Many disorders of the anterior region of the eye may be efficiently treated via topical administration; however, it is more challenging to target conventional therapeutic doses to the posterior of the eye in this manner. Thus, various nanocarriers have been created and investigated for the transport of drugs and genes to the anterior or the posterior portions of the eyes. The most popular nano-drug delivery systems are depicted in Figure 1, and these can be utilized to increase the activity and bioavailability, and/or lessen the toxicity of the active pharmaceutical ingredients used. Liposomes, nanoparticles, micelles, inserts, implants, hydrogel, and emulsions are some of the most frequently utilized drug delivery systems.

Liposomes (Figure 1) are closed vesicles made of a phospholipid bilayer that can contain both drugs that are soluble in fat ^[1][313] and those that are soluble in water ^[2][314]. Due to their biodegradability, biocompatibility, and capacity to serve as drug carriers, liposomes have been thoroughly investigated for topical ocular administration (Table 1). Liposomes are particularly useful for large molecular weight and inadequately water-soluble drugs because they promote drug permeation through ocular tissues by virtue of their superior spreading ability and rheological properties that enable prolonging the drug availability on the surface of the eye ^[3][4][86,315]. Liposomes’ amphiphilic lipids form a tear compound-interacting sublayer when they make contact with tear lipid components. Polar heads and tails face the polar and non-polar tear lipid components, respectively, and help distribute the medication throughout the ocular surface ^[5][316]. Extensive research has examined the merits of liposomes for ocular use, minimizing potential drug toxicity and improving their absorption and bioavailability compared to an unencapsulated drug. These medications include vancomycin, tobramycin, ganciclovir, fluconazole, brinzolamide, triamcinolone acetonide, and cyclosporine A. Drug-loaded liposomal formulations injected intravitreally have a number of benefits. Some benefits include lengthening the half-life of drugs ^[6][317], safeguarding labile compounds ^[7][318], and prolonging the time that liposomes spend in the tissues of the eye ^[8][319].

Amphiphilic polymers can self-assemble into different structures, known as micelles (Figure 1). The formation of micelles within the nanometer range can efficiently improve the aqueous stability and enhance cell permeability. Prior research has demonstrated that the use of a nanomicelle formulation increased medication absorption in the eye ^[9][10][320,321]. Nanomicelle formulations are primarily used to improve the solubility of medications with low solubility and subsequently improve their bioavailability. Hesperidin, Sirolimus, Voriconazole, and Sunitinib are only a few of the medications that were made into polymeric nanomicelles with better solubility and therapeutic efficacy (Table 1).

Polymeric nanoparticles (Figure 1) could be produced by the use of naturally occurring or synthetically produced polymers. Chitosan, hyaluronic acid, carboxymethylcellulose sodium, albumin, and sodium alginate are some examples of natural polymers, whereas poly(lactic-co-glycolic acid), poly(-caprolactone), and poly(ethylene glycol) are examples of synthetic polymers ^[11][322]. Some retinal drugs are currently not performing as expected due to the physical and chemical properties of the medications, as well as the distinctive anatomical structure of the eye. The bioavailability of these drugs was significantly increased ^[12][323], their toxicity was reduced ^[13][324], invasive procedures could be avoided ^[14][325], and pharmacokinetic modulation was achieved ^[15][326] via incorporation into polymeric nanoparticles (Table 1). These drugs include dexamethasone, cyclosporin, latanoprost, voriconazole, and ganciclovir. Hyaluronic acid, polyethylene glycol, and chitosan are examples of mucoadhesive polymers that may be employed to alter nanoparticles to lengthen their pericorneal residence duration ^[16][327]. Moreover, mucus penetrating nanoparticles, which possess low surface tension, low viscosity, and higher hydration water content, can enhance the penetration of therapeutic medicines through the cornea, increasing their bioavailability and resulting in better pharmacologic results. Consequently, mucus penetrating nanoparticles may significantly improve the treatment of posterior ocular problems, which include posterior uveitis, CMV, and retinal disorders ^[17][328].

