A Comprehensive Review on Formulation and Evaluation of Sugar-Free Chewable Tablets using Natural Sweeteners

Abstract

The rising demand for sugar-free dosage forms has led to increased interest in developing chewable tablets for diabetic, pediatric, geriatric, and calorie-conscious patients (1,14). Chewable tablets should have an acceptable taste, disintegrate quickly, and feel good in the mouth while also ensuring stability and drug release (18,29). This review focuses on the formulation and evaluation of sugar-free chewable tablets made with natural sweeteners. Natural sweeteners like Stevia, Xylitol, Sorbitol, and Monk fruit provide benefits such as safety, dental protection, low glycaemic index, and enjoyable sweetness (9,10,15,39). The review discusses essential excipients, including binders, fillers, flavours ,disintegrants, and lubricants needed for optimal tablet design (20,11,24). It compares different formulation methods, such as direct compression and wet granulation (18,45). Key evaluation parameters include hardness, friability, weight variation, chewability, drug content, moisture analysis, taste masking, and stability studies (34,41,22). Recent findings suggest that natural sweeteners can effectively replace sugar without affecting the quality or acceptability of the product (5,19,21). However, there are still issues with taste masking and long-term stability (7,28,47). In summary, sugar-free chewable tablets promise broad therapeutic benefits and improved patient compliance (30,48).

Keywords

Introduction

Chewable tablets are a popular solid dosage form meant to be chewed before swallowing (1). They offer benefits like easy administration, better taste, and suitability for patients who struggle with swallowing regular tablets (14,18). Because of their pleasant taste and convenience, chewable tablets are especially preferred by children, the elderly, and bedridden patients (8,30).

Traditional chewable tablets often use large amounts of sugar to improve taste and mouthfeel. However, high sugar intake can lead to dental problems, weight gain, high calorie consumption, and other issues for diabetic patients (19,10,15). This concern has led to a growing demand for sugar-free chewable options that maintain taste without the negative effects of sugar. Natural sweeteners such as Stevia, Xylitol, Sorbitol, and Monk fruit are safe alternatives with low glycaemic indexes, better dental compatibility, and improved acceptability (9,10,15,39).

Creating sugar-free chewable tablets needs careful choice of excipients-binders, fillers, flavours, and disintegrants to achieve the right texture, chewability, and stability (18,20,11). It is also crucial to evaluate parameters like hardness, friability, disintegration, taste masking, and drug content to ensure product quality (29,34).

This review summarizes the strategies for formulation, natural sweeteners, excipients, and quality evaluation methods used in developing sugar-free chewable tablets, while also highlighting recent advancements and research gaps (14,49).

OVERVIEW OF CHEWABLE TABLETS

Chewable tablets are solid oral dosage forms meant to be chewed before swallowing (1,14). They must have a pleasant taste, smooth texture, and dissolve quickly in the mouth (18,26). These tablets are useful for children, elderly patients, and individuals who find it hard to swallow regular tablets (8,30). They improve patient compliance, allow for a faster onset of action, and enhance palatability (18,49).However, chewable tablets pose challenges such as effective taste masking, balancing hardness, and moisture stability (7,26,41). Successful formulation requires choosing excipients that balance strength and chewability (20,24).

NEED FOR SUGAR-FREE FORMULATION

Traditional chewable tablets often contain a significant amount of sucrose to enhance sweetness, but excessive sugar can lead to dental decay, high calorie intake, and unsuitability for diabetics (10,19,15). As lifestyle diseases rise, there is a strong need for sugar-free formulations that offer sweetness without negative health impacts (21,44).

Sugar-free tablets are ideal for diabetics, overweight individuals, and anyone concerned about dental health (10,44). Natural sweeteners provide a safer alternative, not elevating blood sugar levels and offering fewer calories while maintaining good taste (9,21,31).

NATURAL SWEETENERS USED IN CHEWABLE TABLETS

Stevia 

Stevia is a plant-based sweetener with very high sweetness and zero calories (9,21). It is stable at various temperatures and pH levels, though it may produce a slight bitter aftertaste, manageable with flavouring agents (31,47).

Xylitol

Xylitol is a sugar alcohol with a cooling effect and dental benefits (10,6,24). It prevents tooth decay by reducing bacterial growth. It also improves mouthfeel, making it ideal for chewable tablets.

Sorbitol

Sorbitol is non-cariogenic and serves as a sweetener and filler (15,17,32). It provides smooth texture and supports direct compression, popular in chewable formulations.

Monk Fruit Extract

A natural, calorie-free sweetener with strong sweetness and good stability (39). It does not impact blood glucose and has no aftertaste when blended with flavours (31,39).

Other Natural Agents

Thaumatin and honey powder are considered in some formulations depending on sweetness and compatibility (31,33).

