Design and Evaluation of Mucoadhesive Buccal Tablets of Loratadine Using Manila Tamarind Seed Powder

Govind Yadav*, Madhuri Dubey

Sarswati Higher Education & Technical College of Pharmacy, Dr. APJ Abdul Kalam Technical University, Lucknow.

*Correspondence: govindyadav20052000@gmail.com;

DOI: https://doi.org/10.71431/IJRPAS.2025.41010

INTRODUCTION

The oral route remains the most preferred drug administration pathway due to its simplicity, cost-effectiveness, and patient compliance [1, 2]. However, conventional oral drug delivery of drugs like Loratadine is limited by low solubility and significant first-pass hepatic metabolism, resulting in poor systemic availability [3, 4]. Buccal mucosa offers a rich vascular network and direct access to systemic circulation, thereby bypassing hepatic metabolism and enhancing bioavailability [5]. Mucoadhesive buccal tablets enable prolonged contact with the absorption site, improving residence time and drug permeation [6].

Mucoadhesion and Natural Polymers

Mucoadhesion refers to the attachment of a drug delivery system to the mucosal surface using synthetic or natural polymers. Recently, natural polymers have gained attention due to their biocompatibility, safety, biodegradability, and cost-effectiveness [7]. Pithecellobium dulce (Manila Tamarind) gum contains polysaccharides with excellent swelling and adhesive properties, making it suitable for mucoadhesive drug delivery [8].

Drug Profile and Need for Buccal Delivery

Loratadine, a second-generation antihistamine, is used for allergic rhinitis and urticaria. Its poor aqueous solubility and first-pass metabolism reduce its oral bioavailability to 40% [9]. Buccal delivery can overcome these limitations by enabling sustained release and improved absorption.

Aim of the Study

This research focuses on developing Loratadine mucoadhesive buccal tablets using P. dulce gum, evaluating their physicochemical characteristics, drug release profile, and stability.

Loratadine is limited by low solubility and significant first-pass hepatic metabolism, resulting in poor systemic availability [4]. Buccal mucosa offers a rich vascular network and direct access to systemic circulation, thereby bypassing hepatic metabolism and enhancing bioavailability [5]. Mucoadhesive buccal tablets enable prolonged contact with the absorption site, improving residence time and drug permeation [6].

Mucoadhesion refers to the attachment of a drug delivery system to the mucosal surface using synthetic or natural polymers. Recently, natural polymers have gained attention due to their biocompatibility, safety, biodegradability, and cost-effectiveness [7]. Pithecellobium dulce (Manila Tamarind) gum contains polysaccharides with excellent swelling and adhesive properties, making it suitable for mucoadhesive drug delivery [8].

Loratadine, a second-generation antihistamine, is used for allergic rhinitis and urticaria. Its poor aqueous solubility and first-pass metabolism reduce its oral bioavailability to 40% [9]. Buccal delivery can overcome these limitations by enabling sustained release and improved absorption. This research focuses on developing Loratadine mucoadhesive buccal tablets using P. dulce gum, evaluating their physicochemical characteristics, drug release profile, and stability.

MATERIALS AND METHODS

Study Design

The study was designed as an experimental formulation development project focused on designing Loratadine buccal tablets using a natural mucoadhesive polymer. Seven batches were formulated, characterized, and optimized based on physicochemical and mucoadhesive properties.

Materials

Loratadine was obtained as a gift sample from Cipla Ltd, Mumbai. P. dulce gum was isolated and purified in-house. MCC, ethyl cellulose, magnesium stearate, and talc were obtained from standard suppliers. All chemicals used were of analytical grade.

Equipment

The following instruments were used: single punch tablet compression machine, Monsanto hardness tester, Roche friabilator, Vernier caliper, analytical balance (±0.1 mg), UV–visible spectrophotometer (Shimadzu 1800), FTIR spectrophotometer (Shimadzu), and USP dissolution apparatus Type V.

Formulation Development

Seven formulations (F1–F7) were prepared using the direct compression method. Drug and excipients were accurately weighed, mixed uniformly, and compressed. The composition is presented in Table 1.

Table 1. Composition of Mucoadhesive Buccal Tablet Formulations (F1–F7)

Pre-compression Evaluation

Powder blends were evaluated for angle of repose (fixed funnel method), bulk and tapped density, Carr’s index, and Hausner’s ratio to assess flow properties.

Post-compression Evaluation

Tablets were evaluated for weight variation, thickness, hardness, friability, and drug content. Hardness was determined using Monsanto hardness tester, friability by Roche friabilator, and drug content by UV spectrophotometry at 249 nm.

