Introduction of Pharmaceutical

Form development of pharmaceutical dosage is the mix of science and art with the aim of producing a dosage which is economical, stable, patient-friendly, efficacious, and capable of delivering drug with minimal negative effects to intended targets. In several cases, conventional forms of administration of drug have been supplanted by advancement in delivery systems of a novel drug. Pharmaceutical organizations are finding innovative forms of dosage by the way of competent delivery systems since a strategic tool is represented by them for expanding indications and markets, creating new opportunities, and extending life cycles of products.

When it comes to the delivery of drugs to the body, the most preferred and convenient route is oral administration. In spite of the immense advancement in the delivery of drugs to present period from the 90s, the most preferred route is oral to systemic circulation because of flexible formulation, patient compliance, and cheap drug cost. The oral route is used for administering almost ninety percent of overall drugs utilized for producing systemic effects. Out of drugs which are orally administered, solid forms of oral dosage represent the most preferable and convenient according to the acceptance of patients.

In contemporary use, the most common kind of dosage in the form of solid are tablets. They are classified on the basis of patterns of drug release, i.e., modifier release and conventional instant release. The form of pharmaceutical dosage is a tablet. It seems to comprise a combination of excitements and active substances, normally in the form of power, consolidated or compacted in solid dose from powder. Lubricants, glints, granulating agents or binders, and diluent can be included in excitements for efficient tab letting. Meanwhile, disintegrates are utilized for promoting break-up of tablet in the digestive tract; pigments for making them attractive visually; and flavors or sweeteners for enhancing the taste. Often, a polymer coating is applied for making the tablet easier and smoother to swallow, for controlling active ingredient’s release rate, for making it resistant to the surrounding environment, or for enhancing the appearance of tablet [1]. Tablets with an immediate release have several side-effects including release of an uncertain drug. But specific sites are used for absorbing many drugs, and they need a release at only that site for efficient absorption. Drug delivery with sustained release and controlled release have been gaining a lot of attention in the pharmaceutical field for achieving better therapeutic benefits like simple and flexible formulation, patient compliance, and simplicity of dose administration. It should be ensured that design of a DDS or drug delivery system which is orally controlled is aimed at obtaining increased and predictable drug bio availability. But the process of development is prevented by various psychological factors like the inability of localizing and restraining DDS within some specific areas of GI or gastrointestinal tract, and variable nature of the process of gastric release. Actually, it can be predicted that, according to the psychological state of patient and pharmaceutical formulation design, the process of emptying can last to 12th from only a few minutes. In turn, this variability might lead to times and unpredictable bio availability for achieving peak levels of plasma, as most of the drugs are absorbed in small intestine’s upper part. In addition, the transit time of small intestine is a significant parameter for medicines which are absorbed incompletely. Fundamental physiology of human with a description of motility patterns, gastric emptying, and gastric emptying being influenced by formulation variables are summarized. Retentive systems of gastropod can remain in the region for a long time and prolong the time of drugs in terms of gastric residence. Improvement in this retention promotes bio availability, decreases waste of drugs, and enhances solubility for less soluble drugs in the environment of high pH. Local delivery of drugs to small intestine and stomach are also affected by it. In fact, Castro retention assists in providing availability of innovative products, substantial benefits, and therapeutic possibilities for patients. Gastric retention in the form of solid dosage might be obtained by processes of modified shape, expansion, sedimentation, flotation, and adhesion due to which gastric emptying is delayed. Classification of FADS or delivery system of floating drug has been explained on the basis of these approaches [2].

