Abstract
Ayurveda, one of the oldest systems of medicine, presents a comprehensive approach to health and disease through the classical concept of Trisutra—Hetu (etiological factors), Linga (signs and symptoms), and Aushadha (therapeutics) Among these, Aushadha is not merely concerned with the selection of an appropriate medicine; its therapeutic potential is also closely linked with when, how, and under which physiological conditions it is administered. The classical concept of Aushadha Sevana Kala reflects this time-dependent approach to therapeutics, wherein the timing of medication is determined by factors such as Dosha predominance, Avastha of Agni, Rogi Bala, Roga Bala, Ahara, and the stage of disease. Acharya Vagbhata aptly emphasized the principle of “Kalo Bhaisajya Yoga,” highlighting the importance of selecting an appropriate time for drug administration to achieve the intended therapeutic outcome. Similarly, Acharya Charaka described that medicine administered at the appropriate time produces superior therapeutic effects compared with administration at an inappropriate time. Thus, Ayurveda appears to recognize that the efficacy of a medicine is influenced not only by what is administered, but also by when it is administered. This review explores the classical concept, classification, determinants, and therapeutic rationale of Aushadha Sevana Kala, with particular emphasis on its relationship with Ahara, Agni, Dosha, and disease condition. Furthermore, an attempt is made to examine its conceptual correlation with contemporary principles of drug absorption, bioavailability, pharmacokinetics, pharmacodynamics, and chronotherapy. Understanding this time-oriented therapeutic principle may provide a meaningful perspective toward individualized and rational drug administration in contemporary Ayurvedic practice. The review therefore aims to bridge the classical wisdom of Aushadha Sevana Kala with emerging concepts of time-dependent therapeutics and explore its potential relevance in modern clinical practice.
References
1. Bicker J, Alves G, Fortuna A, Falcão A. Timing in
drug absorption and disposition: The past, present, and
future of chronopharmacokinetics. British Journal of
Pharmacology. 2020;177(10):2215–2239.
doi:10.1111/bph.15017.
2. Agnivesha, Charaka. Charaka Samhita with
Vidyotini Hindi Commentary, edited by Kashinath
Pandey and Gorakhnath Chaturvedi. Vol. II. Chikitsa
Sthana, Yonivyapat Chikitsa, 30/296. Varanasi:
Chaukhambha Bharati Academy; Reprint 2025.
3. Sushruta. Sushruta Samhita, Uttara Tantra, 64/65–82.
Edited by Yadavji Trikamji Acharya. Varanasi:
Chaukhamba Orientalia; 2007
4. Tripathi B, editor. Ashtanga Hridayam of Vagbhata.
Sutra Sthana, Chapter 13, Verse 37. Delhi: Chaukhamba
Sanskrit Pratishtan; 2005. p.218.
5. Bicker J, Alves G, Fortuna A, Falcão A. Timing in
drug absorption and disposition: The past, present, and
future of chronopharmacokinetics. Br J Pharmacol.
2020;177(10):2215–2239. doi:10.1111/bph.15017.
6. Agnivesha, Charaka, Dridhabala. Charaka Samhita
with Ayurveda Dipika Commentary of
Chakrapanidatta.Chikitsasthana, Yonivyapat Chikitsa,
30/296–300. Varanasi: Chaukhambha Surbharati
Prakashan.
7. Bicker J, Alves G, Fortuna A, Falcão A. Timing in
drug absorption and disposition: The past, present, and
future of chronopharmacokinetics. Br J Pharmacol.
2020;177(10):2215–2239. doi:10.1111/bph.15017.
8. Kaur G, Phillips C, Wong K, Saini B. Timing is
important in medication administration: a timely review of
chronotherapy research. Int J Clin Pharm.
2013;35(3):344–358. doi:10.1007/s11096-013-9749-0.
9. Vagbhata. Ashtanga Hridaya with Sarvangasundara
Commentary of Arunadatta. Sutrasthana,
Dvividhopakrama Adhyaya, 13/37–41. Varanasi:
Chaukhambha Surbharati Prakashan.
10. Agnivesha, Charaka. Charaka Samhita with
Vidyotini Hindi Commentary, edited by Kashinath
Pandey and Gorakhnath Chaturvedi. Vol. II. Chikitsa
Sthana, Yonivyapat Chikitsa, 30/296. Varanasi:
Chaukhambha Bharati Academy; Reprint 2025.
11. Pandey, K., & Chaturvedi, G. (2025). Charaka
Samhita of Agnivesha with Vidyotini Hindi commentary
(Vol. 2, reprint ed.). Chaukhambha Bharati Academy.
