INTRODUCTION:

Recently, the pharmaceutical industry has seen an increase in the use of oral controlled release drug delivery to achieve better therapeutic benefits such patient compliance, ease of dosage administration, and formulation flexibility¹. This is because the DF (dosage form) has a comparatively short transit time in these anatomical segments.

As a result, the drug is released in the short, non-absorbing distal section of the GIT after the CR-DF (controlled release DF) has already exited the upper GIT in less than six hours. As a result, there is a brief absorption phase followed by decreased bioavailability². The development of controlled drug delivery systems is the focus of the pharmaceutical industry today to obtain the necessary therapeutic concentration of the medication material with a lower dosage. Despite excellent progress in drug delivery, the oral method of administration³.

Goal: Many formulators are interested in these because of their benefits over the drug delivery methods, as of late⁴. The paper gives a broad overview of the most recent developments in this field and highlights these benefits in relation to the different kinds of gastroretentive drug delivery systems⁵. Floating control medication delivery is necessary⁶. New therapeutic compound development is costly and time-consuming. Various approaches have been tried to increase the safety-efficacy ratio of "old" medications, including customizing both therapeutic drug monitoring and pharmacological therapy⁷. Other highly appealing approaches that have been actively pursued include targeted delivery, slow delivery, and controlled rate delivery. To keep the concentration within the therapeutic range for medications with short half-lives and a definite link between concentration and response, frequent dosing will be needed⁸. Higher peak concentrations with potential harm will arise from higher dosages given less frequently. This method might work well for certain medications with broad safety margins⁹.

Floating Drug Delivery System:

Low-density systems with sufficient buoyancy to float over the contents of the stomach and stay buoyant in the stomach for an extended amount of time without influencing the gastric emptying rate are known as floating systems or hydrodynamical controlled systems¹⁰. As a result, the variations in plasma drug concentration are better controlled and the stomach retention period is extended¹¹.

For a medicine, a floating dosage form with a lengthy half-life in the stomach is essential.

1. In the stomach, that is locally active¹².

2. Possess an absorption window in the upper small intestine or stomach.

3. In the intestine or colonic environment, that is unstable.

Basic Physiology of the Gastrointestinal Tract:

Stomach: The stomach is located just beneath the diaphragm in the left upper section of the abdominal cavity¹³. Depending on the extent of distension, its size can range from 1500ml after a meal to a collapsed state with a resting capacity of 25 to 50ml (CitationWaugh & Grant, 2001). The fundus, body, and antrum (sometimes known as the pylorus) are the three anatomical components of the stomach¹⁴. While the distal region (antrum) is the primary location of mixing motions and functions as a pump to complete gastric emptying, the proximal stomach, which is composed of fundus and body regions, acts as a reservoir for the materials that have been consumed ¹⁵.

FDDS Without Effervescence:

Gel-forming or highly swellable cellulose type hydrocolloids, polysaccharides, and matrix-forming polymers like polycarbonate, polyacrylate, polymethacrylate, and polystyrene are the most often used excipients in non-effervescent FDDS¹⁶.

These dosage forms are buoyant due to the air trapped by the swollen polymer¹⁷. The hydrocolloid begins to hydrate by forming a gel when such DF comes into contact with an aqueous medium, regulating the rate at which the drug diffuses out of the DF and the solvent diffuses in¹⁸.

The gel layer is maintained by the immediate adjacent hydrocolloid layer being hydrated as the DF's external surface dissolves. Microparticles based on low-density foam powder are the foundation of the most recent FDDS technique¹⁹. This system's zero to very small lag time before floatation begins makes it advantageous²⁰.

FDDS With Effervescence:

These buoyant delivery systems make use of matrices made with effervescent ingredients like sodium bicarbonate and citric or tartaric acid32, as well as swellable polymers like Methocel or polysaccharides, such chitosan. A liquid that gasifies at body temperature makes up another system²¹. The matrices are constructed in such a way that CO2 is trapped in the gellified hydrocolloid and released by the stomach's acidity upon arrival. This keeps the dosage form buoyant and causes it to move upward²².

Floating drug delivery system application:

According to a recent study, administering Diltiazem floating tablets twice daily may be more effective than using regular pills for regulating hypertension patients' blood pressure²³. In patients with Parkinson's disease, HBS holding L-Dopa and benserazide maintained a significant plasma concentration during the course of 6–8 hours of absorption²⁴. Misoprostol is a synthetic prostaglandin analog found in CytotechR, which is used to prevent gastrointestinal ulcers brought on by non-steroidal anti-inflammatory medicines (NSAIDS)²⁵.