DDS or Stomach specific drug delivery systems

Actually, drugs which have less half-lives and are absorbed easily from GIT or gastrointestinal tract are quickly eliminated from systemic circulation. For achieving a stable therapeutic activity, frequent drug dosing is required. For avoiding this limitation, production of oral controlled-sustained release is an attempt for releasing drugs slowly in gastrointestinal tract and maintaining an effective concentration of drug for a long time in systemic circulation. Such delivery of drug after oral administration would be kept in the stomach while releasing it in a controlled manner. This way, drug can be continuously supplied to absorption sites. Hence, a system should be designed, which enables longer residence, which will increase the time within which absorption of drug can take place in the small intestine. For formulating a site-specific dosage form which is orally administered and release is controlled, it is significant to obtain a prolonged residence duration by the DDS. Whereas DDS is a better system in which drug retention is prolonged to several hours. Conventional SS DDS's quick gastrointestinal transit can prevent the release of drug at the gastric region and efficacy reduction of administered drugs as stomach absorbs most of the drugs [5,6].

Benefits of DDS

●    It is possible to enhance the bio availability of different therapeutic bodes, particularly for the ones which are metabolized in the stomach or upper GIT by this approach of DDS compared to administration of drug delivery which doesn’t have a long duration of retention. In addition, there are different factors associated with transit and absorption of drugs in GIT which serve concomitantly for influencing drug absorption magnitude.

●     Sustained-release, for drugs with a less half-life, might enable reduced dosing frequency with better patient compliance, and product flip-flop pharmaceutics.

●    There is an advantage over conventional systems because it can be utilized for overcoming the side-effects of GRT or gastric retention time and GET or gastric-emptying time. They are predicted to be float on gastric fluid without influencing intrinsic rate because their density in bulk is lower in comparison with gastric fluids.

●     SSDDS can sustain, prolong, and produce drug release forms which seem to avail simple therapy in small intestine and stomach. Thus, they are helpful in disorder treatment related to small intestine and stomach.

●     Specific, slow delivery and controlled form of dosage offer sufficient action at the site, and hence reduces the elimination of systemic drug exposure. Undesirable side-effects are reduced by this SSDDS.

●     The fluctuation of effects and drug concentrations are minimized by dosage forms specific to the stomach. Thus, adverse effects dependent on concentration which are related to peak concentrations can be easily presented. For drugs with little therapeutic index, this feature is highly significant.

●     This kind of drug delivery can also reduce the body counter activity which leads to higher efficiency of a drug.

●     Fluctuation reduction in the concentration of drug makes it possible to achieve better selective activation of receptor.

●    A sustained drug model from doses specific to stomach allow an increment in time duration over a high or critical conception and hence improves both chemical outcomes and pharmacological effects [7-9].

Drawbacks of SSDDS

●   In the acidic environment, unstable drug substances are not suitable elements to be integrated into systems.

● In addition, the drugs which are absorbed significantly as they pass through gastrointestinal tract, which also undergo metabolism at first pass, are the only useful candidates.

●   In the stomach, a very high fluid level is required by these systems for delivery of drug to float and efficiently work.

●  This method is not suitable for all those drugs which have stability or solubility issues in the gastrointestinal tract.

●    All those drugs which resist gastric mucosa are not suitable and also not desirable.

●   It is significant to administer the form of dosage with water up to 200-250 ml or a full glass.

●  Significant advantages are not offered by these systems over conventional forms of drug dosage which are absorbed as they pass through gastrointestinal tract [10].

Anatomy of small intestine and stomach associated with SSDDS [11,12]

There are three main parts in which GIT or gastrointestinal tract can be separated:

●    Small intestine – ileum, jejunum, and duodenum

●    Large intestine

●    Stomach

It can be said that gastrointestinal tract is a tube of almost 9m that can extend from anus to mouth. And its function is all about eliminating waste products and taking nutrients by physiological processes like excretion, motility, secretion, absorption, and digestion. There are 3 layers of muscle in the stomach referred to as oblique muscle and it is placed in the stomach’s proximal part, branching over higher regions and funds of gastric body.

The stomach is separated into pylorus, body, and funds. Meanwhile, the stomach is present in the portion of abdomen’s upper left hand. Storing the food temporarily, grinding it, and releasing it gradually into the duodenum is its main function.