Lipids have been used to ameliorate the limited water solubility of several lipophilic drugs and adapt them as a drug delivery system ^[18][329]. Müller and Lucks initially developed solid lipid nanoparticles (SLNs, Figure 1) in 1996, which received the attention of scientists as a popular, stable, safe, and effective nanoscale drug delivery device. A surfactant layer that surrounds a solid lipid core in SLNs stabilizes and holds the medication ^[19][330]. Drug molecules can be found mostly in the center of particles or molecularly scattered throughout the matrix, depending on the drug solubility and the drug/lipid ratio ^[20][331]. SLNs are considered an efficient system intended for ocular drug delivery. SLNs can improve corneal drug absorptivity, enhance ocular tissue penetration and bioavailability, prolong residence time, and provide extended drug release properties ^[21][332]. SLNs were efficiently used to improve the delivery of bimatoprost ^[22][185], ofloxacin ^[23][333], and dorzolamide ^[24][334], as shown in Table 1.

Hydrogels (Figure 1) are produced when polymeric solutions are crosslinked to form a network. The hydrogel complexation is formed on the basis of hydrophilic interactions between the polymer tail and water molecules ^[25][335]. Hydrogels are widely employed to provide ocularly applied or injectable dosage forms to a variety of eye regions. For ocular application, there are various hydrogel formulations that have FDA approval. A hydrogel sealant called ReSure^® has been authorized for use in the non-operative treatment of clear corneal incisions. Hydrogels were also used to formulate and enhance the therapeutic activity of ocularly applied drugs, such as dexamethasone ^[26][336], bevacizumab ^[27][337], and timolol ^[28][338], as shown in Table 1.

Dendrimers (Figure 1) are globular, negatively, positively, or neutrally branch-like nanostructured polymers. They derive their net charge from the functional groups, which are located at the ends of their branches ^[29][339]. These molecules consist of a fundamental unit called the “core”, which comprises the major component, and side chain units called “dendrons” ^[30][340]. Drugs may be conjugated to the ligands on the dendrimer surface or may be retained in the dendrimer core. Dendrimer manufacturing, generation, surface characteristics, and conjugation technique all have an impact on the drug-loading and drug-release kinetics of dendrimers ^[31][341]. As a result of their ability to selectively target inflammatory cells while causing no harm to healthy tissue, dendrimers have proven to be a viable drug delivery vehicle for the treatment of inflammatory eye conditions. The capacity to lower medication toxicity off-target is the key advantage of dendrimers’ targeting abilities ^[32][153]. Utilizing dendrimers effectively can increase the therapeutic effectiveness of various active pharmaceutical compounds (Table 1), including pilocarpine ^[33][241], tropicamide ^[33][241], dexamethasone ^[34][342], brimonidine, and timolol ^[35][343].

Nanocrystals (Figure 1) are crystals of therapeutic drugs with particle sizes as small as a few hundred nanometers, where pure drug crystals may occasionally be stabilized by the addition of surface active agents or polymeric solutions ^[36][344]. The benefits of nanocrystals over conventional nanocarriers, such as their high drug payload and comparative ease of manufacture, make them appealing candidates for the delivery of medications that are not readily water soluble ^[37][38][345,346]. The preparation of therapeutic drugs in the form of nanocrystals for ocular administration has various advantages. These advantages include better tolerability, increased ocular absorption, providing intermediated and prolonged release of drugs in the eye, and improved ocular permeation ^[39][347]. They also include improved ocular safety, increased formulation retention in cul-de-sac, and enhanced ocular permeation ^[40][152]. A number of medications used ocularly have been transformed into nanocrystals (Table 1) with enhanced properties, and these include dexamethasone ^[41][348], itraconazole ^[42][349], tedizolid ^[43][350], and brinzolamide ^[44][227]. Moreover, Novartis Pharmaceutical Corporation’s formulation of nepafenac nanocrystals received approval for commercial release (FDA, 2012) under the brand name Ilevro^®.

Cubosomes (Figure 1) are made up of two inner aqueous pathways that are separated into two arched interpenetrating lipid bilayers, which are structured in three dimensions resembling honeycombs ^[45][351]. These pathways can be occupied by a variety of bioactive molecules, including natural bioactives, chemical pharmaceuticals, peptides, polypeptides, and proteins ^[46][352]. Cubosomes are thought to be promising delivery systems because of their special characteristics, including thermodynamic stability, bioadhesion, the capacity to encapsulate different types of drugs, and their potential to control drug release ^[47][353]. Active medicines and macromolecules can successfully be applied topically to the posterior portion of the eye using cubosomes (Table 1). These drugs include beclomethasone ^[46][352], flurbiprofen ^[48][354], timolol ^[49][199], and brimonidine ^[50][355].

