Research Article International Ayurvedic Medical Journal ISSN:2320 5091

PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGE- MENT OF MYOPIA 1Bende Yogita 2Sarika Choure 3Suraj Rathod 4Auti Swapnil S 1Asso. Professor, Dept of Panchkarma, Shri Mahavidyalaya, Nagpur. 2Assistant Professor, Dept. of Shalakya BM Ayurveda Mahavidyalaya, Nagpur. 3MD schlor. (Kayachikitsa) Govt. Ayurveda College and Hospital, Nagpur. 4Asst. Professor Dr. D.Y. Patil college of Ayurved and research centre, Pimpri, Pune.

ABSTRACT Nearsightedness, or myopia, is the most common refractive error of the eye, and it has be- come more prevalent in recent years. Nearsightedness can be corrected with glasses, contact lenses or refractive surgery. All these treatments are not much patient friendly and also not the actual solution to the pathology occurring in eye. Tarpana is one of the popular ocular therapies that is performed in Ayurveda and which is known to have a definite answer to the problem of Myopia. Thus it becomes necessary to explore the mode of action of Tarpana and give exact pharmacodynamics picture of the therapy so that its utility can be explained in sci- entific way. With this view an attempt was made to discover the scientific facts which can ascertain the Ayurvedic concepts. After a critical review of various researches, scientific texts and Ayurvedic classics it is concluded that Tarpana acts on the principle of Bahya Snehana. It can successfully cross the defensive barriers present in eye for absorption and nourishes the ocular and periocular structures, strengthens the sphincters & brings about changes in dioptric power and visual acuity. Key words: Tarpana, Myopia, nearsightedness, Snehana.

INTRODUCTION: World Health Organization's global initia- Eyes hold special status among all the tive for the elimination of avoidable blind- senses. Eyes are the most precious gift of ness by year 2020.3 Ayurvedic ocular ther- the God to the living beings. Good vision apies also known as Kriyakalpa are well is crucial for social and intellectual devel- known now a day in management of Myo- opment of a person. Recent data suggests pia which is considered as Timira in Ayur- that a large number of people are blind in veda. Among them also Tarpana is used different parts of the world due to high frequently and classical references also refractive errors especially myopia. Vari- justify the clinical utility of Tarpana in ous surveys in India have found the myo- management of Myopia. Thus an attempt pia prevalence ranging from 6.9% to has been made to elaborate the clinical 19.7%.1,2 Due to the significance of myo- utility in management of myopia & to pia as a global public health concern, it evaluate its pharmacodynamics in light of was chosen as a priority for Vision 2020, available scientific knowledge and under- How to cite this URL: Bende Yogita. Pharmacodynamics Of Tarpana And Its Utility In Management Of Myopia .International Ayurvedic medical Journal {online} 2016 {cited 2016 April} Available from: http://www.iamj.in/posts/images/upload/589_594.pdf 1Bende Yogita et;all: PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGEMENT OF MYOPIA standing of the ocular therapies. the anterior segment such as the iris and Ayurvedic concept of Tarpana: ciliary body (anterior uvea). Upon admin- The literary meaning of the Tarpana is to istration, precorneal factors and anatomical give nourishment to the eye through barriers negatively affect the bioavailabil- Ghruta, Ghruta Manda, medicated Ghruta, ity of topical formulations. Vasa, Majja, (bone marrow), etc. Pre-corneal factors include:8 Acharya Charaka in Sutrasthana Snehadh- • solution drainage, yaya explained that “Snehoanilam Hanti” • blinking, which means that Snehana is the supreme • tear film, 4 treatment for Vata Dosha. He mentioned • tear turn over, and Akshi - Tarpana as one of the 24 • induced lacrimation Snehapravicharana in Sutrasthana 13th Tear film, whose composition and amount 5 chapter. Ghruta is used primarily for Tar- are determinants of a healthy ocular sur- pana. Ghruta is effective in subsiding Pit- face, offers the first resistance due to its taja and Vataja disorders, it improves high turnover rate. Mucin present in the Dhatus and is overall booster for improv- tear film plays a protective role by forming 6 ing Ojas. The Ghruta has the quality of a hydrophilic layer that moves over the trespassing into minutest channels of the glycocalyx of the ocular surface and clears body. Hence when applied in the eye, it debris and pathogens.9 Human tear volume enters into deeper layer of Dhatus and is estimated to be 7 µl, and the cul-de-sac cleanses every minutest part of them. can transiently contain around 30 µl of the Moreover, Ghruta due to its San- administered ocular drug. However, tear sakaranuvartana quality easily imbibes the film displays a rapid restoration time of 2– properties of other drugs processed with it 3 min, and most of the topically adminis- 7 without leaving its own properties. Ghruta tered solutions are washed away within is also Sheeta Veerya, hence the eye being just 15–30 s after instillation. Considering the site of Alochaka Pitta can be effec- all the precorneal factors, contact time tively managed by constantly using with the absorptive membranes is lower, for Akshi Tarpana. Ghruta also contains which is considered to be the primary rea- properties like Balya, Brimhana and Ra- son for less than 5% of the applied dose , so it gives strength to the overall reaching the intraocular tissues.10 In case tissues of the eyeball as well as to the of Tarpana the volume of drug retained nervous tissues. over ocular surface is much higher in To provide nourishment the prerequisite is comparison to the eye drops thus mucin the absorption of drug through the ocular itself may get diluted by the Ghruta or any surface. But the eyes are supplied with va- other Tarpana drug removing the hydro- riety of defence mechanisms for protection philic layer barrier and provides more drug that offers the barrier in drug absorption. available for absorption. In addition, vari- Challenges in ocular drug delivery & ous layers of the cornea, conjunctiva, and Tarpana: Tarpana can also be considered sclera play an important role in drug per- as a route of ocular drug delivery through meation. The cornea, the anterior most topical administration. For most of the layer of the eye, is a mechanical barrier topically applied drugs, the site of action is which limits the entry of exogenous sub- usually different layers of the cornea, stances into the eye and protects the ocular conjunctiva, sclera, and the other tissues of tissues. It can be mainly divided into the 590 www.iamj.in IAMJ: Volume 4; Issue 04; March- 2016