Physiology of the Stomach [13]

It is a large part of the digestive tube between small intestine and esophagus. The stomach, in its empty state, is contracted and subcompact and mucous are thrown up into layers or folds, referred to as rugger. It is covered by four important kinds of epithelial cells which extend into glands and gastric pits.

1.      G cells- which secrete gastric.

2.      Chief cells- which secrete pepsin.

3.      Parietal cells- which secrete H Cl.

4.      Mucous cells- alkaline mucus is secreted by it.

Gastric empty rate and gastric motility

There exist two unique patterns of gastrointestinal secretion and motility to fed and fasted state. The bio availability of drugs which are orally administered depends on the feeding state. Meanwhile, in the fasted state, an inter-digestive group of electric events characterize it, referred to as migrating motor or hydroelectric cycle complex. It is separated into four phases including:

●    Basal phase or phase I –it lasts to 60-40 min with uncommon contractions.

●    Preburust phase or phase II – it lasts to 60-40 min with intermittent contractions and potential.

●     Burst phase or phase III –it lasts to 6-4 min. Regular and intense contraction takes place in this period for short periods. Because of these contractions, undigested food is seemingly swept to intestine from stomach. Housekeeper waves is the term which is used for it.

●    Phase IV –It lasts to 5-0 min and it takes place between phases I and III for almost 2 consecutive cycles. After a mixed meal is ingested, the contraction pattern changes to fasted state from fed; these patterns decrease the size of particles of food to less than 1 millimetre; and the nit is pushed to pylorus in the form of suspension. During the state of fed, MM onset is delayed which seems to result in a decrement of GER.

Different factors influencing gastric retention [14-16]

Densities- it is significant for dosage form density to be less than gastric content density (1.004g/ml).

Dosage Size- diameter of dosage form which is over 7.5mm has more residence timing in comparison with the diameter of 9.9mm.

Shape –tetrahedron shape seems to reside in the stomach for a longer time in comparison with other devices of the same size.

Multiple or single unit formulation- formulation of multiple unit indicates a more predictable profile of release and insignificant impairing of capability because of unit failure, enabling unit co-administration with different profiles of release or containing unsuitable substances while permitting a larger safety margin against the failure of dosage form in comparison with dosage form of a single unit.

Unfed or fed state- GI motility, under different fasting conditions, is characterized by periods of motor activity which takes place every 2-1.5 hours. Undigested material is swept by MMC from the stomach and if formulation timing coincides with the timing of MMC, the timing of unit can be quite short but MMC, in the fast state, is delayed while the GRT is prolonged.

Meal nature- feeding of fatty acids or indigestible polymers can change the pattern of motility to a fed state, hence drug release is prolonged and GET is decreased.

Caloric content- Specifically, GRT can be raised by almost 10-4 times with meals which are high in fat and protein.

Frequency of feed- It is possible to increase GRT to even 400 min when given successive meals as compared with an individual meal because of MMC at low frequency.

Gender- The mean GRT in men is less in comparison with race and age-matched counterparts in spite of body surface, weight, and height.

Age- Individuals with age over seventy have a longer GRT.

Administration of concomitant drug –GRT can be prolonged by different anticholinergics like codeine and opiates.

List of drugs suitable in formulating as SSDDS [17]

Generally, suitable candidates for dosage forms which are gastro retentive are molecules which have an inefficient colonic absorption. They are characterized by efficient absorption properties at GIT’s upper part.

•         Drugs which act locally.

e.g., drugs for Misoprostol, H. Pylroi viz., and antacids.

•         In the stomach, drugs which are absorbed primarily.

e.g., Amoxicillin

•         At alkaline pH, drugs which are soluble inefficiently.

e.g., Verapamil, Diazepam, and Furosemideetc.

•         Those drugs which have a narrow absorption window.

e.g., Levodopa, Methotrexate, and Cyclosporine among others.

