INTRODUCTION:

Everypharmaceutical researcher and industry wants to create a safe and effective medication delivery method. Drug administration via the transdermal method can provide both systemic and local therapeutic effects. Because it avoids gastrointestinal side effects and first-pass metabolism, transdermal drug delivery is a desirable alternative to oral medication administration.

It can also overcome the low patient compliance linked to conventional drug delivery methods. Self-administered transdermal drug delivery enables the medication to penetrate intact skin over a predetermined amount of time to produce a local or systemic every pharmaceutical researcher and industry wants to develop a safe and effective drug delivery technology. Drug administration via the transdermal method can provide both systemic and local therapeutic effects. Because it avoids gastrointestinal side effects and first-pass metabolism, transdermal drug delivery is a desirable alternative to oral medication administration. It can also overcome the low patient compliance linked to conventional drug delivery methods. Self-administered transdermal drug delivery enables the medication to penetrate intact skin over a predetermined amount of time to produce a local or systemic.

There has been a rise in interest in transdermal drug delivery systems (TDDS) for both systemic drug delivery and local therapeutic effects on sick skin (topical delivery). The ability to avoid issues with gastric irritation, pH, and emptying rate effects; avoid hepatic first-pass metabolism, thereby increasing the drug's bioavailability; lower the risk of systemic side effects by minimizing plasma concentrations compared to oral therapy; and provide a sustained release of the drug at the site of application are just a few of the many important advantages of using the skin as a drug delivery site over many other routes of drug administration, including fast therapy termination by removing the formulation or device, minimizing medication plasma level variations, and avoiding injection-related pain. Additionally, pulsed entrance into the systemic circulation, which frequently results in unfavorable side effects, can be eliminated via transdermal distribution. Diabetes mellitus is a serious and expanding global health issue that contributes significantly to long-term illness and premature mortality. Hyperglycemia, a high blood glucose concentration brought on by insulin insufficiency, is the hallmark of this chronic metabolic disease, which frequently coexists with insulin resistance. Repaglinide is an oral medicate on that lowers blood sugar. The goal of the current study was to create a transdermal formulation of repaglinide that uses various grades of HPMC and PVP K30 as polymers to improve patient compliance and sustain drug release to boost bioavailability¹.

Many problems with oral medication distribution, including first-pass hepatic metabolism, enzymatic digestion assault, drug hydrolysis and degradation in acidic environments, drug fluctuations, and gastrointestinal irritation, can be avoided by using transdermal patches. This article examines the variety of transdermal patches on the market, their structural elements, the function of polymers, and the necessary evaluation instruments. Transdermal patches can be used for a variety of medical conditions, including pain treatment, osteoporosis, contraception, motion sickness, angina pectoris, cardiac diseases, and smoking cessation. However, formulation development is still ongoing to enable transdermal patches to administer more difficult medications. The physicochemical characteristics of active and inert ingredients, as well as their suitability for long-term usage, can be taken into consideration while developing transdermal patches. As a result, several physical and chemical methods for creating transdermal patches are being researched. The US Food and Drug Administration (FDA) authorized nicotine patches in 1984, whereas the first transdermal system containing scopolamine was licensed in the US in 1979. Ten years later, transdermal patches for analgesia, pain management, and contraception The FDA approved and commercialized hormone replacement therapy, and advancements in this area are still being made today. A few transdermal patch products now available in the US market are included.

Use of transdermal patches can evade many issues associated with oral drug delivery, such as first-pass hepatic metabolism, enzymatic digestion attack, drug hydrolysis and degradation in acidic media, drug fluctuations, and gastrointestinal irritation. This article reviews various transdermal patches available in the market, their types, structural components, polymer role, and the required assessment tools. Although transdermal patches have medical applications for smoking cessation, pain relief, osteoporosis, contraception, motion sickness, angina pectoris, and cardiac disorders, advances in formulation development are ongoing to make transdermal patches capable of delivering more challenging drugs. Transdermal patches can be tailored and developed according to the physicochemical properties of active and inactive components and applicability for long-term use. Therefore, a number of chemical approaches and physical techniques for transdermal patch development are under investigation³.

HISTORY:

The first transdermal system containing scopolamine was approved in the United States in 1979; the US Food and Drug Administration (FDA) approved nicotine patches in 1984. A decade later, transdermal patches for pain relief, analgesic activity, contraceptivetion, and hormone replacement therapy were FDA approved and marketed, and the Progress in this field continues today. Table I shows some transdermal patch products currently on the US market³.

