A COMPREHENSIVE REVIEW ON IN SITU GELS
DOI:
https://doi.org/10.22159/ijap.2020v12i6.38918Keywords:
Gels, Hydrogels, In situ gel, Polymers, Gelling mechanismAbstract
The current review on in situ gelling systems becomes one of the most popular and prominent. It had a tremendous potential advantage of delivery systems due to many benefits like easy to use simple manufacturing; improve both adherence and patient comfort by minimizing the frequency of drug administration by its unique characteristics feature of sol to gel transition. It also provides in situ gelling nanoemulsions, nanosphere, microspheres, and liposomes. The drawbacks associated with conventional systems of both solutions and gels, such as accurate dosing, ease of administration overcome by using in situ gelling systems. This review focused on definitions, types, advantages, disadvantages, polymers used, and suitable characteristics of polymers, including the preparation of in situ gels covered in the introduction. Approaches, applications, and evaluation of in situ gels were explained with examples.
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Rogovina LZ, Vasilev VG, Braudo EE. Definition of the concept of the polymer gel. Polym Sci Series C 2008;50:85-92.
Whitlock DR, Weiss L, Ambrogio LN, Inventors, AOBIOME LLC, Assignee. Ammonia oxidizing microorganisms for use and delivery to the gastrointestinal system. United States patent application US 16/318,583; 2019.
Carlfors J, Edsman K, Petersson R, Jornving K. Rheological evaluation of gelrite in situ gels for ophthalmic use. Eur J Pharm Sci 1998;6:113-9.
Ullah F, Othman MB, Javed F, Ahmad Z, Akil HM. Classification, processing and application of hydrogels: a review. Mater Sci Eng C 2015;57:414-33.
Crini G. Recent developments in polysaccharide-based materials used as adsorbents in wastewater treatment. Prog Polym Sci 2005;30:38-70.
Kuo CK, Ma PX. Ionically cross-linked alginate hydrogels as scaffolds for tissue engineering: part 1. Structure, gelation rate and mechanical properties. Biomaterials 2001;22:511-21.
Peak CW, Wilker JJ, Schmidt G. A review on tough and sticky hydrogels. Colloid Polym Sci 2013;291:2031-47.
Fuchs S, Shariati K, Ma M. Specialty tough hydrogels and their biomedical applications. Adv Healthcare Mater 2020;9:1901-396.
Zhao X, Sun X, Zhang J, Bai B. Gel composition and brine concentration effect on hydrogel dehydration subjected to uniaxial compression. J Petrol Sci Eng 2019;182:106358.
Bai B, Zhou J, Yin M. A comprehensive review of polyacrylamide polymer gels for conformance control. Petrol Explor Dev 2015;42:525-32.
Prashar A. Shed tears for diagnostics. Springer Singapore; 2019.
Sarada K, Firoz S, Padmini K. In-situ gelling system: a review. Int J Curr Pharma Rev Res 2014;15:76-90.
Bhardwaj L, Sharma PK, Malviya R. A short review on gastro-retentive formulations for stomach specific drug delivery: special emphasis on floating in situ gel systems. Afr J Basic Appl Sci 2011;3:300-12.
Prabaharan M, Mano JF. Chitosan-based particles as controlled drug delivery systems. Drug Delivery 2004;12:41-57.
Kaur P, Garg T, Rath G, Goyal AK. In situ nasal gel drug delivery: A novel approach for brain targeting through the mucosal membrane. Artificial Cells Nanomed Biotech 2016;44:1167-76.
Browning TR, Heath RD. Reconceptualizing the effects of lean on production costs with evidence from the F-22 program. J Operations Management 2009;27:23-44.
Dai T, Huang YY, K Sharma S, T Hashmi J, B Kurup D, R Hamblin M. Topical antimicrobials for burn wound infections. Recent Pat Anti-infect Drug Discovery 2010;5:124-51.
Figueira RB, Silva CJ, Pereira EV. Organic–inorganic hybrid sol–gel coatings for metal corrosion protection: a review of recent progress. J Coat Technol Res 2015;12:1-35.
Kumar A, Srivastava A, Galaev IY, Mattiasson B. Smart polymers: physical forms and bioengineering applications. Prog Polym Sci 2007;32:1205-37.
Mishra M, Kumar P, Rajawat JS, Malik R, Sharma G, Modgil A. Nanotechnology: revolutionizing the science of drug delivery. Curr Pharm Des 2018;24:5086-107.
