

Q9. Which in vitro test is recommended by OECD to evaluate phototoxic potential of chemicals and is applicable to herbal actives?

• 3T3 Neutral Red Uptake phototoxicity test (3T3 NRU)
• Ames bacterial reverse mutation test
• HET‑CAM irritation assay
• Patch test on human volunteers without control

Correct Answer: 3T3 Neutral Red Uptake phototoxicity test (3T3 NRU)

Q10. Which herb is known to contain photosensitizing compounds and therefore requires caution when used in sunburn formulations?

• Licorice (Glycyrrhiza glabra)
• St. John’s wort (Hypericum perforatum)
• Green tea (Camellia sinensis)
• Chamomile (Matricaria chamomilla)

Correct Answer: St. John’s wort (Hypericum perforatum)

Q11. For enhancing photostability and controlled release of herbal UV actives in a topical sunscreen, which formulation approach is most appropriate?

• Direct dissolution in aqueous gel only
• Encapsulation in liposomes or polymeric nanoparticles
• Mixing with surfactant solution without further processing
• Applying as dry powder without vehicle

Correct Answer: Encapsulation in liposomes or polymeric nanoparticles

Q12. Which evaluation parameter indicates broad spectrum UVA coverage in sunscreen testing?

• High SPF (only measures UVB protection)
• Critical wavelength ≥ 370 nm
• Low pH of formulation
• High viscosity of cream

Correct Answer: Critical wavelength ≥ 370 nm

Q13. When standardizing a photoprotective herbal extract rich in flavonoids, which chromatographic technique is commonly used for fingerprinting and quantification in M. Pharm research?

• HPLC or HPTLC fingerprinting
• Gel permeation chromatography only
• Paper chromatography exclusively
• Simple color comparison by eye

Correct Answer: HPLC or HPTLC fingerprinting

Q14. Combining botanical antioxidants with inorganic physical blockers (e.g., zinc oxide) in a sunscreen formulation mainly yields which benefit?

• Reduces SPF but increases scent
• Enhances oxidative protection and may improve photostability
• Makes the product water‑soluble only
• Eliminates need for preservatives completely

Correct Answer: Enhances oxidative protection and may improve photostability

Q15. Which extraction solvent is generally preferred to obtain a broad range of phenolic antioxidants from medicinal plants for sunburn formulations?

• Nonpolar hexane
• Hydroalcoholic (ethanol–water) solvent
• Pure acetone only
• Superheated steam exclusively

Correct Answer: Hydroalcoholic (ethanol–water) solvent

Q16. In topical anti‑sunburn herbal gels, which excipient attribute is most important to ensure patient comfort and non‑occlusion?

• High comedogenicity
• Non‑greasy, quick spreadability and appropriate viscosity
• Opaque, heavy waxy feel
• Strong acidic pH below 2

Correct Answer: Non‑greasy, quick spreadability and appropriate viscosity

Q17. Which herbal constituent is noted for inhibiting UV‑induced matrix metalloproteinases (MMPs) and aiding in photoprotection of skin collagen?

• Prostaglandin
• Epigallocatechin gallate (EGCG) from green tea
• Sodium lauryl sulfate
• Paraben preservatives

Correct Answer: Epigallocatechin gallate (EGCG) from green tea

Q18. During stability testing of an anti‑sunburn herbal cream, which parameter is most indicative of chemical degradation of the botanical active?

• Color change and decrease in assay of marker compound (e.g., curcumin content)
• Increase in pH to neutral only
• Change in container weight only
• Unchanged odor and color

Correct Answer: Color change and decrease in assay of marker compound (e.g., curcumin content)

Q19. Which in vivo measurement is used to determine the Sun Protection Factor (SPF) of a topical sunscreen product?

• Patch testing for sensitization only
• Ratio of MED of protected skin to MED of unprotected skin
• Measuring product viscosity under UV
• Determining the pH shift after UV exposure

Correct Answer: Ratio of MED of protected skin to MED of unprotected skin

Q20. Which safety concern must formulators particularly assess when adding skin‑penetration enhancers to herbal anti‑sunburn products?

• They always reduce SPF regardless of enhancer
• Increased systemic absorption of actives leading to potential phototoxicity or systemic exposure
• They convert all flavonoids to alkaloids
• They make the product colorless and odorless only

Correct Answer: Increased systemic absorption of actives leading to potential phototoxicity or systemic exposure

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