•         Drugs which are rapidly absorbed from GIT.

e.g., Tetracycline and Metonidazole.

•         All drugs which degrade in colons.

e.g., Metformin HCl, Ranitidine etc.

•         Drugs which seem to disturb colonic microbes.

e.g., different antibiotics against pylori helicobacter.

Un-suitable drugs for formulating as SSDDS [18]

Following are the unsuitable candidates:

•         All drugs which have little solubility.

Phenytoin is an example.

•         All those which are unstable in gastric environment.

Erythromycin is an example.

•         All those drugs which are utilized for selective release in colons.

e.g., corticosteroids and 5- aminosalicylic acid are the examples.

SSDDS Marketed Products[19-23]

Classification of SSDDS [24-26]

A.    Effervescent systems

•         Systems of gas generation

•         Systems containing volatile liquid

B.     Non-effervescent systems:

•         Compartment system

•         Microporous or Delivery Device of Intragastric Floating Drug

•         Hollow microballoons/microspheres

•         Alginate beds

•         Barrier system of colloidal gel

A. Effervescent Systems:

Actually, these matrix kinds of different systems are developed with the assistance of swellable polymers like chitosan and methylcellulose, and other effervescent compounds like citric acid, tartaric acid, and sodium bicarbonate. They are developed in such a manner that when they come in contact with gastric contents, carbon dioxide is liberated while gas is entrapped in the form of swollen hydrocolloids which offer float properties to forms of dosage.

•         Gas-generating Systems:

Effervescent reactions are utilized by these delivery systems between bicarbonate/carbonate salts and tartaric/citric acid for liberating carbon dioxide, which is trapped in the layer of hydrocolloid. Thus, its specific gravity is decreased and the ability of floating is developed.

•         Volatile liquid containing systems:

Actually, the GRT of a DDS can be controlled in integrating an inflatable chamber containing liquid, which gasifies at the temperature of body for causing chamber inflation in the stomach. The device might even have a bio-erodible plug of Polyethylene and PVA among others which dissolve gradually and cause the inflatable chamber to let go of gas while collapsing after a specific time for permitting inflatable systems’ spontaneous ejection.

B. Non-effervescent systems:

A swellable cellulose type or gelforming like polystyrene, polymethacrylate, polycarbonate, polysaccharides, and hydrocolloids are utilized by non-effervescent forms of floating dosage. The method of formulation involves a simple procedure of mixing the gel-forming hydrocolloid and drug. This dosage form, after oral administration, swells when it comes in contact with different gastric fluids and < 1 of bulk density is attained. Buoyancy is imparted by the swollen matrix to form of dosage by the air which is trapped within swollen matrix. This structure serves as a reservoir and enables sustained drug release through a gelatinous mass.

•         Systems of colloidal gel barrier

HBSTM or hydrodynamical balance system was designed first by Tossounian and Sheth in 1975. Drugs are contained in such systems with hydrocolloids which are meant to float on contents of the stomach. A high-level gel-forming hydrocolloid is incorporated by this system likePolysacchrides, NaCMC, HPMC, HEC and polymers which form matrix-like polystyrene, polyacylates, and polycarbophil integrated either in capsules or tablets. On contacting gastric fluid, hydrocolloid in systems forms and hydrates a gel barrier around the surface of gel. Buoyancy is conferred by the air which is trapped by swollen polymers maintaining a density which is less than one [24].

•         Alginate beads:

Multi-unit forms of floating dosage have been produced from dried-freeze calcium alginate. And spherical beads of almost 2.5 mm in roundness or diameter can be developed by dropping a solution of sodium alginate into calcium chloride solution, causing it to be precipitated. Then, the beads are separated, dried-freeze at -40 Celsius, and frozen in the liquid nitrogen, leading the development of porous system, which is capable of maintaining a floating cover for more than twelve hours.