Table 1. Drug product and clinical use of transdermal patches on the current market

Drug	Product Name	Clinical use

Scopolamine	Transderm-Scop	Motion sickness
Nitroglycerin	Transderm-Nitro	Angina pectoris
Clonidine	Catapres-TTS	High blood pressure
Estradiol	Estraderm	Menopause
Fentanyl	Duragesic	Chronic pain
Nicotin	Nicoderm	Smoking cessation
Testosterone	Testoderm	Testosterone low level
Lidocaine/epinephrine	lontocaine	Pain relief
Estradiol/norethidrone	Combipatch	Menopause
Lidocaine	Lidoderm	Pain relief
Norelgestromin	Ortho Evra	Contraception
Estradiol/levonorgestrel	Climara Pro	Menopause
Oxybutynin	Oxytrol	Overactive bladder
Lidocaine (ultrasound)	SonoPrep	Pain relief
Lidocaine/tetracaine	Synera	Pain relief
Fentanyl HCI	lonsys	Postoperative pain
Methylphenidate	Daytrana	ADHD
Selegiline	Emsam	Depression
Rotigotine	Neupro	Parkinson's disease
Rivastigmine	Exelon	Dementia

Types of Transdermal Patches:

1. Single-Layer Drug-in-Adhesive Patches:

Drug dispersion is achieved by using a single layer of sticky polymer as a reservoir. The single layer is covered with an impermeable backing laminate. The medication is released from the backing laminate layer supporting the drug reservoir after being deposited in and adhering to the single polymer layer.

Fig no.1 Single and Multilayer Drug-in Adhesive Patches

2. Multilayer Drug-in-Adhesive Patches:

A drug reservoir layer and an adhesive layer with regulated medication release over time make up multilayer transdermal patches. Multilayer systems comprise both a permanent backing laminate and a temporary protective layer. Hormone therapy, painkillers, and medications that promote quitting smoking are all administered via multilayer patches; drug administration can be extended for up to seven days.

3. Vapor transdermal patches:

The single layer of adhesive polymer used in vapor transdermal patches has the ability to release vapor. There are several vapor dermal patches on the market that serve various functions. For instance, nicotine vapor transdermal patches called Nicoderm CQ contain essential oils that, when released, can aid in quitting smoking. In 2007, this product was released onto the European market. Another kind of essential oil-containing vapor patch that can be used for decongestion is Al Tacura. There are also various kinds of vapor patches on the market that act as sedatives or antidepressants.

4. Reservoir:

The reservoir transdermal system has a distinct drug layer, in contrast to the single-layer and multi-layer drug- in-adhesive systems. The sticky layer separates the drug layer, which is a liquid compartment with a drug suspension or solution. The backing layer supports this patch as well. The rate of release in this kind of system is zero order.

Fig. 2 Design of reservoir type transdermal patch

5. Matrix:

The drug layer of the Matrix system is a semisolid matrix that holds a drug suspension or solution. In this patch, the medication layer is partially covered by the adhesive layer. Another name for a monolithic device.²

Fig. 3 Design of Matrix Type Transdermal Patch

The Main Components to a Transdermal

1. Matrices & polymers

Fig no. 4 Matrices and Polymers

Coreof TDDS, which regulates the drug's release. Polymers should be non-toxic, chemically non-reactive, and inexpensive. They should also not break down while being stored. For instance, cellulose derivatives, zein, gelatin, shellac, waxes, gums, polybutadiene, hydrin rubber, polyisobutylene, silicon rubber, nitrile, acrylonitrile, neoprene, polyvinyl alcohol, polyvinyl chloride, polyethylene, polypropylene, polyacrylate, polyamide, polyurea, polyvinylpyrrolidone, and polymethyl methacrylate.

Table no 2. Types of polymers

Natural polymer	Synthetic elastomer	Synthetic polymer

Gelatin	Neoprene	Polyetylene
Gum Arabic	Silicon Rubber	Polystyrene
Starch	Butyl Rubber	PVC
Shellac	Chloroprene	PVC
Zein	Polysiloxane	Polyste

● Ethylene-vinyl acetate (EVA)—a widely used matrix polymer (controls diffusion). Silicone elastomers are biocompatible and used in drug-in-adhesive systems.

● Polyisobutylene (PIB)—tacky adhesive and matrix. Polyurethane—used for membranes and some matrices.