Swelling Index and Mucoadhesive Strength

Swelling index was determined by weighing tablets before and after hydration in pH 6.8 phosphate buffer. Mucoadhesive strength was measured using a modified physical balance with porcine buccal mucosa as the model tissue.

In-vitro Drug Release

The dissolution test was performed using USP Type V apparatus in 900 mL pH 6.8 phosphate buffer at 37 ± 0.5 °C and 50 rpm. Samples were withdrawn at predetermined intervals, filtered, and analyzed at 249 nm.

Drug Release Kinetics

The release data were fitted to Zero-order, First-order, Higuchi, and Korsmeyer–Peppas models to determine the release mechanism.

FTIR Analysis

FTIR spectroscopy was performed to identify possible drug–polymer interactions.

Stability Study

Optimized batch F5 was subjected to stability studies at 40 ± 2 °C and 75 ± 5% RH for 90 days. Physical appearance, drug content, and drug release profile were analyzed at predetermined intervals.

RESULTS AND DISCUSSION

Pre-compression Parameters

All seven formulations (F1–F7) exhibited good flow properties, with angle of repose below 30°, Carr’s index values under 15%, and Hausner’s ratio below 1.2. These results indicate excellent flowability and compressibility of the powder blend, which is critical for uniform die filling during tableting.

Table 2. Pre-compression Parameters of Loratadine Mucoadhesive Buccal Tablets (F1–F7)

Post-compression Parameters

The prepared tablets were uniform in weight, thickness, and hardness. The hardness values were within 4–6 kg/cm², friability below 1%, and drug content between 97–99%. These results suggest good mechanical integrity and uniform drug distribution.

Table 3. Post-compression Parameters of Loratadine Mucoadhesive Buccal Tablets (F1–F7)

Swelling Index and Mucoadhesive Strength

Swelling index increased with increasing polymer concentration, peaking at F5. Excess polymer beyond F5 resulted in reduced swelling due to increased matrix density. Mucoadhesive strength also followed this trend, with F5 demonstrating the highest adhesion force.

Table 4. Swelling Index and Mucoadhesive Strength of Formulations

In-vitro Drug Release and Kinetic Modeling

The in vitro drug release study revealed sustained drug release over 08 hrs. F5 exhibited 98.16 ± 1.77% cumulative drug release. Kinetic analysis indicated the release followed the Korsmeyer–Peppas model with R² = 0.9872, signifying a non-Fickian diffusion mechanism.

Table 5. In-vitro Drug Release Profile of Optimized Batch (F1-F7)

Figure 1. In-vitro drug release profile of optimized formulation (F1-F7)

FTIR Studies

FTIR spectra of Loratadine, P. dulce gum, and the optimized formulation (F5) showedcharacteristic peaks corresponding to functional groups of Loratadine without major shifts, indicating no chemical interaction between drug and excipients.

Stability Studies

Stability studies of the optimized batch (F5) under accelerated conditions (40 ± 2 °C / 75 ± 5% RH) for 3 months showed no significant changes in drug content, appearance, or release profile, confirming formulation stability.

Table 6. Stability Study Data of Optimized Formulation (F5)

Figure 2. FTIR spectra of A. Loratadine, B. polymer, and C. optimized formulation (F5)

DISCUSSION

The results demonstrated that increasing polymer concentration enhanced mucoadhesive strength and swelling up to an optimum level (F5), beyond which excessive polymer concentration increased matrix viscosity and hindered drug diffusion. Formulation F5 displayed desirable physicochemical characteristics and sustained drug release. Drug release kinetics confirmed anomalous transport. FTIR confirmed compatibility, and stability results ensured product robustness for long-term use

CONCLUSION

This study successfully developed Loratadine mucoadhesive buccal tablets using P. dulce gum. The optimized formulation (F5) exhibited excellent mucoadhesive properties, swelling behavior, and sustained drug release over 8 hours. The natural gum proved to be a safe, effective, and economical mucoadhesive polymer. Buccal delivery of Loratadine using natural polymers can enhance bioavailability and patient compliance compared to conventional oral dosage forms.