Niosomes, which are a type of vesicular system that includes a non-ionic surfactant, are closed bilayer structures produced once the nonionic surfactants self-assemble in an aqueous media to create nanocarriers (Figure 1). Researchers have begun using niosomal systems to treat severe inflammatory diseases and conditions, such various malignancies, because of their potential to boost the bioavailability and efficiency of the encapsulated therapeutics ^[51][356]. Niosomes are being investigated more and more for improving drug delivery to both segments of the eye, anterior and posterior, as well as promoting drug penetration and retention in ocular tissues. As a consequence, niosomes showed a considerable increase in the absorption and transcorneal permeability of topically applied drugs at the ocular surface (Table 1). These drugs include cyclopentolate ^[52][357], voriconazole ^[53][358], acetazolamide ^[54][359], gentamicin ^[55][360], brinzolamide ^[56][361], pilocarpine ^[57][362], and tacrolimus ^[58][363]. Additionally, niosomes, particularly charged vesicles, have been effectively used to transfer genes by subretinal or intravitreal injection to the retinal area ^[59][364].

An emulsion (Figure 1) is a uniform dispersion system that is formed upon mixing two or more immiscible liquids under certain circumstances ^[60][365]. Lipid-based emulsions have become a potential vehicle for ocular medication administration. The emulsions enhance ocular delivery using one of two major strategies, either by improving ocular permeability or by lengthening the period the formulation is retained on the ocular surface ^[61][366]. Both hydrophilic and lipophilic drug types may be loaded into emulsions ^[62][63][367,368]. Emulsions have been successfully used to create more effective formulations for several medications used intraocularly that have increased absorption and therapeutic effectiveness. These drugs include cyclosporine A ^[64][369], coumarin-6 ^[65][370], azithromycin, and disulfiram ^[66][371].

One type of vesicular drug delivery system is the bilosome (Figure 1), which is made up of non-ionic amphiphilic compounds with integrated bile salt molecules. The negatively charged bile salts serve to maintain the bilosomal structure ^[67][372]. In comparison to niosomes and liposomes, these drug carriers are more stable and can effectively increase drug absorption through biological membranes ^[68][373]. Moreover, bilosomes can enhance the permeability of polysaccharides, proteins, and polypeptides, which are poorly transported through mucosal epithelial cells ^[69][374]. Previous research studies have assessed the effectiveness of bilosomes in the administration of ocular drugs (Table 1) and found that bilosomes are well tolerated by corneal tissues ^[70][236]. These drugs include terconazole ^[71][375], acetazolamide ^[70][236], ciprofloxacin ^[72][376], ciprofloxacin ^[72][376], agomelatine ^[73][377], and betaxolol ^[74][211].

Nanocapsules (Figure 1) are a subtype of nanoparticles that are comparable to vesicular systems, in which a medicine is contained in a hollow vessel with an inner liquid core encircled by a polymeric coating ^[75][378]. Nanocapsules are well-known to be retained in the cornea for a prolonged time and to enhance penetration throughout the deep ocular tissues ^[40][152]. Thus, the development of topically applied drug-loaded nanocapsules could reduce uncomfortable intravitreal injections and systemic delivery, which have serious side effects ^[40][152]. The therapeutic action of several medications was effectively potentiated via formulation in the form of nanocapsules (Table 1). These drugs include bevacizumab ^[76][379], prednisolone ^[77][165], tacrolimus ^[40][152], brinzolamide ^[44][227], and cyclosporine ^[78][380].

Elastic niosomes, also known as spanlastics (Figure 1), are a subtype of vesicular drug delivery systems that are relatively new to the market. They resemble niosomes (non-ionic surfactant vesicles), except they contain an edge activator. They were first described as systems for ocular drug delivery ^[79][381], but since then, they have been used to deliver medications to a variety of bodily organs. The spanlastics’ bilayers become more elastic and deformable when an edge activator is present, which improves drug absorption across biological membranes. Spanlastics were efficiently used to payload hydrophilic, hydrophobic, and amphiphilic therapeutic pharmaceuticals for ocular use, especially the delivery to the posterior segment (Table 1). These drugs include ketoconazole ^[79][381], cyclosporine A ^[80][382], clotrimazole ^[81][383], and vanillic acid ^[82][384].

