. 2021 Oct 8;13(10):1637. doi: 10.3390/pharmaceutics13101637

Table 2.

Ocular inserts formulations and base types.

Drug (Concentration)	Applied Polymer Base	Type of Base (Soluble/Insoluble/Erodible)	Effect/Aim	References
Azithromycin (20% w/w)	Hydroxypropylmethyl cellulose (HPMC) and Eudragit RL100	Erodible	To prolong release and improve ocular availability	[10]
Azithromycin (20% w/w)	Hydroxypropylmethyl cellulose (HPMC) and Eudragit RL100	Erodible	Release: over 12 h	[10]
Triamcinolone acetonide (0.5% w/w)	Poly(1,4-butylene succinate) extended with 1,6-diisocyanatohexane (PBS)	Insoluble	Non-erodible mucoadhesive to sustain release	[34]
Triamcinolone acetonide (0.5% w/w)		Insoluble	Release of active for 30 days	[34]
Azithromycin (10% w/w)	Hydroxypropyl methylcellulose (HPMC) or hydroxyethyl cellulose (HEC).	Soluble and erodible	Polymeric inserts to sustain drug release	[59]
Azithromycin (10% w/w)		Soluble and erodible	Significantly prolonged release of AZM in rabbit eyes (121 h)	[59]
Cetirizine (7.5% w/v)	Hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA)	Soluble and erodible	To ensure sustained drug release and increased residence time	[60]
Cetirizine (7.5% w/v)		Soluble and erodible	210 min	[60]
Ofloxacin (1.5 and 6% w/w)	Poly(ethylene oxide) (PEO 400 or PEO 900)	Erodible	To be able to release different drugs of interest in ophthalmology	[61]
Besifloxacin HCl (40 μg/ ${cm}^{2}$ )	Poly(caprolactone)/polyethylene glycol (PLC/PEG) (2:1)	Erodible	To reduce application frequency and increase patient compliance	[33]
Besifloxacin HCl (40 μg/ ${cm}^{2}$ )	Poly(caprolactone)/polyethylene glycol (PLC/PEG) (2:1)	Erodible	7 days	[33]
Dorzolamide HCl (0.37% w/v)	Polyvinyl alcohol, poloxamer 407	Soluble	Comparative result shows that dorzolamide HCL soluble insert was more effective than marketed formulation	[62]
Timolol maleate (TM) (0.5% w/v)	Hyaluronic acid (HA) and hydroxypropyl methylcellulose (HPMC)	Erodible	To enhance drug retention on ocular surface and potentially improve bioavailability	[63]
Moxifloxacin hydrochloride (5% w/w)	Eudragit™ FS-100 (FS) and propylene glycol (PG)	Soluble	To provide a once-a-day application as an alternative delivery system in management of bacterial infections	[64]
Gatifloxacin (2.4 mg/78.5 mm²)	Thiolated sodium alginate (TSA), sodium alginate (SA), and acrylates: ERL:ERS (75:25)	Erodible	Inserts for twice-a-day therapy with gatifloxacin	[65]
Dexamethasone (1%, 5% and 10% w/w)	Polylactic acid (PLA) and poly-vinyl alcohol (PVA)	Erodible	Nanofibrous inserts were better than solvent cast inserts and could be utilized as a potential delivery system for treating anterior segment ocular diseases	[52]
Curcumin (1% w/w)	Carboxymethylcellulose (CMC), polyvinyl alcohol, hydroxypropyl methylcellulose	Soluble	Developed inserts demonstrated acceptable ocular tolerability, enhanced corneal permeability, and sustained release	[66]
Lysozyme (3% w/w)	Hydroxypropyl methylcellulose (HPMC)	Erodible	Novel drug delivery system (DDS) with sustained release properties was developed to allow ocular protein delivery	[67]
Gentamicin sulfate (25.0% w/w)	Mixture of hydroxypropyl cellulose, ethyl cellulose, poly(acrylic) acid	Soluble	Inserts ensured effective gentamicin levels over 72 h	[68]
Indomethacin (IN; 10% w/w), prednisolone sodium phosphate (PSP; 10% w/w), ciprofloxacin hydrochloride (CIP; 10% w/w)	Polyethylene oxide (PEO) N10	Erodible	Noninvasive ocular inserts for posterior segment	[69]
			Trans-membrane flux of IN, prednisolone sodium phosphate, and ciprofloxacin hydrochloride was enhanced by ~3.5, ~3.6, and ~2.9-fold, respectively
			Ocular inserts generated significantly higher drug levels in all ocular tissues, including retina-choroid, compared with control formulations
Valacyclovir HCl (20% w/w)	HPC and HPMC	Soluble and erodible	Ocular inserts showed improved flux compared with control formulation	[70]
Valacyclovir HCl (20% w/w)	HPC and HPMC	Soluble and erodible	Ocular inserts dissolved completely within 8 h	[70]
Fluorescein (3% w/w), lysozyme (3% w/w), albumin (3% w/w)	HPMC	Erodible	Ophthalmic inserts with sustained release properties as carriers for thermo-labile therapeutics	[71]
Gentamicin sulfate (25.0% w/w), dexamethasone phosphate (5.0 and 25% w/w)	Hydroxypropyl cellulose (HPC)	Soluble	New system ensures concomitant release of drugs during first 10 h of treatment, followed by adequate concentration of gentamicin sulfate	[72]
Ketorolac tromethamine (KT; 1% w/v)	Eudragit S100 and Zein	Erodible	Ocular delivery system using electrospun nanofibers as candidate insert for delivery of triamcinolone acetonide	[38]
Ketorolac tromethamine (KT; 1% w/v)	Eudragit S100 and Zein	Erodible	To improve bioavailability	[38]
Ofloxacin (3–9% w/w)	Chitosan/polyvinyl alcohol (CS/PVA), Eudragit RL100.	Erodible	To enhance ocular residence time of ofloxacin	[58]
Ofloxacin (3–9% w/w)	Chitosan/polyvinyl alcohol (CS/PVA), Eudragit RL100.	Erodible	Sustained release pattern up to 96 h	[58]
Brimonidine tartrate (≈10–30% w/w)	PEO with Eudragit (RL 100/RS 100)	Erodible	To design mucoadhesive and extended release ocular inserts; up to 24 h	[73]
Linezolid (LNZ; 0.2% w/v)	Modified sodium alginate-grafted poly (butyl methacrylate) and sodium alginate-grafted poly (lauryl methacrylate)	Erodible	Polymeric thin films with increased ocular residence time and sustained drug release capacity	[74]