Formulation and Evaluation of Fast Dissolving Tablets of Telmisartan Using Natural excipients: A Comprehensive Review

Abstract

Hypertension is a chronic cardiovascular condition affecting a large proportion of the global population, leading to increased morbidity and mortality. Telmisartan, a selective angiotensin II receptor blocker, is frequently prescribed for its potent antihypertensive effects. However, conventional oral formulations of Telmisartan face challenges such as poor water solubility, slow dissolution rate, and delayed onset of action, which can negatively impact therapeutic efficacy and patient adherence. Fast dissolving tablets (FDTs) have emerged as a promising dosage form to address these limitations, providing rapid disintegration and immediate drug release without the need for water. The incorporation of natural superdisintegrants, derived from plant-based polymers such as guar gum, sodium alginate, and chitosan, has shown significant potential in enhancing disintegration and dissolution rates while offering advantages such as biocompatibility, biodegradability, and cost-effectiveness. This review provides a comprehensive analysis of Telmisartan FDTs, detailing natural excipient applications, formulation strategies, evaluation techniques, and stability considerations. The paper also highlights research gaps and future opportunities for developing more effective, patient-friendly, and sustainable oral drug delivery systems.

Keywords

Introduction

1.1 Hypertension and Global Prevalence

Hypertension is one of the most prevalent non-communicable diseases worldwide, contributing to the risk of heart failure, stroke, and kidney disorders. Epidemiological studies indicate that its prevalence is increasing, particularly in low- and middle-income countries. Managing hypertension effectively requires medications with reliable bioavailability and rapid therapeutic action.^[1]

1.2 Pharmacological Profile of Telmisartan

Telmisartan is an angiotensin II receptor blocker (ARB) that selectively inhibits the AT1 receptor, reducing vasoconstriction and aldosterone secretion. It is highly effective for long-term management of hypertension, with additional cardiovascular protective effects. ^[2]

1.3 Limitations of Conventional Telmisartan Tablets

Despite its efficacy, Telmisartan exhibits low aqueous solubility, leading to incomplete dissolution in the gastrointestinal tract. Conventional tablets may require water for swallowing, which is a limiting factor for elderly and pediatric patients. These issues necessitate the development of advanced oral dosage forms such as FDTs. ^[3]

1.4 Need for Fast Dissolving Tablet (FDT) Technology

FDTs are designed to disintegrate rapidly in the oral cavity, allowing immediate drug release and absorption. They enhance patient convenience, reduce first-pass metabolism, and can be particularly beneficial for drugs with poor solubility like Telmisartan. ^[4]

1.5 Role of Natural Excipients in Drug Delivery

Natural excipients derived from plants, such as guar gum, sodium alginate, and chitosan, have emerged as eco-friendly alternatives to synthetic superdisintegrants. Their ability to swell, absorb water, and facilitate rapid disintegration makes them valuable for improving the performance of FDTs. ^[5]

1.6 Objective of the Review

The primary aim of this review is to summarize recent advances in the formulation and evaluation of Telmisartan FDTs, with emphasis on natural superdisintegrants, formulation strategies, and evaluation methodologies, while highlighting future research directions. ^[6]

2. Telmisartan: Drug Profile

2.1 Chemical Structure and Properties

Telmisartan (C33H30N4O2) is a poorly water-soluble, BCS Class II drug. Its hydrophobic nature limits dissolution in aqueous environments, which can reduce oral bioavailability. ^[7]

 

 

 

Figure no.1. Telmisartan structure

2.2 Mechanism of Action

Telmisartan selectively blocks angiotensin II type 1 receptors, causing vasodilation, reduced blood pressure, and decreased cardiovascular strain. ^[8]

Renin Release (Kidney)

↓

Angiotensinogen → Angiotensin I

↓ (ACE)

Angiotensin II

↓

Binds to AT? Receptors

(Vascular smooth muscle, adrenal gland, heart, kidney)

↓

Vasoconstriction + Aldosterone Secretion + Na?/Water Retention

↓

↑ Blood Pressure

Figure no. 2. Mechanism of Action of Telmisartan

2.3 Pharmacokinetics and Bioavailability Issues

Telmisartan exhibits low oral bioavailability (~42–50%) due to poor solubility and limited gastrointestinal absorption. Enhancing dissolution is critical to achieve rapid therapeutic effect. ^[9]

2.4 Existing Conventional Formulations and Limitations

Traditional tablets and capsules are often associated with slow dissolution, patient non-compliance, and difficulty in administration for populations with swallowing disorders. FDTs present an ideal solution to these limitations. ^[10]