EXCIPIENTS USED IN SUGAR-FREE CHEWABLE TABLETS

Successful formulation depends on proper excipient selection (29,20,24):

• Fillers: Mannitol, MCC, sorbitol (25,20,24)
• Binders: PVP K30, HPMC, starch paste (45,20)
• Disintegrants: Croscarmellose, cross-povidone, SSG (11,37)
• Lubricants: Magnesium stearate, talc (29,20)
• Flavors/Colours: Fruit flavours and mint for masking bitterness (7,43,48)

FORMULATION APPROACHES

1) Direct Compression

Used when materials have good flow and compressibility (20,18,38).

Steps:

1. Weighing of ingredients –Calculate and weigh drug + excipients
2. Blending –Mix API with diluents (e.g., MCC), lubricants (Mg stearate), glidants (talc).
3. Compression –Compress directly into tablets using a tablet compression machine.
4. De-dusting –Remove extra powder.
5. Packing –Blister or bottle packing.

2) Dry Granulation

For moisture- or heat-sensitive ingredients (45,29).

Steps:

1. Weighing and Mixing – Drug + excipients.
2. Slugging /Roller Compaction – Powder is compressed to form slugs or compact sheets.
3. Milling – Slugs/sheets are broken into granules.
4. Lubrication – Add lubricant + glidant.
5. Compression – Granules are compressed into tablets and De-dusting & Packing.

3) Wet Granulation

Used when powders have poor flow or compressibility (45,29,18).

Steps:

1. Weighing- Accurately weigh API + excipients.
2. Mixing- Dry mix drug + diluents + binder powders.
3. Preparation of Binder Solution- Binder dissolved in water or alcohol(e.g., PVP, starch paste).
4. Wet Massing- Add binder solution to powders to form a dough-like wet mass.
5. Screening- Pass the wet mass through a sieve to form wet granules.
6. Drying- Dry granules in tray dryer or fluidized bed dryer (FBD).
7. Sieving- Pass dried granules through sieve to get uniform size.
8. Lubrication- Add lubricants (Mg stearate), glidants (talc), disintegrants.
9. Compression- Compress using rotary tablet press.
10. Coating (Optional)- Film coating or sugar coating for taste, protection, colour.
11. Packaging- Protect tablets from moisture, breakage, contamination.

4) Co-processed Excipients

Provide better flow, compressibility, and mouthfeel (13,38).

Co-processed excipients are combinations of two or more excipients that are processed together (e.g., spray drying or granulation) to form a single, multifunctional excipient with improved flow, compressibility, and performance.

They are physically modified, not chemically changed, and are widely used in direct compression, chewable tablets, and ODT formulations.

EVALUATION PARAMETERS FOR SUGAR-FREE CHEWABLE TABLETS

Chewable tablets must undergo the following tests (29,34,41,22):

Hardness- Checks tablet strength. Chewable require moderate hardness to allow easy chewing. (34,29)

Friability- Measures weight loss during handling. Friability must be within acceptable limits to prevent breakage. (29)

Weight variation- Ensures uniform distribution of ingredients in each tablet. (29,34)

Thickness & diameter-  Check size uniformity for patient acceptability. (34)

Drug content - Ensures each tablet delivers the correct dose. (29,22)

Disintegration- Although chewable are chewed, they must also disintegrate

properly in the oral cavity. (11,34)

Chewability -  Assesses ease of chewing, texture, and mouthfeel. (26,49)

Moisture analysis-  Important for sugar alcohols that absorb moisture easily. (41,15)

Taste masking -  Ensures that bitterness or after test is minimized. (7,28,43)

Stability studies-  Performed under accelerated conditions to check physical and chemical stability. (22,41,47)

RECENT ADVANCES AND RESEARCH GAPS

Introduction of co-processed excipients for better chewability(13,38)

Development of herbal chewable tablets Improved taste-masking techniques Use of advanced analytical methods for stability testing(22,41)

Research Gaps

• Limited long-term stability studies on natural sweetener-based chewable tablets(47,35)
• Need for advanced flavouring systems to reduce bitterness
• Lack of data on interaction between natural sweeteners and active drugs(43)
• Few clinical acceptability studies in pediatric and geriatric groups(30,48)

CONCLUSION

Sugar-free chewable tablets are essential for diabetic, pediatric, geriatric, and calorie-conscious patients (14,44). Natural sweeteners such as Stevia, Xylitol, Sorbitol, and Monk fruit offer safe, effective alternatives to sugar (9,10,15,39). The success of these formulations depends on excipient selection for taste, mouthfeel, chewability, and stability (20,29,34).

Despite advancements in excipients, taste masking, and stability (7,28,13), challenges remain regarding long-term stability and flavour optimization (47,35,43). Continued research is needed to enhance patient acceptability and explore better combinations of natural sweeteners and excipients (42,49). Sugar-free chewable tablets hold strong potential for improved compliance and therapeutic outcomes, making this field important for future pharmaceutical development (18,48).

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