Disease	Treatment		Drug	Delivery System Platform	Advantages of Delivery Systems In Vivo	Refs.
Dry eye syndrome	Tear substitutes		Hypromellose	Solution		[83][126]
			Methylcellulose and derivatives	Solution		[84][127]
			hyaluronic acid	Solution		[85][128]
	Aqueous secretagogues		Diquafosol sodium	Solution		[86][129]
	Punctal plugs		Collagen and atelocollagen	In situ hydrogel	Prolonged activity	[87][88][89][49,50,130]
			methacrylate-modified silk fibroin	In situ hydrogel	Prolonged activity	[90][54]
	Mucin secretagogues		Rebamipide	Nanoparticles	Sustained release	[91][131]
				Liposomes	Improved activity	[92][132]
				Micelles	Improved penetration	[93][133]
	Anti-inflammatory and immunomodulatory drugs		Cyclosporine	Micelles	Improved activity	[94][134]
				Self-nanoemulsifying	Improved efficacy	[95][135]
				Liposomes	Improved activity	[96][136]
				Nanoparticles	Improved activity	[97][137]
				Nano-emulsion	Improved penetration	[98][138]
				Solid lipid nanoparticles	Controlled release	[99][139]
				In situ hydrogel	Improved activity	[94][134]
			Epigallocatechin gallate	Nanoparticles	Extended activity	[100][140]
				In situ gels	Enhanced efficacy	[101][141]
			Lactoferrin	Nanoparticles	Enhanced efficacy	[102][142]
				Nanocapsules	Controlled release	[103][143]
				Liposomes	Reduced irritation	[104][144]
				Nanostructured lipid carriers	Controlled release	[105][145]
			Vitamin A	Liposomes	Improved activity	[106][146]
			Tacrolimus	Nanoparticles	Improved penetration	[107][147]
				Progylcosomes	Improved activity	[108][148]
				Microcrystals	Improved efficacy	[109][149]
				Liposomes	Improved retention time	[110][150]
				Micelles	Prolonged activity	[111][151]
				Nanocapsules	Improved activity	[40][152]
	Corticosteroids		Dexamethasone	Dendrimer	Improved activity	[32][153]
				Nano-wafer	Improved activity	[112][154]
				Nanostructured lipid carriers	Improved activity	[113][155]
				Nanoparticles	Improved penetration	[114][156]
				Micelles	Release modulation	[115][157]
				Nanosuspension	Prolonged activity	[116][158]
				Nano emulsion	Improved activity	[117][159]
				Nanosponges	Improved permeability	[118][160]
			Fluorometholone	Nanoparticles	Improved activity	[119][161]
			Triamcinolone acetonide	Micelles	Release modulation	[120][60]
				Nanoparticles	Improved activity	[121][162]
			Hydrocortisone	Nanosuspension	Prolonged activity	[116][158]
				Micelles	Improved targeting	[122][163]
				Nanoparticles	Improved penetration	[122][163]
				Nanosuspension	Prolonged activity	[116][158]
			Prednisolone	Nanoparticles	Prolonged activity	[123][164]
				Nano capsules	Reduced toxicity	[77][165]
			Lotep rednol etabonate	Nanoparticles	Improved penetration	[124][166]
	Non-steroidal anti-inflammatory drugs		Diclofenac sodium	Nanoparticles	Improved bioavailability	[125][167]
				Nanosuspension	Prolonged activity	[126][168]
			Pranoprofen	Nanosuspension	Improved activity	[127][169]
				Nanoparticles	Improved activity	[127][128][169,170]
			Bromfenac sodium	Liposomes	Extended release	[129][171]
				Nanoparticles	Improved permeation	[130][172]
				Cubosomes	Improved bioavailability	[131][61]
			Ketorolac	Nanoparticles	Improved delivery	[132][173]
	lymphocyte function-associated antigen-1 antagonists		Lifitegrast	Solution		[133][134][174,175]
Glaucoma	Prostaglandin analogues		Latanoprost	Nanoparticles	Controlled release	[135][176]
				PEGylated solid lipid	Improved permeability	[136][177]
				Micelles	Extended release	[137][178]
				Cubosomes	Sustained release	[138][179]
				Nanoparticles	Improved permeability	[139][180]
			Travoprost	Gold nanoparticles	Improved stability	[140][181]
				Liposomes	Sustained release	[141][182]
				Spanlastics	Prolonged activity	[142][183]
				Nanoemulsion	Improved pharmacokinetics	[143][75]
				Implant	Controlled release	[144][184]
			Bimatoprost	Nanoparticles	Improved therapeutic activity	[22][185]