Langmaier F, Mokrejs P, Kolomaznik K, Mladek M. Biodegradable packing materials from hydrolysates of collagen waste proteins. Waste Management 2008;28:549-56.
HB N, Bakliwal SR, Pawar SP. In-situ gel: new trends in controlled and sustained drug delivery system. Inter J Pharm Tech Res 2010;2:1398-408.
Jadhav UG, Dias RJ, Mali KK, Havaldar VD, Additional MI. Development of in situ-gelling and mucoadhesive liquid suppository of ondansetron. Int J Chem Tech Res 2009;1:953-61.
Packhaeuser CB, Schnieders J, Oster CG, Kissel T. In situ forming parenteral drug delivery systems: an overview. Eur J Pharm Biopharm 2004;58:445-55.
Hatefi A, Amsden B. Biodegradable injectable in situ forming drug delivery systems. J Controlled Release 2002;80:9-28.
Lin Z, Gao W, Hu H, Ma K, He B, Dai W, et al. Novel thermo-sensitive hydrogel system with paclitaxel nanocrystals: high drug-loading, sustained drug release and extended local retention guaranteeing better efficacy and lower toxicity. J Controlled Release 2014;174:161-70.
Malik K, Singh I, Nagpal M, Arora S. Atrigel: a potential parenteral controlled drug delivery system. Pharm Sin 2010;1:74-81.
Jeong B, Kim SW, Bae YH. Thermosensitive sol–gel reversible hydrogels. Adv Drug Delivery Rev 2012;64:154-62.
Baldwin AD, Kiick KL. Polysaccharide‐modified synthetic polymeric biomaterials. Pept Sci: Original Res Biomolecules 2010;94:128-40.
Grassin Delyle S, Buenestado A, Naline E, Faisy C, Blouquit Laye S, Couderc LJ, et al. Intranasal drug delivery: an efficient and non-invasive route for systemic administration: focus on opioids. Pharmacol Ther 2012;134:366-79.
Soppimath KS, Aminabhavi TM, Kulkarni AR, Rudzinski WE. Biodegradable polymeric nanoparticles as drug delivery devices. J Controlled Release 2001;70:1-20.
Jothi M, Harikumar SL, Aggarwal G. In-situ ophthalmic gels for the treatment of eye diseases. Inter J Pharm Sci Res 2012;3:1891.
Almeida H, Amaral MH, Lobao P, Lobo JM. In situ gelling systems: a strategy to improve the bioavailability of ophthalmic pharmaceutical formulations. Drug Discover Today 2014;19:400-12.
Ruel Gariepy E, Leroux JC. In situ-forming hydrogels-review of temperature-sensitive systems. Euro J Pharm Bio-Pharm 2004;58:409-26.
Singh NK, Lee DS. In situ gelling pH-and temperature-sensitive biodegradable block copolymer hydrogels for drug delivery. J Controlled Release 2014;193:214-27.
Kempe S, Mader K. In situ forming implants-an attractive formulation principle for parenteral depot formulations. J Controlled Release 2012;161:668-79.
Sudhakar Y, Kuotsu K, Bandyopadhyay AK. Buccal bio-adhesive drug delivery-a promising option for orally less efficient drugs. J Controlled Release 2006;114:15-40.
Nagarwal RC, Kant S, Singh PN, Maiti P, Pandit JK. Polymeric nanoparticulate system: a potential approach for ocular drug delivery. J Controlled Release 2009;136:2-13.
Hoare TR, Kohane DS. Hydrogels in drug delivery: progress and challenges. Polym 2008;49:1993-2007.
Gu D, O’Connor AJ, GH Qiao G, Ladewig K. Hydrogels with smart systems for delivery of hydrophobic drugs. Expert Opin Drug Delivery 2017;14:879-95.
Abdelkader H, Mansour HF. Comparative studies for ciprofloxacin hydrochloride preformed gels and thermally triggered (in situ) gels: in vitro and in vivo appraisal using a bacterial keratitis model in rabbits. Pharm Dev Technol 2015;20:410-6.
Kumbhar AB, Rakde AK, Chaudhari PD. In situ gel forming injectable drug delivery system. Int J Pharm Sci Res 2013;4:597-609.
Mundada AS, Avari JG. In situ gelling polymers in ocular drug delivery systems: a review. Crit Rev Ther Drug Carrier Syst 2009;26:85-118.
Mahajan HS, Shah SK, Surana SJ. Nasal in situ gel containing hydroxy propyl β-cyclodextrin inclusion complex of artemether: development and in vitro evaluation. J Incl Phenom Macrocycl Chem 2011;70:49-58.