● Hydrogels (crosslinked polyacrylics, PVA)—for hydrophilic drugs.

2. Drug:

For medications with suitable pharmacology and physical chemistry, the transdermal route is a very appealing choice. Drugs with a short half-life, a limited therapeutic window, or substantial first-pass metabolism can benefit greatly from transdermal patches. such as nitroglycerin, fentanyl, etc.

3. Permeation Enhancers:

Raise the stratum corneum's permeability to get greater therapeutic medication levels. These come in three varieties: two-component systems, surface active agents, and lipophilic solvents. For instance, DMSO.

4. Adhesive:

Improve the stratum corneum's permeability to get greater therapeutic levels of the medication.

5. Laminates for backing:

A backing laminate is the protective outer covering of Transdermal Medication Delivery Systems (TDDS) that keeps out external factors like moisture and oxygen, stops the medication from escaping, and offers structural support. Chemical resistance, low water vapor transfer, and flexibility for pleasant application are important characteristics; materials including vinyl films, polyester, and polyethylene are frequently utilized. and ought to be highly flexible or have a low modulus. such as polyethylene and vinyl.

6. Release liner:

To avoid contamination and drug loss prior to administration, the release liner is a protective covering that covers the adhesive portion of the patch in transdermal drug delivery systems (TDDS). In order to ensure that the adhesive and active ingredients are preserved for efficient medication administration, it is removed right before the patch is utilized. The liner is a crucial part, and the effectiveness of the patch depends on its constant quality. Additionally, it keeps the patch safe while being stored. Before using, the liner is taken out.

7. Enhancers of Permeation:

Compounds used in transdermal drug delivery systems (TDDS) improve the skin's permeability, allowing more medication to flow through and getting beyond the skin's natural barrier. They function by changing the skin in a reversible way, such as by increasing the water content between skin cells, disrupting the lipid barrier, or improving drug solubility. Chemical enhancers such as alcohols, sulfoxides, and surfactants are examples of permeation enhancers⁴.

Patches Based on Microneedles:

There are various forms of microneedles, each with distinct traits and qualities, as illustrated in. Overall, four basic types of microneedle-based patches have been created, including solid, hollow, dissolving, and coated microneedles. The choice of microneedle type relies on the unique application and requirements of the user.

1. Sturdy Microneedles These are the most basic kind of microneedles, made up of solid needles that pierce the skin to form microscopic channels. Drug delivery and cosmetic procedures frequently employ solid microneedles.

2. Microneedles that are hollow: The hollow core of these microneedles makes it possible to inject medications or liquids into the skin. Interstitial fluid collection and transdermal medication distribution are common uses for hollow microneedles.

3. Coated Microneedles: The coating on these microneedles dissolves when they penetrate the skin, releasing medications or other substances. Transdermal medication delivery frequently makes use of coated microneedles.

4. Dissolving/ Degradable Microneedles: These microneedles enable the regulated release of medications or other substances since they are composed of ingredients that dissolve in the skin. Vaccines and other medication delivery applications frequently make use of dissolving microneedles⁵.

Transdermal Patch Evaluation:

A. Physicochemical assessment

B. In vitro assessment

C. In vivo assessment

A. Physicochemical Assessment:

Visual inspection of transdermal patches was done for:

1. The Thickness:

Three patches were measured for thickness at five different sites using a micrometer, and the average was calculated.

2. Folding Endurance:

A manual measurement was made of the patches' folding durability. It is determined by how many times the film is folded at the same spot, either to cause apparent fractures or to break it. This is required to assess the sample's resistance to folding. This also indicates brittleness.

The film's folding endurance was assessed by repeatedly folding a small strip of film at a predetermined spot measuring 2cm by 2cm (4cm²) until a crack appeared and the film broke.

3. Weight Uniformity:

Weight discrepancies between the manufactured patches can result in variances in drug content and in vitro behavior. A study was done in which 5 patches were weighed on an electronic scale. Every patch should have the same size (1cm × 1cm) and be selected at random.

The average weight and standard deviation of a patch were calculated using the following formulas.

The average patch weight is equal to the total patch weight divided by five (x-X). The standard deviation is 2/(n-1) where X is the average weight and x is the weight of the specific patch.

The number of patches is indicated by n.

4. Tensile Strength:

Tensile strength was measured using equipment made in our lab. The average weight of three patches was used to calculate tensile strength.