				Gold nanoparticles	Controlled release	[145][186]
				Nanoparticle hydrogel	Controlled release	[146][187]
				Microemulsion	Improved permeability	[147][188]
				Graphene oxide-laden	Controlled release	[148][189]
				Implants	Sustained release	[149][190]
				Nanovesicular systems	Sustained release	[150][191]
				Inserts	Extended release	[151][192]
			Unoprostone	Transscleral device	Sustained release	[152][193]
	Rho kinase inhibitors		Fasudil	Liposomes	Enhanced bioavailability	[153][194]
				Microspheres	Sustained release	[154][195]
			Ripasudil	Solution		[155][196]
			Netarsudil	Solution		[156][197]
	β-adrenergic blockers		Timolol	Nanoparticles	Extended release	[157][198]
				Micelles	Extended release	[137][178]
				Cubosomes	Improved bioavailability	[49][199]
				Nanogel	Sustained release	[158][200]
				Gelatinized core liposomes	Improved encapsulation	[159][201]
				Microemulsion	Improved bioavailability	[160][202]
			Levobunolol	Nanoparticles	Extended release	[161][203]
				Microparticles	Sustained release	[162][76]
			Carteolol	Nanocapsules	Improved activity	[163][204]
				Nanoparticles	Improved activity	[164][205]
				Chitosomes	Improved penetration	[165][206]
			Metipranolol	Nanocapsules	Reduced systemic side effects	[166][207]
			Betaxolol	Liposomes	Extended activity	[167][208]
				Nanoparticles	Controlled release	[168][209]
				Niosomes	Improved bioavailability	[169][210]
				Bilosomes	Improved transcorneal permeation	[74][211]
	α-adrenergic agonists		Brimonidine	Nanoparticles	Sustained release	[170][212]
				Inserts	Controlled release	[171][213]
				Niosomes	Sustained release	[172][214]
				Microspheres	Sustained release	[173][215]
				Liposomes	Improved effectiveness	[174][216]
				Implant	Sustained release	[175][217]
				Gelatin-core liposomes	Improved drug loading	[176][77]
	Carbonic anhydrase inhibitors		Dorzolamide	Nanoparticles	Improved activity	[177][218]
				Nanoemulsion	Enhanced ocular delivery	[178][219]
				Liposomes	Prolonged action	[179][78]
				Microparticles	Sustained release	[180][220]
				Niosomes	Improved activity	[181][221]
				Implant	Extended drug delivery	[182][222]
				Inserts	Improved activity	[183][223]
			Brinzolamide	Nanoparticles	Improved therapeutic activity	[184][224]
				Nanocrystals	Improved penetration	[185][225]
				Liposomes	Sustained release	[186][226]
				Nanocapsules	Improved bioavailability	[44][227]
				Nanoemulsion	Improved therapeutic efficacy	[187][228]
				Nanofibers	Improved patient compliance	[188][229]
				Implant	Sustained release	[189][230]
			Acetazolamide	Cubosomes	Improved therapeutic efficacy	[190][231]
				Spanlastics	Enhanced ocular delivery	[191][232]
				Transgelosomes	Enhanced ocular delivery	[192][233]
				Implants	Sustained release	[193][234]
			Niosomes	Improved permeability	[194][235]
			Bilosomes	Improved permeability	[70][236]
			Microsponges	Improved therapeutic efficacy	[195][237]
			Dendrimers	Sustained release	[196][238]
Cholinergic agonists		Pilocarpine	Nanoparticles	Sustained release	[197][239]
			Nanocapsules	Improved bioavailability	[198][240]
			Dendrimers	Prolonged residence time	[33][241]
Uveitis	Corticosteroids		Fluocinolone acetonide	Implant (Retisert®)	Sustained release	[199][242]
				Nanoparticles	Improved bioavailability	[200][243]
			Difluprednate	Microneedles	Sustained release	[201][244]
			Fluormetholone	Nanoparticles	Improved penetration	[202][245]
				Nanocrystals	Improved sustained activity	[203][246]
			Triamcinolone acetonide	Nano lipid carriers	Improved penetration	[204][247]
	Immunomodulator drugs		Adalimumab	Hydrogel	Improved permeability	[205][248]
			Infliximab	Liposomes	Prolonged activity	[206][249]
			Methotrexate	Implant	Sustained release	[207][250]
			Sirolimus (Rapamycin)	Implant	Extended release	[208][251]
				Micelles	Sustained release	[209][252]
				Exosomes	Improved therapeutic activity	[210][253]