Singh RM, Kumar A, Pathak K. Mucoadhesive in situ nasal gelling drug delivery systems for modulated drug delivery. Expert Opin Drug Delivery 2013;10:115-30.
Matanovic MR, Kristl J, Grabnar PA. Thermoresponsive polymers: insights into decisive hydrogel characteristics, mechanisms of gelation, and promising biomedical applications. Inter J Pharm 2014;472:262-75.
Coviello T, Matricardi P, Marianecci C, Alhaique F. Polysaccharide hydrogels for modified release formulations. J Controlled Release 2007;119:5-24.
Malafaya PB, Silva GA, Reis RL. Natural–origin polymers as carriers and scaffolds for biomolecules and cell delivery in tissue engineering applications. Adv Drug Delivery Rev 2007;59:207-33.
Gil ES, Hudson SM. Stimuli-responsive polymers and their bio-conjugates. Prog Polym Sci 2004;29:1173-222.
Gulrez SK, Al-Assaf S, Phillips GO. Hydrogels: methods of preparation, characterisation and applications. Progress in molecular and environmental bioengineering from analysis and modelling to technology applications; 2011. p. 117-50.
Brinker CJ, Scherer GW. Sol-gel science: the physics and chemistry of sol-gel processing. Academic Press; 2013.
Radivojsa M, Grabnar I, Grabnar PA. Thermo-reversible in situ gelling poloxamer-based systems with chitosan nanocomplexes for prolonged subcutaneous delivery of heparin: design and in vitro evaluation. Eur J Pharm Sci 2013;50:93-101.
Devasani SR, Dev A, Rathod S, Deshmukh G. An overview of in situ gelling systems. Pharm Biological Eva 2016;3:60-9.
Parekh HB, Jivani R, Jivani NP, Patel LD, Makwana A, Sameja K. Novel in situ polymeric drug delivery system: a review. J Drug Delivery Ther 2012;2:136-45.
Liu L, Gao Q, Lu X, Zhou H. In situ forming hydrogels based on chitosan for drug delivery and tissue regeneration. Asian J Pharm Sci 2016;11:673-83.
Saini R, Saini S, Singh G, Banerjee A, Railmajra DS. In situ gels-a new trends in ophthalmic drug delivery systems. Int J Pharm Sci Res 2015;6:386-90.
Brun Graeppi AK, Richard C, Bessodes M, Scherman D, Merten OW. Thermoresponsive surfaces for cell culture and enzyme-free cell detachment. Prog Polym Sci 2010;35:1311-24.
Darge HF, Andrgie AT, Tsai HC, Lai JY. Polysaccharide and polypeptide based injectable thermo-sensitive hydrogels for local biomedical applications. Inter J Biol Macromol 2019;133:545-63.
Taylor MJ, Tomlins P, Sahota TS. Thermo-responsive gels. Gels 2017;3:4.
Jagur Grodzinski J. Polymeric gels and hydrogels for biomedical and pharmaceutical applications. Polym Adv Technol 2010;21:27-47.
Cole MA, Voelcker NH, Thissen H, Griesser HJ. Stimuli-responsive interfaces and systems for the control of protein–surface and cell-surface interactions. Biomaterials 2009;30:1827-50.
He C, Kim SW, Lee DS. In situ gelling stimuli-sensitive block copolymer hydrogels for drug delivery. J Controlled Release 2008;127:189-207.
Masteikova R, Chalupova Z, Sklubalova Z. Stimuli-sensitive hydrogels in controlled and sustained drug delivery. Medicina 2003;39:19-24.
Ju XJ, Xie R, Yang L, Chu LY. Biodegradable ‘intelligent’ materials in response to physical stimuli for biomedical applications. Expert Opin Ther Pat 2009;19:493-507.
Agarwal P, Rupenthal ID. Injectable implants for the sustained release of protein and peptide drugs. Drug Discover Today 2013;18:337-49.
Rajak P, Nath LK, Bhuyan B. Liquid crystals: an approach in drug delivery. Indian J Pharma Sci 2019;81:11-21.
Hassan RM, Khairou KS, Awad AM. New aspects to physicochemical properties of polymer gels in particularly the coordination biopolymeric metal–alginate ionotropic hydrogels. In: Polymer Gels, Springer, Singapore; 2018. p. 275-354.
Qazvini NT, Bolisetty S, Adamcik J, Mezzenga R. Self-healing fish gelatin/sodium montmorillonite biohybrid coacervates: structural and rheological characterization. Biol Macromol 2012;13:2136-47.