3. Fast Dissolving Tablets (FDTs)

3.1 Definition and Classification

FDTs are solid oral formulations that rapidly disintegrate in the mouth without water, releasing the drug for immediate absorption. Classification can be based on manufacturing techniques (direct compression, sublimation, freeze-drying) or disintegration mechanisms (swelling, wicking, effervescence). ^[12]

3.2 Advantages of FDTs

• Enhanced Patient Compliance: Easy to administer for pediatric, geriatric, and dysphagic patients. ^[13]
• Rapid Onset of Action: Fast disintegration improves therapeutic efficacy. ^[14]
• Enhanced Bioavailability: Particularly beneficial for poorly soluble drugs by promoting immediate dissolution. ^[15]

3.3 Mechanism of Tablet Disintegration

• Swelling: Superdisintegrants absorb water, expand, and physically break the tablet. ^[16]
• Wicking: Capillary action draws water into tablet pores, promoting rapid disintegration.
• Deformation: Hydration of polymer particles generates stress, facilitating tablet breakup. ^[17]

 

 

Figure no. 3. Mechanism of Tablet Disintegration

7. Challenges and Future Perspectives

7.1 Current Limitations in FDT Development

Despite the advantages of fast dissolving tablets (FDTs), several challenges remain. Poorly water-soluble drugs like Telmisartan still exhibit incomplete dissolution in some formulations, limiting bioavailability. Variability in mechanical strength, friability, and taste masking are additional hurdles. Moreover, natural excipients, while effective, may exhibit batch-to-batch variability due to differences in plant source, seasonal factors, and extraction methods. Addressing these limitations requires systematic optimization of formulation variables and robust quality control measures.

7.2 Regulatory Considerations for Natural Excipients

Regulatory acceptance of natural superdisintegrants is gradually increasing, but comprehensive safety and toxicological data are required for approval in new formulations. Differences in monographs, standardization challenges, and the need for reproducible physicochemical properties remain key concerns. Future regulatory frameworks may need to specifically address guidelines for plant-derived polymers in oral dosage forms.

7.3 Potential for Novel Natural Polymers

Emerging natural polymers from underutilized plant sources offer promising opportunities for FDTs. Polymers with high swelling capacity, improved hydrophilicity, and multifunctional properties can enhance tablet disintegration and drug dissolution. Nanostructured natural polymers or chemically modified derivatives may further optimize performance while retaining biocompatibility and biodegradability.

7.4 Scope for Combination Formulations and Multi-drug FDTs

FDTs can potentially be developed for combination therapy, allowing simultaneous delivery of multiple antihypertensive agents or co-administered drugs. Optimizing excipient compatibility and dissolution profiles in multi-drug FDTs could improve patient adherence and reduce pill burden. Such formulations require careful evaluation of drug–drug and drug–excipient interactions to ensure consistent release and stability.

7.5 Industrial Applications and Commercialization Potential

The simplicity and cost-effectiveness of FDTs make them attractive for industrial production. Natural superdisintegrants reduce dependency on synthetic excipients and appeal to the growing demand for green and sustainable pharmaceuticals. With advances in formulation technologies and regulatory acceptance, Telmisartan FDTs incorporating natural polymers have strong potential for commercialization in global markets, particularly for geriatric and pediatric populations.

CONCLUSION

This review highlights the significant role of natural superdisintegrants in the development of Telmisartan fast dissolving tablets. Literature evidence demonstrates that plant-derived polymers such as guar gum, sodium alginate, and chitosan effectively enhance disintegration and dissolution, addressing solubility and bioavailability challenges associated with conventional tablets. Fast dissolving tablet technology improves patient compliance, offers rapid onset of action, and reduces the need for water during administration. Future research should focus on the exploration of novel natural polymers, standardization of excipients, multi-drug FDT development, and systematic evaluation under regulatory guidelines to enable clinical translation and industrial adoption. The combination of sustainable natural excipients and optimized formulation strategies presents a promising pathway for enhancing oral drug delivery and therapeutic outcomes.