				Liposomes	Improved therapeutic activity	[3][86]
Endophthalmitis	Antimicrobials		Daptomycin	Nanoparticles	Noninvasive and improved activity	[211][254]
			Vancomycin	Nanostructured lipid carriers	Improved permeability and activity	[212][255]
				Nanoparticles	Sustained release	[213][256]
				Thermoresponsive hydrogels	Controlled release	[214][257]
				Liposomes	Improved permeability	[215][258]
				Implant	Controlled release	[216][259]
				Niosomes	Improved permeability	[217][260]
			Ceftazidime	Nanoparticles	Improved activity and permeability	[218][261]
	Antifungals		Amphotericin B	Liposomes	Improved activity-reduce toxicity	[219][262]
			Voriconazole	Thermo-sensitive in situ gel	Sustained release	[220][263]
				Nanoparticles	Improved permeability	[221][264]
				Microemulsion	Controlled release	[222][265]
				Elastosomes	Improved activity and reduced toxicity	[223][266]
				Micelles	Improved stability	[223][266]
				Liposomes	Improved permeability	[224][267]
	Antivirals		Cidofovir	Micelles	Prolonged activity	[225][268]
				Liposomes	Prolonged activity	[226][269]
			Foscarnet	Liposomes	Improved activity and permeability	[227][270]
			Ganciclovir	Nanoparticles	Sustained release	[228][271]
				Glycerosomes	Sustained release	[229][272]
				Microemulsion	Improved permeability	[230][273]
				Vitrasert	Prolonged activity	[231][274]
				Minitablets	Sustained release	[232][275]
Retinal diseases	Age-related macular degeneration	Anti-VEGF Agents	Ranibizumab	Nanoparticles	Improved activity	[233][276]
			(Antibody fragment)	Microparticles	Improved intravitreal delivery	[234][277]
				Liposomes	Increased encapsulation-release	[235][278]
				Quantum dots	Sustained release	[236][279]
				Implant	Sustained release	[237][280]
			Bevacizumab	Nanoparticles	Sustained delivery	[238][281]
			(Monoclonal antibody)	Bi-layered capsule	Sustained delivery	[239][282]
				Nanocapsules	Improved bioavailability	[240][283]
				Implant	Sustained release	[241][284]
				Microparticles	Sustained release	[242][285]
				Liposomes	Sustained release	[243][286]
			Aflibercept (VEGF-Trap)	Nanoparticles	Sustained drug release	[244][287]
				Microspheres	Extended release	[245][288]
			Sunitinib	Nanoparticles	Superior prolonged activity	[246][289]
				Micelles	Extended release	[247][290]
			Axitinib	Nanoparticles	Superior activity	[248][291]
			Pegaptanib	PEGylated aptamer	Prolonged activity	[249][113]
		Gene therapy	VEGF-siRNA	Liposomes	Improved activity-stability	[250][292]
				Nanoball	Improved activity-targeting	[251][293]
				Nanoparticles	Improved therapeutic activity	[252][294]
		Integrin antagonists	C16Y peptide	Nanoparticles	Sustained release	[253][295]
		Antioxidants	Serine-threonine-tyrosine peptide	Nanoparticles	Targeting	[254][296]
			Resveratrol	Nanoparticles	Sustained release	[255][297]
			Curcumin	Liposomes	Improved activity	[256][298]
			Astragaloside	Nanocapsules	Improved activity	[257][299]
	Diabetic retinopathy	Antiangiogenics	Anti-Flt1 peptide	Nanoparticles	Sustained release	[258][300]
				Micropump implant	On-demand targeting	[259][301]
			Fenofibrate	Nanoparticles	Controlled release	[260][302]
			Pioglitazone	Nanoparticles	Controlled/improved activity	[261][303]
			Apatinib	Nanoparticles	Improved activity	[262][304]
			Silicate	Nanoparticles	Improved activity	[263][305]
			Tacrolimus	Nanoparticles	Improved activity	[264][306]
			Sorafenib tosylate	Nanoparticles	Improved activity	[265][307]
			Octreotide	Nanoparticles	Improved activity-targeting	[266][308]
		Anti-inflammatory and antioxidants	p-Coumaric acid	Nanoparticles	Improved activity	[267][309]
			Connexin43 mimetic peptide	Nanoparticles	Targeting	[268][310]
			Inulin D α-tocopherol succinate	Nanomicelles	Improved activity	[269][311]
			Citicoline	Liposomes	Improved permeation	[270][312]
			Melatonin	Nanoparticles	Controlled release and enhanced tolerability	[270][312]