Migneault I, Dartiguenave C, Bertrand MJ, Waldron KC. Glutaraldehyde: Behaviour in aqueous solution, reaction with proteins, and application to enzyme cross-linking. Biotech 2004;37:790-802.
Oryan A, Kamali A, Moshiri A, Baharvand H, Daemi H. Chemical cross-linking of biopolymeric scaffolds: current knowledge and future directions of cross-linked engineered bone scaffolds. Int J Biol Macromol 2018;107:678-88.
Vibha B. In-situ gel nasal drug delivery system-a review. Inter J Pharma Sci 2014;4:577-80.
Wu Y, Liu Y, Li X, Kebebe D, Zhang B, Ren J, et al. Research progress of in-situ gelling ophthalmic drug delivery system. Asian J Pharm Sci 2019;14:1-5.
Kumar L, Verma R. Chemical stability studies of bioadhesive topical gel. Int J Pharm Pharm Sci 2011;3:101-4.
Yadav KS, Rajpurohit R, Sharma S. Glaucoma: current treatment and impact of advanced drug delivery systems. Life Sci 2019;221:362-76.
Karthikeyan D, Bhowmick M, Pandey VP, Nandhakumar J, Sengottuvelu S, Sonkar S, et al. The concept of ocular inserts as drug delivery systems: an overview. Asian J Pharm 2014;2:192-200.
Morsi N, Ibrahim M, Refai H, El Sorogy H. Nanoemulsion-based electrolyte triggered in situ gel for ocular delivery of acetazolamide. Eur J Pharm Sci 2017;104:302-14.
Kakinoki S, Taguchi T. Antitumor effect of an injectable in-situ forming drug delivery system composed of a novel tissue adhesive containing doxorubicin hydrochloride. Eur J Pharm Biopharm 2007;67:676-81.
Miyazaki S, Kubo W, Itoh K, Konno Y, Fujiwara M, Dairaku M, et al. The effect of taste masking agents on in situ gelling pectin formulations for oral sustained delivery of paracetamol and ambroxol. Int J Pharm 2005;297:38-49.
Dhir S, Ali Saffi K, Kamalpuria N, Mishra D. An overview of in situ gelling system. Int J Pharm Life Sci 2016;7:5135-56.
Van Tomme SR, Hennink WE. Biodegradable dextran hydrogels for protein delivery applications. Expert Rev Med Devices 2007;4:147-64.
Basu A, Kunduru KR, Doppalapudi S, Domb AJ, Khan W. Poly (lactic acid) based hydrogels. Adv Drug Delivery Rev 2016;107:192-205.
Kubo W, Itoh K, Miyazaki S, Attwood D. Oral sustained delivery of theophylline and cimetidine from in situ gelling pectin formulations in rabbits. Drug Dev Ind Pharm 2005;31:819-25.
Madan M, Bajaj A, Lewis S, Udupa N, Baig JA. In situ forming polymeric drug delivery systems. Indian J Pharm Sci 2009;71:242-51.
Miyazaki S, Kawasaki N, Endo K, Attwood D. Oral sustained delivery of theophylline from thermally reversible xyloglucan gels in rabbits. J Pharm Pharmacol 2001;53:1185-91.
Paul S, Mondol R, Ranjit S, Maiti S. Antiglaucomatic niosomal system: recent trend in ocular drug delivery research. Int J Pharm Pharm Sci 2010;2:15-8.
Nayak AK, Bera H. In situ polysaccharide-based gels for topical drug delivery applications. In: Polysaccharide carriers for drug delivery; 2019. p. 615-38.
Kanwar N, Sinha VR. In situ forming depot as sustained-release drug delivery systems. Crit Rev Ther Drug Carrier Syst 2019;36:93-136.
Mundhada DR, Chandewar AV. An overview on in-situ gel. Res J Pharma Dosage Forms Tech 2015;7:261-5.
Kouchak M. In situ gelling systems for drug delivery. Jundishapur J Nat Pharm Prod 2014;9:e20126.
Elmowafy E, Cespi M, Bonacucina G, Soliman ME. In situ composite ion-triggered gellan gum gel incorporating amino methacrylate copolymer microparticles: a therapeutic modality for buccal applicability. Pharma Dev Tech 2019;24:1258-71.
Vashisth P, Singh H, Pruthi PA, Pruthi V. Gellan as novel pharmaceutical excipient. Handbook of Polymers for Pharmaceutical Technologies: Structure and Chemistry; 2015. p. 1-21.