•         Hollow microspheres:

Microballoons or hollow microspheres, consisting of ibuprofen in outer shells were developed by a competent method of emulsion-solvent diffusion. The drug solution of ethanol dichloromethane and enteric acrylic polymer was seemingly poured into a PVA’s agitated solution which was controlled thermally at 40 Celsius. Dispersed polymer droplets are generated in the gas phase by dichloromethane evaporation in the internal cavities of polymers with drugs. Over the surface of dissolution media, microballoons consistently flow for over twelve hours [25].

•         Microporous/ Intragastriccompartment system:

In the microporous compartment, the system which is composed of drug reservoir is encapsulated with pores on the bottom and top surfaces. Reservoir compartment’s peripheral walls were sealed for preventing contact of stomach walls with the undissolved drug. Novel retentive form of levodopa gastro is seemingly based on polymeric unfolding membranes which integrate high rigidity with extended dimensions. It was folded into gelatin capsules. It was shown in vitro studies that unfolded forms reached within fifteen minutes after precise administration and it was confirmed in beagle drugs. For approximately two hours, the unfolded form stayed. And it was concluded that this form of dosage could optimize therapy of narrow window absorption. But there are chances of polymeric films getting stuck in esophagus and becoming the cause of intense discomfort to drug related wounds, and rigid dosage form’s repeated administration might result in gastric obstructions [26].

Approaches to increase GRT or gastric retention time in SSDDS

In the stomach, prolonged time of gastric retention could be beneficial for local action in small intestine’s upper part e.g., peptic ulcer treatment etc. Over past years, various gastroretentive or stomach specific delivery approaches have been developed and designed which include:

a)      HBS or Hydrodynamically Balanced Systems

b)     Systems with low-density

c)      Gas-generating systems

d)     Systems which form raft

e)      Floating systems.

f)       Systems which are bioadhesive liposomal

g)      Ion Exchange Resins

h)     Superporous Hydrogels

i)       Expanding and Swelling Systems

j)       Mucoadhesive or Bioadhesive systems

k)     Systems with high-density

a)      High-density systems

~3 g/cm³ as a density of systems is retained in stomach rugae and can withstand its several peristaltic movements. With over 2.4–2.8 g/cm3 of threshold density, such systems can be simply retained in stomach’s lower part. Meanwhile, sedimentation has been selected as a mechanism of retention for pellets which are small enough for being retained in the folds or rugae of stomach near the region of pyloric, which is an organ part with the lowest position in a straight posture. Meanwhile, dense pellets entrapped in rugae(approximately 3g/cm3)tend toendure the peristaltic movements of walls of stomach. The transit time of GI can be extended to 25 from 5.8 hours, depending less on pellet diameter and more on density. Densities near threshold density appear to be important for the extension of residence time. Some commonly utilized excipients include iron powder, titanium dioxide, zinc oxide, and barium sulphate etc. Density is increased by 1.5–2.4g/cm³by these materials [27-30].

b)     Mucoadhesiveor BioadhesiveSystems

Mucoadhesion is a term which is utilized commonly for describing an interaction between the layer of mucin which lines the bioadhesive polymer and GIT. BDDS or bioadhesive drug delivery systems are utilized like a delivery device for enhancing drug absorption in lumen in a spite-specific way. This method includes a utilization of bioadhesive polymers, which can stick to the stomach epithelial surface [31]. Hence, they increase the time of gastric retention. Bioadhesion can be described through several concepts:

●    Theory of absorptions which explains that it is because of either hydrogen bonding or Vander Waal forces.

●  Attractive electrostatic forces are proposed by the electron theory between bioadhesive material and network of glycoprotein mucin.

●   In addition, the wetting theory is based on the capability of bioadhesive polymers of developing and spreading intimate contact with different mucous layers, and finally, physical entanglement is proposed by diffusion theory of polymer chains and mucin strands, or conversion of mucin strands into polymer substrate’s porous structure.