12. Agnivesha, Charaka. Charaka Samhita with
Vidyotini Hindi Commentary, edited by Kashinath
Pandey and Gorakhnath Chaturvedi. Vol. II. Chikitsa
Sthana, Yonivyapat Chikitsa, 30/296. Varanasi:
Chaukhambha Bharati Academy; Reprint 2025.
13. Pandey, K., & Chaturvedi, G. (2025). Charaka
Saṃhitā of Agniveśa with Vidyotini Hindi commentary
(Vol. 2, reprint ed.). Chaukhambha Bharati Academy.
14. Agnivesha, Charaka, & Dridabala. (2014). Charaka
Samhita of Agnivesha, revised by Charaka and Dridabala,
with Ayurveda Dipika commentary of Chakrapani Datta
(Y. T. Acharya, Ed.). Chaukhamba Surbharati Prakashan.
15. Sushruta. (2007). Sushruta Samhita (Y. T. Acharya,
Ed.). Chaukhamba Orientalia.
16. Vagbhata. (2019). Ashtanga Hridaya (with
Sarvangasundara commentary of Arunadatta).
Chaukhamba Sanskrit Sansthan.
17. Sārṅgadhara. (2011). Śārṅgadhara Saṃhitā (S.
Srivastava, Hindi commentary). Chaukhambha Orientalia.
Pūrvakhaṇḍa, Chapter 2, Verses 2–3.18. Trikamji Y, editor. Charaka Samhita of Agnivesha
with Ayurveda Dipika Commentary of Chakrapani Datta.
Chikitsa Sthana, Chapter 30, verses 296–301. Varanasi:
Chaukhambha Orientalia.
19. Vaidya Yadavji Trikamji Acharya, editor. Sushruta
Samhita of Sushruta with Nibandha Sangraha
Commentary of Dalhana. Uttara Tantra, Chapter 64,
verses 65–67. Varanasi: Chaukhambha Orientalia.
20. Paradakara HS, editor. Ashtanga Hridaya of
Vagbhata with Sarvangasundara and Ayurveda Rasayana
Commentaries. Sutra Sthana, Chapter 13, verse 37.
Varanasi: Chaukhambha Surbharati Prakashan.
21. Shastri PP, editor. Sharangadhara Samhita with
Dipika and Gudartha Dipika Commentaries. Purva
Khanda, Chapter 2, verses 1–4. Varanasi: Chaukhambha
Surbharati Prakashana.
22. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana, edited by Yadavji Trikamji
Acharya. Uttara Tantra, Chapter 64, Verse 65. Varanasi:
Chaukhambha Orientalia.
23. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana, edited by Yadavji Trikamji
Acharya. Uttara Tantra, Chapter 64, Verses 66–67.
Varanasi: Chaukhambha Orientalia.
24. U.S. Food and Drug Administration. Food-Effect
Bioavailability and Fed Bioequivalence Studies: Guidance
for Industry. FDA; 2002
25. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana, edited by Yadavji Trikamji
Acharya. Uttara Tantra, Chapter 64, Verses 68–69.
Varanasi: Chaukhambha Oriental
26. Sushruta. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana. Uttara Tantra, Chapter 64,
Verses 73–74. Varanasi: Chaukhambha Orientalia.
27. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana. Uttara Tantra, Chapter 64, Verse
75. Varanasi: Chaukhambha Orientalia.
28. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana. Uttara Tantra, Chapter 64, Verse
77. Varanasi: Chaukhambha Orientalia.
29. Charaka Samhita with Ayurveda Dipika
Commentary of Chakrapani Datta, edited by Yadavji
Trikamji Acharya. Chikitsa Sthana, Chapter 30, Verse
300. Varanasi: Chaukhambha Orientalia.
30. Charaka Samhita with Ayurveda Dipika
Commentary of Chakrapani Datta, edited by Yadavji
Trikamji Acharya. Chikitsa Sthana, Chapter 30, Verse
300. Varanasi: Chaukhambha Orientalia.
31. Charaka. Samhita with Ayurveda Dipika
Commentary of Chakrapani Datta, edited by Yadavji
Trikamji Acharya. Chikitsa Sthana, Chapter 30, Verses
298–301. Varanasi: Chaukhambha Orientalia.
32. Charaka. Charaka Samhita with Ayurveda Dipika
Commentary of Chakrapani Datta. Chikitsa Sthana,
Chapter 30, Verses 297–301. Varanasi: Chaukhambha
Orientalia.
33. Sushruta. Sushruta Samhita with Nibandhasangraha
Commentary of Dalhana. Uttara Tantra, Chapter 64, Verse
65 onwards. Varanasi: Chaukhambha Orientalia.