Mishra A, Malhotra AV. Tamarind xyloglucan: a polysaccharide with versatile application potential. J Mater Chem 2009;19:8528-36.
Swamy NG, Abbas Z. Mucoadhesive in situ gels as nasal drug delivery systems: an overview. Asian J Pharm Sci 2012;7:168-80.
Tiwari G, Tiwari R, Sriwastawa B, Bhati L, Pandey S, Pandey P, et al. Drug delivery systems: an updated review. Int J Pharm Invest 2012;2:2-11.
Cho H, Chung D, Jeongho A. Poly (D, L-lactide-ran-ε-caprolactone)-poly (ethylene glycol)-poly (D, L-lactide-ran-ε-caprolactone) as parenteral drug-delivery systems. Biomaterials 2004;25:3733-42.
Okada M. Chemical syntheses of biodegradable polymers. Prog Polym Sci 2002;27:87-133.
Kamaly N, Yameen B, Wu J, Farokhzad OC. Degradable controlled-release polymers and polymeric nanoparticles: mechanisms of controlling drug release. Chem Rev 2016;116:2602-63.
Mäder K, Lehner E, Liebau A, Plontke SK. Controlled drug release to the inner ear: concepts, materials, mechanisms, and performance. Hearing Res 2018;368:49-66.
Gehrke SH. Synthesis, equilibrium swelling, kinetics, permeability and applications of environmentally responsive gels. In: Responsive gels: Volume transitions II, Springer, Berlin, Heidelberg; 1993. p. 81-144.
Kathe K, Kathpalia H. Film forming systems for topical and transdermal drug delivery. Asian J Pharm Sci 2017;12:487-97.
Hua S. Physiological and pharmaceutical considerations for rectal drug formulations. Front Pharmacol 2019;10:01196.
Jannin V, Lemagnen G, Gueroult P, Larrouture D, Tuleu C. Rectal route in the 21st Century to treat children. Adv Drug Delivery Rev 2014;73:34-49.
Dodou K. Exploring the unconventional routes-rectal and vaginal dosage formulations. Pharma J 2012;289:38.
D'souza C. The hot topic: a life-changing look at the change of life. Simon and Schuster; 2016.
Prasad RR, Kumar JR, Vasudha BA, Chettupalli AK. Formulation development and evaluation of allopurinol solid dispersions by solvent evaporation technique. Int J Appl Pharm 2018;10:168-71.
Mahalingam R, Li X, Jasti BR. Semisolid dosages: ointments, creams, and gels. Pharmaceutical sciences encyclopaedia: drug discovery, development, and manufacturing; 2010. p. 1-46.
Saini R, Saini S, Singh G, Banerjee A, Railmajra DS. In situ gels-new trends in ophthalmic drug delivery systems. Int J Pharm Sci Res 2015;6:386-90.
Soni V, Pandey V, Tiwari R, Asati S, Tekade RK. Design and evaluation of ophthalmic delivery formulations. In: Basic Fundamentals of Drug Delivery, Academic Press; 2019. p. 473-538.
Nakanishi K. Pore structure control of silica gels based on phase separation. J Porous Materials 1997;4:67-112.
Kumar D, Jain N, Gulati N, Nagaich U. Nanoparticles laden in situ gelling system for ocular drug targeting. J Adv Pharm Technol Res 2013;4:9-17.
Asasutjarit R, Thanasanchokpibull S, Fuongfuchat A, Veeranondha S. Optimization and evaluation of thermoresponsive diclofenac sodium ophthalmic in situ gels. Inter J Pharm 2011;411:128-35.
Wei G, Xu H, Ding PT, Zheng JM. Thermosetting gels with modulated gelation temperature for ophthalmic use: the rheological and gamma scintigraphic studies. J Controlled Release 2002;83:65-74.
Moore MM, Schober TJ, Dockery P, Arendt EK. Textural comparisons of gluten‐free and wheat‐based doughs, batters, and breads. Cereal Chem 2004;81:567-75.
Affholder M, Valiron F. Descriptive Physical Oceanography. CRC Press; 2001.
Ramotowski RS. Vapor/fuming methods. In: Lee and Gaensslen's advances in fingerprint technology, Boca Raton, FL: CRC Press; 2012. p. 114-45.
Kashyap N, Viswanad B, Sharma G, Bhardwaj V, Ramarao P, Kumar MR. Design and evaluation of biodegradable, bio-sensitive in situ gelling system for pulsatile delivery of insulin. Biomaterials 2007;28:2051-60.