1Bende Yogita et;all: PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGEMENT OF MYOPIA epithelium, stroma, and endothelium. Each delivery. It is vital to understand that the layer offers a different polarity and a po- permeant should have an amphipathic na- tential rate-limiting structure for drug per- ture in order to permeate through these meation. The corneal epithelium is lipoidal layers. Certain drugs used for Tarpana like in nature which contains 90% of the total Siddha Kshira are of this nature. Com- cells in the cornea and poses a significant pared to cornea, conjunctival drug absorp- resistance for permeation of topically ad- tion is considered to be nonproductive due ministered hydrophilic drugs. Furthermore, to the presence of conjunctival blood ca- superficial corneal epithelial cells are pillaries and lymphatics, which can cause joined to one another by desmosomes and significant drug loss into the systemic cir- are surrounded by ribbon-like tight junc- culation thereby lowering ocular bioavail- tional complexes (zonula occludens)11,12. ability. Conjunctival epithelial tight junc- Presence of these tight junctional com- tions can further retard passive movement plexes retards paracellular drug permeation of hydrophilic molecules.15 However, in from the tear film into intercellular spaces Tarpana the drug used is significantly in of the epithelium as well as inner layers of high dose that can give enough bioavaila- the cornea. Tarpana is mostly done with bility even after the loss in systemic cir- lipophilic drugs in the form of Ghruta, culation or in other words it can act both Vasa etc. thus it can be well absorbed locally and systemically. The sclera, which through lipoidal membrane and also it can is continuous with the cornea originates nourish this membrane so that its function from the limbus and extends posteriorly gets improved. Moreover, Tarpana is done throughout the remainder of the globe. The in lukewarm form that may dilate the tight sclera mainly consists of collagen fibers junctional complexes thus allowing para- and proteoglycans embedded in an extra- cellular drug permeation. The stroma, cellular matrix. Permeability through the which comprises 90% of the corneal sclera is considered to be comparable to thickness, is made up of an extracellular that of the corneal stroma. Recent reports matrix and consists of a lamellar indicate that the permeability of drug mol- arrangement of collagen fibrils. The highly ecules across the sclera is inversely pro- hydrated structure of the stroma poses a portional to the molecular radius.16 Tar- significant barrier to permeation of lipo- pana when did with Siddha Ghruta, it philic drug molecules. Endothelium is the contains more small chain fatty acids hav- innermost monolayer of hexagonal-shaped ing small molecular radius than the long cells. Even though endothelium is a sepa- chain fatty acids. Thus, they may get read- rating barrier between the stroma and ily absorbed. aqueous humor, it helps maintain the Pressure effect and refractive index: aqueous humor and corneal transparency Tarpana exerts extraocular pressure to the due to its selective carrier-mediated lens thus increasing its axial length. transport and secretory function.13 Fur- Though this pressure effect is transient but thermore, the corneal endothelial junctions due to the oleation and hydration provided are leaky and facilitate the passage of mac- by Tarpana may improve the accommoda- romolecules between the aqueous humor tion which can retain this pressure effect and stroma.14 Thus, corneal layers, partic- for longer duration. ularly the epithelium and stroma, are con- More contact time: Ghruta preparations sidered as major barriers for ocular drug used in Akshi-Tarpana are in the form of 591 www.iamj.in IAMJ: Volume 4; Issue 04; March- 2016