REFERENCES

1. Patel VM, Prajapati BG, Patel MM. Mucoadhesive buccal drug delivery system: an overview. Indian J Pharm Sci. 2007; 69(4):460–467.
2. Shojaei AH. Buccal mucosa as a route for systemic drug delivery: a review. J Pharm Pharmaceut Sci. 1998; 1(1):15–30.
3. Bhatt D, Kumar M. Natural polymers in drug delivery systems. J Pharm Innov. 2020; 15(3):250–259.
4. Rang HP, Dale MM, Ritter JM, and Flower RJ. Pharmacology. 8th ed. Churchill Livingstone; 2016. p. 203–205.
5. Gandhi RB, Robinson JR. Oral cavity as a site for bioadhesive drug delivery. Adv Drug Deliv Rev. 1994; 13(1–2):43–74.
6. Andrews GP, Laverty TP, Jones DS. Mucoadhesive polymeric platforms for controlled drug delivery. Eur J Pharm Biopharm. 2009; 71(3):505–518.
7. Smart JD. The basics and underlying mechanisms of mucoadhesion. Adv Drug Deliv Rev. 2005; 57(11):1556–1568.
8. Singh K, Verma A. Manila tamarind gum as a natural mucoadhesive polymer. Int J Biol Macromol. 2021; 167:1344–1352.
9. Sweetman SC. Martindale: The Complete Drug Reference. 38th ed. Pharmaceutical Press; 2020. p. 1456–1457.
10. Vamshi VY, Chandrasekar K, Ramesh G. Development of mucoadhesive patches for buccal administration of carvedilol. Curr Drug Delivery 2007; 4:27–39.
11. Peddapalli H, Bakshi V, Boggula N. Formulation, in vitro and ex vivo characterization of mucoadhesive buccal tablets for an antihypertensive drug. Asian J Pharm Clin Res 2018; 11:402-11.
12. Balaji A, Radhika V, Goud V. Formulation and evaluation of mucoadhesive buccal tablets by using natural polymer. Int J Pharm Sci Res 2014; 5:4699-708.
13. Desai KG, Kumar TM. Preparation and evaluation of a novel buccal adhesive system. AAPS PharmSciTech 2004; 5:1-9.
14. Bhanja S, Ellaiah P, Mohanty C, Murthy KVR, Panigrahi B, Padhy S. Design and in vitro evaluation of mucoadhesive buccal tablets of perindopril prepared by sintering technique. Asian J Pharm Clin Res 2010; 3:1-10.
15. Charde S, Mudgal M, Kumar L, Saha R. Development and evaluation of buccoadhesive controlled-release tablets of lercanidipine. AAPS PharmSciTech 2008; 9:182–90.
16. Naga Rajau K, Velmurgan S, Deepika B, Sundar V. Formulation and in vitro evaluation of buccal tablets of metoprolol tartrate. Int J Pharm Pharm Sci 2011; 3:239-46.
17. Chinna Reddy P, Ramesh G, Shravan Y, Vamshi VY, Yamsani MR. Development of bioadhesive buccal tablets for felodipine and pioglitazone in combined dosage form: in vitro, ex vivo, and in vivo characterization. Drug Delivery 2011; 18:344–52.
18. Reddy KA, Venugopal K. Formulation and in-vitro evaluation of buccal tablets of piroxicam. Int J Chem Sci 2012; 10(1):399-412.
19. Inampudi A, Adimoolam S, Bhosale R, Vantoor BNS. Formulation and evaluation of vanlafaxine hydrochloride mucoadhesive buccal tablets. Int Res J Pharm 2012;3(1):226-31.
20. Barhate SD, Patel KM, Lokhande GS. Formulation and evaluation of buccoadhesive tablet of atenolol. Der Pharmacia Lettre 2011; 3(2):34-8.
21. Bhaskar U, Rudragouda P, Ravindra B, Swati M, Siddramesh B, Dhananjay A. Formulation and in-vitro evaluation of mucoadhesive buccal tablets of Furosemide. World J Pharm Pharm Sci 2012; 1(3):1041-63.
22. Chaudhari VA, Sarode SM, Sathe BS, Vadnere GP. Formulation and evaluation of mucoadhesive buccal tablet of Flurbiprofen. World J Pharm Pharma Sci 2014;3(5):945-62
23. Latheeshjlal L, Sunil A., Abdhul M, Vaidya MJ. Formulation and Development of Buccal Drug Delivery System containing Curcumin. Int J Pharm Tech Res 2011; 3(1):37-41.
24. Shivanand K, Raju SA, Nizamuddin S, Jayakar B. In-vivo bioavailability studies of sumatriptan succinate buccal tablets. DARU J Pharm Sci 2011;19(3):224-30.
25. Acholu PK, Yajaman S, Jayaveera KN. Ex-vivo and in-vivo evaluation of formulated novel felodipine core in cup buccal tablets. Asian J Biomed Pharm Sci2014;4(38):35-40.
26. Ceschel GC, Maffei P, Lombardi BS and Ronchi C. Design and evaluation of buccal adhesive hydrocortisone acetate (HCA) tablets. Drug Deliv. 2001; 8(3): 161 - 171.
27. Varshosaz J and Dehghan Z. Development and characterization of buccoadhesive nifedipine tablets. Eur J Pharm Biopharm. 2002; 54(2): 135 – 141