●  Physical entanglement is proposed by the diffusion theory of polymer chains, mucin strands, or mucin strand interpretation into the polymer substrate’s porous structure [32,33].

c)  Expanding and Swelling Systems

Expanding and swelling systems are forms of dosage that swell to a certain extent which prevents their exit from pylorus. Consequently, a form of dosage is retained for a long time in stomach. These systems might be referred as systems of plug type since a tendency is exhibited by them to be logged at pyloric sphincter. Controlled drug release and swelling might be achieved on the contact of DDS with gastric fluid; water is imbibed by polymer and swells. The presence of chemical-physical crosslinks results in swelling of polymer in the network of hydrophilic polymer. Gastric retention is enabled by the bulk while maintaining the stomach in a state of fed, reducing housekeeper waves. Swelling hydrogels or medicated polymer sheets are examples of such DDS. A balance between the extent and rate of swelling and erosion rate of polymer is significant in achieving optimum benefits and avoiding negative impacts [34,35].

d)  Super porous Hydrogels

It can be said that in this approach, for improving the GRT or gastric retention time, super porous hydrogels of an average size of pore larger than 100 micrometer, swell to the size of equilibrium within only a minute because of quick water uptake by capillary wetting through various interconnected pores. These pores are also open. To a large size, they swell with ratio of swelling: hundred or more than hundred, and are intended to have enough mechanical power for withstanding pressure of gastric contractions. Actually, this is acquired by co-processing with croscarmellose sodium, which is a hydrophilic particulate material. It is capable of creating a dispersed phase within the consistent matrix of polymer during the process of synthesis. The composites of superporous hydrogel seem to stay in the upper part of GIT for more than a day. In the field, recent advancements have led to hybrids of superporous hydrogel, which are developed with the addition of water or hydrophilic dispersible polymer which can be cross-linked after the formation of superporous hydrogel. Some examples of hybrid agents involve polysaccharides like chitosan, pectin, and sodium alginate [36].

e)   Ion-Exchange Resins

Generally, a coated ion bead formulation of ion exchange has been determined to have different gastric retentive characteristics, which was supplied with bicarbonates. Resins of ion exchange are loaded with bicarbonates and a drug which is negatively charged is connected to the resin, then the resultant beads were encapsulated in a specific semipermeable membrane for overcoming the immediate reduction of carbon dioxide. Upon entering the acidic stomach environment, exchange of bicarbonate and chloride ion occurred. Due to it, carbon dioxide gas was released and was trapped in the layer or membrane, thus carrying beads towards the surface of gastric content and developing a layer of floating beads, in contrast with uncoated beads.

f)    Bio adhesive Liposomal  Systems

We can say that such systems are developed by polymer coating for facilitating enteral absorption of drugs which are not absorbed properly. Generally, liposomes are coated with different mucoadhesive polymers like carboxymethylcithosan, carbocymethyl chitin, carbopol, and chitosan. When mucoadhesion occurs in liposomes, it enhances the retention timing of dosage [37,38].

g)    Floating Drug Delivery Systems

FDDS is one of the most significant approaches utilized in achieving gastric retention for obtaining efficient drug bioavailability. The system of delivery is desirable for different drugs with a window of absorption in the stomach or in small intestine’s upper part. These systems seem to have a bulk density which is lower than that of fluids in the stomach and thus remain floating in the stomach without influencing GET for a longer time. As the system is floating on the surface, the release of drug takes place slowly at a rate which is deemed suitable. It results in an increment in GRT along with better control of overall fluctuations in the concentration of plasma drug [39].

Following are the most important requirements for an FDDS:

●    A specific gravity which is lower than contents in stomach, should be maintained by it (1.004 gm/cm3).

●    A cohesive barrier of gel should be formed by it.