1Bende Yogita et;all: PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGEMENT OF MYOPIA suspension containing different particles of distances. It is a complex constellation of the drugs and the particles do not leave the sensory, neuromuscular and biophysical eye as quick as solution. Tissue contact phenomena by which the overall refracting time and bio availability is more hence power of the eye changes rapidly to image therapeutic concentration can be achieved objects at different viewing distances by Akshi – Tarpana. clearly on to the retina.17 Tarpana may act over accommodation capacity of eye by Accommodation and visual acuity: Ac- providing nutrition not only to the cornea commodation is the ability of the eye to but also to the sphincter muscles and change the refractive power of the lens to nerves innervating it. automatically focus on objects at various

Fig 1: changes in lens shape by accommodation for distant and close vision Nutritional supplement from Tarpana The dioptric power of the spherical lens drugs: Ghruta is used widely for Tarpana was reduced by 9 to 20 % in most of the which contains mainly omega-3 & 6 fatty researches. Durastha Darshana or acids, Vit A, E & K & antioxidants.18 Milk indistinct distant vision, is also used for Tarpana which contain va- Netrasrava, Netradaha , Netrayasa , riety of Vitamins, minerals, amino acids and Shirobhitapa were reduced statistically etc.19 significantly (P<0.001). clinical refraction, Review of researches to understand the for spherical lens, average improvement of clinical utility:20,21,22,23,24. 14-26 % can be achieved through Tar- Tarpana is used in Shalakya – a branch of pana. In old myopes also about 20% im- Ashtang Ayurveda to treat mainly Myopia. provements can be seen with Tarpana. Variety of Tarpana formulations have been Jeevantyadi Ghruta, Triphala Ghruta, Go- tried in various researches. Its clinical Ghruta, Ghrutamanda, Patoladi Ghruta utility can be understood by reviewing have been used in various researches. these researches. CONCLUSION: 592 www.iamj.in IAMJ: Volume 4; Issue 04; March- 2016