REFERENCES

1. Mills KT, Stefanescu A, He J. The global epidemiology of hypertension. Nat Rev Nephrol. 2020;16(4):223–237.
2. Zhou B, Perel P, Mensah GA, Ezzati M. Global epidemiology of hypertension: prevalence and risk factors. Lancet. 2021;398(10304):957–980.
3. Burnier M, Wuerzner G. Angiotensin II receptor blockers. Circulation. 2020;142(14):1326–1328.
4. Michel MC, Foster C, Brunner HR, Liu L. A systematic comparison of the properties of angiotensin II receptor antagonists. Pharmacol Rev. 2013;65(2):809–848.
5. Kakumanu VK, Arora V, Bansal AK. Role of excipients in enhancing oral bioavailability of poorly soluble drugs. AAPS PharmSciTech. 2011;12(3):846–859.
6. Gupta DK, Bajpai M, Chatterjee DP. Fast dissolving tablets: a review. J Pharm Sci Technol. 2010;2(1):112–121.

7. Shanmugam S, Vetrichelvan T. Solubility enhancement of Telmisartan by solid dispersion technique. Int J Pharm Sci Rev Res. 2010;5(2):55–60.
8. Patel DM, Patel MM. Optimization of Telmisartan formulation by solid dispersion. Int J Pharm Investig. 2012;2(3):132–137.
9. Vaidya S, Gangwal S. Enhancement of dissolution rate of Telmisartan using liquisolid compacts. Powder Technol. 2010;202(1–3):161–166.
10. Baviskar DT, Sharma V, Jain DK. Enhancement of solubility of Telmisartan by inclusion complexation. Int J Pharm Sci Drug Res. 2011;3(2):147–152.
11. Sweetman SC. Martindale: The Complete Drug Reference. 36th ed. London: Pharmaceutical Press; 2009.

12. Fu Y, Yang S, Jeong SH, Kimura S, Park K. Orally fast disintegrating tablets: developments, technologies, taste-masking and clinical studies. Crit Rev Ther Drug Carrier Syst. 2004;21(6):433–476.
13. Chang RK, Guo X, Burnside BA, Couch RA. Fast-dissolving tablets. Pharm Technol. 2000;24(6):52–58.
14. Seager H. Drug-delivery products and the Zydis fast-dissolving dosage form. J Pharm Pharmacol. 1998;50(4):375–382.
15. Kuchekar BS, Arumugam V. Fast dissolving tablets. Indian J Pharm Educ. 2001;35(4):150–152.
16. Dobetti L. Fast-melting tablets: developments and technologies. Pharm Technol Eur. 2001;13(6):44–50.
17. Bi Y, Sunada H, Yonezawa Y, Danjo K. Preparation and evaluation of compressed tablets rapidly disintegrating in oral cavity. Chem Pharm Bull. 1996;44(11):2121–2127.

18. Gohel MC, Parikh RK, Brahmbhatt BK, Shah AR. Preparation and assessment of novel coprocessed superdisintegrant. Int J Pharm. 2007;340(1–2):66–73.
19. Deshmukh VN. Mouth dissolving tablets: superdisintegrants and formulation. J Pharm Res. 2012;5(3):1588–1592.
20. Setty CM, Prasad DVK, Gupta VRM, Sa B. Development of fast disintegrating tablets using natural superdisintegrants. Int J Pharm Sci Nanotechnol. 2008;1(2):109–114.
21. Malviya R, Srivastava P, Bansal M, Sharma PK. Formulation and evaluation of fast dissolving tablets using guar gum. Int J Pharm Sci Res. 2010;1(9):72–78.
22. Nayak AK, Pal D. Natural polysaccharides as superdisintegrants in tablet formulations. J Appl Pharm Sci. 2011;1(9):11–28.
23. Reddy LH, Murthy RSR. Natural polymers in drug delivery. Indian J Pharm Sci. 2004;66(6):747–758.

24. Lachman L, Lieberman HA, Kanig JL. The Theory and Practice of Industrial Pharmacy. 3rd ed. Mumbai: Varghese Publishing House; 1987.
25. Aulton ME, Taylor KMG. Aulton’s Pharmaceutics: The Design and Manufacture of Medicines. 5th ed. Elsevier; 2018.
26. Thakkar VT, Shah PA, Soni TG, Parmar MY, Gohel MC. Development of directly compressible fast dissolving tablets. J Pharm Bioallied Sci. 2009;1(2):98–104.
27. ICH Q8(R2). Pharmaceutical Development. International Council for Harmonisation; 2009.

28. United States Pharmacopeia 43–NF 38. Rockville, MD: United States Pharmacopeial Convention; 2020.
29. ICH Q1A(R2). Stability Testing of New Drug Substances and Products. International Council for Harmonisation; 2003.
30. Banker GS, Anderson NR. Tablets. In: Lachman L, Lieberman HA, Kanig JL, editors. The Theory and Practice of Industrial Pharmacy. 3rd ed. Mumbai: Varghese Publishing House; 1987. p. 293–345.