Formulation Relatives:

When creating new controlled release dosage forms, three crucial factors should be considered. Criteria, such as medication, delivery, and final destination²⁶.

Drug physiochemical characteristics can be studied with the aid of pre-formulation experiments. These characteristics include incompatibility, solubility, pH, and pKa²⁷.

Floating Drug Delivery System (FDDS) Components:

The following elements are utilized in the creation of FDDS

· Hydrocolloids: These are artificial, slightly altered cellulose derivatives that can be either nonionic or anionic, such as bentonite, agar, pectin, acacia, and gelatin²⁸.

· Polymers: The development of floating drug delivery mostly uses polymers such as HPMC K4M, HPMC K15M, HPMC K100M, polyethylene glycol, polycarbonate, sodium alginate, PVA, PVP, eudragit, carbopol, methyl methacrylate, and acrylic polymers²⁹.

· Effervescent Agent: When creating an effervescent-based floating formulation, a variety of substances are utilized as effervescent agents, including sodium bicarbonate, citric acid, tartaric acid, nitroglycerin, and di-sodium glycine carbonate³⁰.

· Inert Fatty Materials: By having a specific gravity below one, fatty materials lose their hydrophilic qualities and increase buoyancy.

For instance, mineral oil, long-chain alcohol, and beeswax³¹.

· Release Rate Modifier: Excipients such as lactose and mannitol can be used to alter the formulation's release rate³².

· Release Rate Retardants: They slow the release of medications by decreasing their solubility. For instance, magnesiumstearate, talc, and dicalcium³³.

· Buoyancy Increasing Agent: Ethyl cellulose and other materials with a low bulk density (lessthan one) can be employed to make the formulation more buoyant. Eighty percent of the weight might contain ³⁴.

Advantages:

The floating multi-particulate drug delivery method has the following benefits:

1. Increases patient compliance by lowering frequency of dosages³⁵.

2. Despite the first pass effect, bioavailability is improved because continuous drug release keeps a desired plasma drug concentration and prevents variations in drug concentration³⁶.

3. Buoyancy causes an increase in gastric retention time³⁷.

4. Improved absorption of medications that only dissolve in the stomach³⁸.

5. Extended periods of controlled drug releases³⁹.

6. It is possible to send drugs to the stomach at particular sites.

7. Better than floating dosage forms with a single unit, these microspheres release the medicine equally and eliminate the possibility of dose dumping.

8. Because of the continuous release action, stomach discomfort can be avoided.

9. Short half-life medications can have a better therapeutic effect.

Disadvantages:

One drawback of floating multi-particulate medication delivery devices is that their stomach residency period is dependent on based on the condition of digestion

1. Therefore, it is recommended that floating multi particulate medication delivery systems be used following a meal⁴⁰.

2. The dosage form's level of hydration determines its ability to float. A tumbler full of water should be administered every two hours to maintain the microsphere's buoyancy in vivo⁴¹.

3. The client must be positioned upright for the medication to stay in the stomach.

4. Drugs with stability or solubility issues in the stomach fluid are not appropriate for floating multi particulate drug delivery systems.

5. A medication such as nifedipine, which has a high first pass metabolism and is well absorbed throughout the GIT, might not be a good fit for floating multiparticulate drug delivery systems because of the potential for decreased systemic bioavailability due to the sluggish stomach emptying.

Methods for creating a floating drug delivery system:

Realistic methods for creating FDDS:

Davis (1968) introduced a technique to address the problem of gagging or choking that some people had after ingesting medication pills, which was the first written description of FDDS. The author proposed that a pill with a density of less than 1.0g/cm³ may be used to get around this problem and have the pill float on the water's surface. To create the perfect floating medication delivery system, a number of strategies have been employed since then (Moya Nakagawa et al. 2006). Methods for Creating Dosage Forms with One or More Units The design of floating dosage forms for single and multiple unit systems has been done using the following methodologies.

CONCLUSION:

One delivery method is the controlled release floating medication delivery system, which offers a possibility strategy for stomach retention. An overview of the factors influencing human stomach emptying is provided in this article, along with a discussion of the key ideas behind creating pharmaceutical dose forms with extended gastric retention times.

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Received on 07.11.2025 Revised on 04.12.2025

Accepted on 29.12.2025 Published on 13.04.2026

Available online from April 15, 2026

Asian J. Pharm. Tech. 2026; 16(2):182-186.

DOI: 10.52711/2231-5713.2026.00026

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