· A sharp blade was used to cut a small film strip (4 x 1cm) on a glass plate. One end of the film was fastened between adhesive tapes to support it when it was placed in the film holder. Another end of the film was sandwiched between the adhesive tapes with a small pin to keep the strip straight while it stretched.

A hook was inserted after a tiny hole was made in the adhesive tape close to the pin. The small pan was fastened to a thread that was hooked to the hook and passed across the pulley.

To determine the film's tensile strength, it was pulled using a pulley system. To increase the pulling force until the film breaks, weights are progressively added to the pan. The elongation was determined by measuring the distance the pointer traveled on graph paper prior to the film breaking. The weight needed to shatter the film was referred to as the break force.

Tensile strength was calculated using the following formula:

Tensile load at break/a.b. (1+L/L) equals tensile strength.

where L denotes the elongation at break, and a, b, and L stand for the strip's width, thickness, and length, respectively. The amount of weight needed to break is known as the break force.

IB-IO/IO x 100 = Film elongation (kg), where IO stands for the film's initial duration. IB stands for the duration of film breaks.

5. Probe Tack Test:

Tack is defined as the force needed to draw a probe away from an adhesive at a predetermined rate.

6. Rolling Ball Test:

This test measures how far a stainless-steel ball moves along an adhesive that faces upward. The ball will move farther if the adhesive is less sticky.

B. IN VITRO Release Studies:

Transdermal patches can be investigated in vitro using Franz diffusion cells, which are made up of donor and receptor compartments, according to in vitro release studies. The receptor compartment can hold 5–12ml and has an effective surface area of 1–5 cm². The diffusion buffer is continuously stirred at 600rpm by a magnetic bar.

To keep most of the solution at the same temperature, thermostated water is circulated through a water jacket that surrounds the receptor compartment. Maintaining the sink's condition is essential, and the drug content is evaluated using the right method.

C. IN VIVO Release Studies:

Transdermal patches may be analyzed in vitro using Franz diffusion cells, which are made up of donor and receptor compartments, according to in vitro release studies.

The receptor compartment can hold 5–12ml and has an effective surface area of 1–5 cm². The diffusion buffer is continuously stirred at 600rpm by a magnetic bar.

Recent Advancement of Transdermal Patch Smart Patches:

Sensors and other technology included in smart patches allow them to monitor patient circumstances and modify medication distribution as necessary. A team of researchers created a smart patch sensor device based on microneedles in 2014 to provide diabetics with continuous, painless intradermal glucose monitoring. This patch employs a conducting polymer, such as poly (3,4-ethylenedioxythiophene) (PEDOT), to both immobilize the glucose-specific c-enzyme glucose oxidase (GOx) and act as an electrical mediator for glucose sensing.

Fig no. 6 Smart patches

The skin layer is painlessly penetrated by the microneedle-based patch. Insulin and the glucose-sensing enzyme glucose oxidase, which changes glucose into gluconate, are both present in the smart patch. Insulin release and nanoparticle breakdown are triggered by increased glucose oxidase activity in response to elevated glucose.

1. Dissolving/Degradable Patches

Fig no. 7 Dissolving patches

The microneedles in these patches are made out of biodegradable materials. After gentamicin has been released from the patch, the microneedles dissolve on the skin.

2. Three-Dimensional (3D)-Printed Patches:

Researchers are using 3D printing technology to create customized transdermal patches that can be tailored to the individual needs of each patient. One good example is the use of a 3D-printed patch for wound healing. In a study by Jang et al., gelatin methacrylate (GelMA) was tested as a viable option with tunable physical properties.

3. Transdermal Vaccination Patches:

Transdermal patches, which may administer vaccines via the skin, are being developed by researchers as a possible less painful and more convenient option than injections. The microneedle-based smallpox vaccine patch is a prime example. Neutralizing antibodies were produced three weeks after the mice were immunized with this vaccination patch. Levels were sustained for 12 weeks, and IFN-γ-secreting cells significantly increased, indicating that the transdermal patch might be used as a different immunization and preservation delivery method.

4. Insulin Delivery via Transdermal Patches:

To treat diabetics, transdermal insulin delivery patches are used to transport insulin through the skin and into the bloodstream. The pancreas secretes the hormone insulin, which helps control the body's blood sugar levels.