●    Contents should be released slowly for serving as a reservoir or source [40,41].

h)   Raft forming systems

Systems of raft forming have gotten a lot of attention for drug delivery for different gastrointestinal-associated disorders and infections. Floating rafts have been utilized in treating GERD or gastroesophageal reflux disease. Actually, the mechanism involved in the formation of raft involves the development of cohesive viscous gel in a contact with gastric fluids, wherein each and every portion of liquid seems to swell to form a consistent layer, referred to as a raft. It floats on fluids of the stomach because it has a low density formed by the development of carbon dioxide. Normally, ingredients of this system include alkaline bicarbonates and gel-forming substances which are responsible for carbon dioxide formation to make systems less dense and offer floating properties. A floating system of antacid raft has been explained by Jorgen et al. A gel forming element is included in this system of sodium bicarbonate and an acid neutralizer which creates a raft or gel of foaming sodium alginate. When it comes in a contact with fluids of stomach, it floats on these fluids while preventing the reflux of contents of stomach into esophagus by serving as a barrier between esophagus and stomach [42,43].

i)       (Effervescent) Gas Generating Systems

We can say that in this system, float ability can be acquired by gas bubble generation. They are generated in such a manner that when in contact with the acidic contents of stomach, carbon dioxide is liberated and it is entrapped in hydro colloids, which offers floating properties to dosage. In nitro, the time of lag before unit floats is less than one minute and floating is extended to 10-8 hours. Multiplayer or bi layer systems have been created in which recipients and drugs can be independently formulated, and unit for generating gas can be integrated into any layer of MUS or multiple unit systems, which evades the emptying process of all-or-nothing in systems of single unit [44].

j)  Low Density Systems

Systems which generate gas seem to suffer from time of lag before floating on the contents of stomach, during which the form of dosage might undergo initial evacuation through the part of pyloric sphincter. Therefore, systems with low density and immediate buoyancy have been produced. They are made up of materials which have low-density and are capable of entrapping air or oil. Most examples of MUS are micro balloons, floating pellets, emulate beads, micro particles, and hollow beads [45].

k)   HBC or Hydro dynamically balanced systems

Such systems are suited best for drugs with a better solubility in an acidic environment and sites of absorption in the small intestine’s upper part. For remaining in the stomach for a longer period of time, dosage forms must have a density less than unity. And they have to stay in the stomach while maintaining its structural integrity and releasing drug constantly from the dosage. These systems are individual-unit dosage forms which contain a single or more than one hydrophilic polymer which can form gel. In the development of these systems, some commonly utilized recipients include clinical acid, agar, polystyrene, polyacrylamide, polymorphic, Nacre or sodium carboxylic cellulose, HP C or hydroponically cellulose, HE or hydrothermal cellulose, and HP or hydroponically methyl cellulose[46,47]

SSDDS and market’s industrial aspects.

SSDDS are capable of overcoming side-effects related to oral delivery of drug by beating naturally-occurring physiological principles. Several gastroretentive procedures have been created in the past, but some of them achieved practical effectiveness. Disease states’ pharmacotherapy can be amended by repurposing of drug through GRDDS. Furthermore, assessment of the influence of fasted and fed condition on product performance must be carried out during the initial phases of development. Technology of dual working will be a possible way of overcoming side-effects related to GRDDS. Prior to the development of product, principles of process and scaleup validation should be considered for improving market availability and quality of SSDDS. Information about regulatory aspects will be helpful in delivering a product to markets in a cost-efficient way and short-time.

Influence of BaSO4 on floating

Barium sulfate is utilized by x-ray imaging as an implemented contrast material of X-ray for diagnostic or imaging purposes because of its mass attenuation coefficient. Barium sulfate is actually a yellowish to white powder having specifications of low solubility, high specific gravity, opacity, and inertness. It is utilized only rectally or orally. This element is not metabolized or absorbed in physiological conditions and is seemingly erected through feces in an unchanged form. Visualization is improved by barium sulfate on images of X-ray, as barium sulfate’s X-ray attenuation offers an eligible contrast in imaging of CT [48].