Mandal S, Thimmasetty MK, Prabhushankar GL, Geetha MS. Formulation and evaluation of an in situ gel-forming ophthalmic formulation of moxifloxacin hydrochloride. Int J Pharm Invest 2012;2:78.
Nagalakshmi S, Anbarasan B, Ramesh S, Shanmuganathan S, Thanka J. An overview-stimuli sensitive hydrogels in ocular drug delivery system. J Pharm Sci Res 2015;7:818.
Rao MA. Measurement of flow and viscoelastic properties. In: Rheology of Fluid, Semisolid, and Solid Foods, Springer, Boston, MA; 2014. p. 63-159.
Wortel V, Taelman MC, Roschzttardtz F, Tharwat F. Tadros, Sandra Léonard, Cornelis Verboom. Colloid Stability; 2007.
Bansal G, Suthar N, Kaur J, Jain A. Stability testing of herbal drugs: Challenges, regulatory compliance and perspectives. Phytother Res 2016;30:1046-58.
Ubaid M, Ilyas S, Mir S, Khan AK, Rashid R, Khan MZ, et al. Formulation and in vitro evaluation of carbopol 934-based modified clotrimazole gel for topical application. An Acad Bras Cienc 2016;88:2303-17.
Sapavatu SN, Jadi RK. Formulation development and characterization of gastroretentive drug delivery systems of loratadine. Int J Appl Pharm 2019;11:91-9.
Srinu Naik Sapavatu, Rajendra Kumar Jadi. Development of floating drug delivery system for loratadine: in vitro and in vivo evaluation. Int J Pharm Sci Res 2020;11:3021-32.
Moondra S, Raval N, Kuche K, Maheshwari R, Tekade M, Tekade RK. Sterilization of pharmaceuticals: technology, equipment, and validation. In Dosage Form Design Parameters, Academic Press; 2018. p. 467-519.
Aldrich DS, Bach CM, Brown W, Chambers W, Fleitman J, Hunt D, et al. Ophthalmic preparations. US Pharmacopeia 2013;39:1-21.
Kadam S, Kondawar M, Kamble K. Formulation and evaluation of in situ gelling system of ketrolac tromethamine for ophthalmic drug delivery. Int J Pharm Thera 2010;1:64-71.
Morsi N, Ghorab D, Refai H, Teba H. Ketoroloac tromethamine loaded nanodispersion incorporated into thermosensitive in situ gel for prolonged ocular delivery. Int J Pharm 2016;506:57-67.
Leng KM, Vijayarathna S, Jothy SL, Sasidharan S, Kanwar JR. In vitro and in vivo anticandidal activities of alginate-enclosed chitosan–calcium phosphate-loaded Fe-bovine lactoferrin nanocapsules. Future Sci OA 2017;4:FSO257.
Rodriguez Hernandez J. Antimicrobial/Antifouling surfaces obtained by surface modification. In: Polymers against Microorganisms, Springer, Cham; 2017. p. 95-123.
Wang F, Yang Z, Liu M, Tao Y, Li Z, Wu Z, et al. Facile nose-to-brain delivery of rotigotine-loaded polymer micelles thermosensitive hydrogels: in vitro characterization and in vivo behavior study. Int J Pharm 2020;577:119046.
Jones DS, Yu T, Andrews GP. A statistical determination of the contribution of viscoelasticity of aqueous carbohydrate polymer networks to drug release. Carbohydr Polym 2019;206:511-9.
Jain D, Kumar V, Singh S, Mullertz A, Bar-Shalom D. Newer trends in in situ gelling systems for controlled ocular drug delivery. J Anal Pharm Res 2016;2:00022.
Bashir R, Majeed A, Ali T, Farooq S, Khan NA. Floating oral in-situ gel: a review. J Drug Delivery Ther 2019;9:442-8.
Majeed A, Khan NA. Ocular in situ gel: an overview. J Drug Delivery Ther 2019;9:337-47.
Soliman KA, Ullah K, Shah A, Jones DS, Singh TR. Poloxamer-based in situ gelling thermoresponsive systems for ocular drug delivery applications. Drug Discovery Today 2019;24:1575-86.
Pandya Y, Sisodiya D, Dashora K. Atrigel, implants and controlled released drug delivery system. Int J Biopharm 2014;5:208-13.
Mammo ZN, Flanagan JG, James DF, Trope GE. Generic versus brand-name North American topical glaucoma drops. Can J Ophthalmol 2012;47:55-61.