Because they are unable to adequately create insulin or utilize the insulin that their bodies do produce, diabetics may have elevated blood sugar levels,Ionic liquids, choline bicarbonate and geranic acid (CAGE), liposomes, an d nanomaterials have all been reported as novel methods of delivering insulin thus far.When it comes to insulin delivery, transdermal patches can offer a discreet and easy substitute for more conventional techniques like insul in pumps and injections.

5. Cardiovascular Disease Transdermal Patches:

Pharmacokinetics (PK) and pharmacodynamics (PD) are often modified in a heart failure scenario to account for hypoperfusion systemic circumstances brought on by a decreased cardiac ejection fraction. Renal failure also results in decreased medication metabolism and metabolite clearance. Drug absorption is further hampered by hypoalbuminemia and hepatic congestion brought on by heart failure. Consequently, a drug delivery option is offered by transdermal patch delivery devices. Propranolol, for instance, is a nonselective beta-adrenergic blocker. When administered orally, its hepatic first-pass metabolism is significantly changed, and its bioavailability is roughly 23%. An earlier investigation using rabbits revealed that oral propranolol produced a Cmax of 56.4ng/mL in 13.2 minutes. However, its bioavailability was 12.3% because of the involvement of liver metabolism. Conversely, the transdermal propranolol patch had a bioavailability of 74.8% greater than oral propranolol, reaching a steady-state plasma concentration (Css) of 9.3ng/mL after an initial lag time of 8 hours⁵.

Benefits:

1. It is a practical approach that just needs to be applied once a week. A straightforward dosage schedule like this can help patients stick to their medication routine.

2. For patients who are intolerant of oral dosage forms, transdermal medication delivery provides an alternate mode of administration

3. Patients who are sick or asleep benefit much from it.

4. Because transdermal distribution avoids direct effects on the stomach and intestine, medications that disturb the gastrointestinal tract may be suitable candidates.

5. Medications that are broken down by the gastrointestinal system's acids and enzymes might potentially be worthwhile targets.

6. Transdermal administration can circumvent first-pass metabolism, another restriction on oral medication delivery.

7. Drugs that require relatively consistent plasma levels are very good candidates for transdermal drug delivery².

Drawbacks:

1. The potential for local discomfort at the application location.

2. The medication, the adhesive, or other excipients in the patch formulation may induce erythema, irritation, and local edema.

3. Could result in allergic responses.

4. It is necessary to have a molecular weight of less than 500 Da.

5. Enough lipid and aqueous solubility: For permeate to cross SC and underlying aqueous layers, a log P (octanol/water) between 1 and 3 is needed².

FUTURE SCOPE Of TDDS:

Transdermal delivery technologies appear to have a promising future! Healthcare solutions are becoming more individualized, responsive, and minimally intrusive due to developments in materials science and technology⁷.

Thermal Portion is the formation of aqueous pathways across stratum corneum by the application of pulsed heat, this approach has been used to deliver conventional drugs and to extract intestinal fluid glucose from human subjects. Jet injectors are receiving increased attention now days, which is opening doors for improved device design for controlled, needle- free injection of drug solutions across the skin and into deeper tissue. Small needle is inserted a few milli-meters into skin and drug solution is flowed through the needle into the skin at controlled rates using a micro-infusion pump that is contained within a large patch affixed to skin, morphine has been delivered to humans using this approach. During the past decade several theories have been put forward in addressing the combinations of chemicals and iontophoresis; chemicals and electroporation; chemicals and ultrasound; iontophoresis and ultrasound; electroporation and iontophoresis; and electroporation and ultrasound. Two of the better-known technologies that can help achieve significant skin permeation enhancement are iontophoresis and phonophoresis (sonophoresis). Iontophoresis involves passing a direct electrical current between two electrodes on the skin surface. Phonophoresis uses ultrasonic frequencies to help transfer high molecular weight drugs through the skin. A newer and potentially more promising technology is micro needle- enhanced delivery. These systems use an array of tiny needle-like structures to open pores in the stratum corneum and facilitate drug transport. The statical data showed a market of $ 12.7 billion in the year 2005 which is assumed to increase by $ 21.5 billion in the year 2010 and $ 31.5 billion in the year 2015.

Almost all the pharmaceutical companies are developing TDDS The market for transdermal devices has lately grown at a pace of 25% annually and is predicted to rise in the future. As new devices are developed and the list of transdermal medications on the market grows, this number will rise in the future. As more advancements in design are made, transdermal distribution of analgesics is probably going to become more and more prevalent. To improve safety and effectiveness, research is being conducted.