1Bende Yogita et;all: PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGEMENT OF MYOPIA After reviewing various researches and 10. Ahmed I. The noncorneal route in ocular available scientific data regarding Tarpana drug delivery. In: Mitra AK, editor. Oph- it can be concluded that, Tarpana is a supe- thalmic drug delivery systems. New York: rior therapy than merely using eye drops. Marcel Dekker; 2003. pp. 335–63 Tarpana acts on the principle of Bahya 11. Klyce SD, Crosson CE. Transport pro- cesses across the rabbit corneal epithe- Snehana. It can successfully cross the de- lium: a review. Curr Eye fensive barriers present in eye for absorp- Res.1985;4(4):323–31. doi: tion and nourishes the ocular and periocu- 10.3109/02713688509025145 lar structures & also strengthens the 12. McLaughlin BJ, Caldwell RB, Sasaki Y, sphincters. On virtue of drug utilised for Wood TO. Freeze-fracture quantitative Tarpana it also provides nutrition directly comparison of rabbit corneal epithelial and to the target organ. Changes in dioptric endothelial membranes. Curr Eye Res. power and visual acuity are evident hence 1985;4(9):951–61. doi: can be used for successful management of 10.3109/02713689509000002 myopia. 13. Barar J, Javadzadeh AR, Omidi Y. Ocular novel drug delivery: impacts of mem- branes and barriers. Expert Opin Drug REFERENCES: Deliv. 2008;5(5):567–81. doi: 1. Jain IS, Jain S, Mohan K. The epidemiol- 10.1517/17425247.5.5.567. ogy of high myopia-changing trends. In- 14. Sunkara GKU. Membrane transport pro- dian J Ophthalmol 1983;31:723-8 cesses in the eye. In: Mitra AK, editor. 2. Mohan M, Pakrasi S, Zutshi R. Myopia in Ophthalmic drug delivery systems. New India. ActaOphthalmolSuppl 1988;185:19- York: Marcel Dekker, Inc; 2003. pp. 13– 23. 58 3. McCarty CA, Taylor HR. Myopia and vi- 15. Saha P, Kim KJ, Lee VH. A primary cul- sion 2020. Am J Ophthalmol ture model of rabbit conjunctival epithelial 2000;129:525-7 cells exhibiting tight barrier properties. 4. Agnivesha, Charakasamhita. , Curr Eye Res. 1996;15(12):1163–9. doi: India: Chaukhamba Series; 2004. 10.3109/02713689608995151. Charaka Siddhisthana. 1/7, P 678 16. Geroski DH, Edelhauser HF. Transscleral 5. Agnivesha, Charakasamhita. Varanasi, drug delivery for posterior segment dis- India: Chaukhamba Sanskrit Series; 2004. ease. Adv Drug Deliv Rev. Charaka Sutrasthana. 13/25, P 83 2001;52(1):37–48. doi: 10.1016/S0169- 6. Agnivesha, Charak Samhita, Rashtrita 409X(01)00193-4. Sanskrita Sansthan, New delhi, reprint 17. Kaufman PL. Accommodation and 2006; sutrasthana13 / 14 Presbyopia: Neuromuscular and Biophysi- 7. Agnivesha, Charakasamhita. Varanasi, cal Aspects, in Hart WM, editors: Adler's India: Chaukhamba Sanskrit Series; 2004. Physiology of the eye: 9th Ed. St Louis: Charaka Sutrasthana. 13/13, P 82 CV Mosby; 1994. p. 391-411. 8. Ananthula HK, RD, Barot M, 18. https://en.wikipedia.org/wiki/Ghee#cite_n Mitra AK. Duane's Ophthalmology. In: ote-16 retrieved on 21 feb 2016 Tasman W, Jaeger EA, editors. Bioavaila- 19. https://en.wikipedia.org/wiki/Milk re- bility. Philadelphia: Lippincott Williams & trieved on 21 feb 2016 Wilkins; 2009 20. Durgesh Prasad Gupta1, Manjusha Ra- 9. Gipson IK, Argueso P. Role of mucins in jagopala2, Kartar Singh Dhiman A clini- the function of the corneal and conjuncti- cal study on Akshitarpana and combina- val epithelia. Int Rev Cytol. 2003;231:1– tion of Akshitarpana with Nasya therapy 49. doi: 10.1016/S0074-7696(03)31001-0.

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1Bende Yogita et;all: PHARMACODYNAMICS OF TARPANA AND ITS UTILITY IN MANAGEMENT OF MYOPIA in Timira with special reference to myopi- 24. Vinayaka Ashu, A clinical study on the aAYU, 2010;31:473-7. efficacy of Tarpana and Shatavaryadi 21. Poonam, R. Manjusha, D. B. Vaghela, and churna in the management of Timira w.s.r. V. J. Shukla A clinical study on the role of to Myopia. MD Thesis, IPGT & RA, Jam- Akshi Tarpana with Jeevantyadi Ghrita in nagar, 2004 Timira (Myopia) Ayu. 2011 Oct-Dec; Corresponding Author 32(4): 540–545 Dr. Yogita Bende 22. Poonam, R. Manjusha, D. B. Vaghela, and Asso. Professor, Dept of Panchkarma, V. J. Shukla A clinical study on the role of Shri Ayurveda Mahavidyalaya, Nagpur, Akshi Tarpana with Jeevantyadi Ghrita in Timira (Myopia) Ayu. 2011 Oct-Dec; Maharshtra, India 32(4): 540–545 Email: [email protected]

23. Manesh Kumar, a comparative study on Source of support: Nil the efficacy of Tarpana and Triphaladi Conflict of interest: None Declared drug compound in the management of Timira w.s.r. to myopia, MD Thesis, IPGT & RA, Jamnagar, 2003

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