To provide more accurate medication distribution linked to longer duration of action, as well as to enhance practical aspects like the patch wearer's experience. Improved transdermal technology that uses mechanical energy to boost drug flux over the skin by either changing the skin barrier or raising the energy of the drug molecules is another possible advancement. Many "active" transdermal technologies are being researched for various medications following the successful construction of patches employing iontophoresis⁷.

CONCLUSION:

In medicine therapy, transdermal drug delivery systems are used for reduced absorption, more consistent plasma levels, enhanced bioavailability, fewer side effects, efficacy, and product quality. A patch is composed of several fundamental elements that are crucial to the release of medication via the skin. Regulated therapeutic use will be the main focus of TDDS in the future. Transdermal patches come in a variety of forms, such as matrix, reservoir, membrane matrix hybrid, micro reservoir type, and medication in adhesive type. The basic TDDS components are used to transform these patches into transdermal patches⁴.

CONFLICT OF INTEREST:

The authors have no conflicts of interest regarding this investigation.

ACKNOWLEDGMENTS:

The authors would like to thank Ms. Aditi Marathe, Assistant Professor at Swami Institute of Pharmacy, Abhona, 423502 for their her support.

REFERENCES:

1. Cilurzo F, Gennari CG, Minghetti P. Adhesive properties: a critical issue in transdermal patch development. Expert Opinion on Drug Delivery. 2012 Jan 1; 9(1): 33-45.

2. Dhiman S, Singh TG, RehniAK. Transdermal patches: a recent approach to new drug delivery system. Int J Pharm Pharm Sci. 2011 Sep 3; 3(5): 26-34.

3. Al Hanbali OA, Khan HM, Sarfraz M, Arafat M, Ijaz S, HameedA. Transdermal patches: Design and current approaches to painless drug delivery. Acta Pharmaceutica. 2019 Jun 30; 69(2): 197-215.

4. Pasupuleti P, Bandarapalle K, Sandhya C, Neeraja G, Afzal C, Venkataramana C, VenkatSai G. Transdermal drug delivery systems. Journal of Drug Delivery and Therapeutics. 2023 Feb 1; 13(2): 101-9.

5. WongWF, AngKP, Sethi G, Looi CY. RecentAdvancement of Medical Patch for Transdermal Drug Delivery. Medicina (Kaunas). 2023 Apr 17; 59(4): 778. doi: 10.3390/medicina59040778. PMID: 37109736; PMCID: PMC10142343.

6. Shivalingam MR, BalasubramanianAR, Ramalingam KO. Formulation and evaluation of transdermal patches of pantoprazolesodium. Int J App Pharm. 2021 Sep 7; 13(5): 287-91.

7. Jatav VS, Saggu JS, Jat RK, SharmaAK, Singh RP. Recent advances in development of transdermal patches. Pharmacophore. 2011; 2(6-2011): 251-61.

8. Patel D, Patel N, Parmar M, Kaur N. Transdermal drug delivery system: An Overview. International Journal of Toxicological and Pharmacological Research. 2011; 1: 61-80.

9. Alam MI, Alam N, Singh V, Alam MS, Ali MS, Anwer T, Safhi MM. Type, preparation and evaluation of transdermal patch: a review. World Journal of Pharmacy and Pharmaceutical Sciences. 2013 May 21; 2(4): 2199-233.

10. Jatav VS, Saggu JS, Jat RK, SharmaAK, Singh RP. Recent advances in development of transdermal patches. Pharmacophore. 2011; 2(6-2011): 251-61

Received on 31.12.2025 Revised on 10.02.2026

Accepted on 12.03.2026 Published on 21.04.2026

Available online from April 24, 2026

Res. J. Pharma. Dosage Forms and Tech.2026; 18(2):155-162.

DOI: 10.52711/0975-4377.2026.00024

This work is licensed under a Creative Commons Attribution-Non Commercial-Share Alike 4.0 International License. Creative Commons License.

Type	Material	Structure	Use	Dose	Delivery Rate
Solid	Silicon, Metal, Polyme	Simple	Can be reuse	Small dose	Fast
Hollow	Silicon	Simple	Can be reuse	Large Dose	Fast
Coated	Polymer, Sugar, Lipids	Complex	Single	More precise dosing	Fast
Dissolving	Polymer	Complex	Single	More precise dosing	Slow