Generic Eye Drops Research Articles

What about generic glaucoma medications and the ocular surface?

There is an ongoing debate among healthcare providers about the safety and effectiveness of generic eye drops compared to branded eye drops. Although one would expect generic eye drops to be a true copy of the original eye drop, there are surprisingly few requirements for the introduction of a generic eye drop on the market. Thus, only the concentration of the active ingredients must be identical to that of the original product. As many other factors such as bottle material, bottle shape and size and cap colour, drop size, pH, viscosity and buffer capacity can influence the efficacy, there are doubts whether generic products are truly identical to their original variants. This presentation will provide an overview of current original/generic eye drops and the challenges that patients may face when using generic variants.

The Effect of Market Competition on the Price of Topical Eye Drops

ABSTRACT Purpose To describe the relationship between the number of Federal Drug Administration (FDA)-approved manufacturers and the price change of generic and branded topical eye drops. Methods Retrospective analysis of topical eye drop medications with formulations listed in the FDA Orange Book and the National Average Drug Acquisition Cost database from 2013 to 2017. Results The most frequently prescribed generic topical drugs were glaucoma medications (34%), antimicrobials (32%), anti-inflammatories (24%), mydriatics (5%), and anesthetics (5%). The most frequently prescribed branded topical drugs were anti-inflammatories (45%), glaucoma medications (32%), antimicrobials (21%) and dry eye medications (3%). From 2013 to 2017, generic eye drops had a median price decrease of 20% (IQR 32%) while branded eye drops had a median price increase of 44% (IQR 28%) (P < .001). A significant inverse association was identified between the price change of generic eye drops and the total number of all manufacturers (r = −.41, P = .010), generic drug manufacturers (r = −.32, P = .0496), and alternative branded drug manufacturers (r = −.57, P = .002). There was no significant association between the price change of branded eye drops and number of manufacturers. Glaucoma (r = −.58, P = .039) and anti-inflammatory (r = −.69, P = .047) eye drops also had significant inverse associations with the number of generic manufacturers. Conclusion From 2013 to 2017, the price of generic eye drops decreased whereas the price of branded eye drops increased. Market competition was significantly inversely associated with price changes of generic eye drops but not branded eye drops.

The Use of Generic Medications for Glaucoma.

The use of generic medicines has grown considerably in recent years providing considerable cost savings. In England, generic items represented 11.7% of prescriptions for glaucoma and ocular hypertension in 2009, increasing to 55.2% of prescriptions in 2018. Generics can be brought to the market quickly and at low cost as manufacturers are not required to repeat animal or clinical research on active ingredients already approved for safety and efficacy. Although there is no regulatory requirement for studies comparing branded and generic eye drops, several randomised crossover studies have been performed comparing branded and generic prostaglandin analogues. While most have shown similar intraocular pressure lowering, studies are of short duration and have not evaluated visual field endpoints. Furthermore, differences in inactive ingredients, pH, viscosity, levels of particulate matter, and degradation over time have been reported. Other potential problems with generic eye drops include differences in bottle design affecting adherence, problems with supply, and the possibility that reduced revenue for innovator companies will lead to reduced investment in new drug development. This article reviews the potential advantages and disadvantages of generic antiglaucoma medications.

What is the relationship between eye drops and women in science?

AbstractDespite the multifactorial nature of glaucoma, it is evident that treatments to lower the intraocular pressure (IOP) decrease the rate of glaucomatous progression. Within the available treatments, IOP‐lowering eye drops are the far most common strategy. In 2011, the most prescribed anti‐glaucomatous eye drops, Xalatan, went out of patent and since then multiple generic eye drops has entered the market. Although it is an obvious benefit to eradicate the monopoly, the minimum requirements for the introduction of generic eye drops are worrying. Thus, increasing evidence have shown significant differences between generic anti‐glaucomatous eye drops and their brand name products. Moreover, differences in‐between the generic eye drops exist. To complicate it even more, generic Xalatan has changed and is now different from its original form. Overall, it is a jungle and only by improving research, education, and behaviour, the availability of the various treatment options will be rewarding. With a humorous, but serious, angle, the jungle of current available anti‐glaucomatous eye drops will be compared to the challenging career path of women in science.

Prospective study comparing Xalatan® eye drops and two similar generics as to the efficacy and safety profile.

To evaluate the efficacy and safety between two generic prostaglandins Lataz-Xalaprost (Greece) and the corresponding original drops (Xalatan®). In this prospective randomized study, 60 patients diagnosed with open-angle glaucoma or ocular hypertension were enrolled, who had never received antiglaucoma treatment. Subjects were divided randomly into three groups (Xalatan, Lataz, and Xalaprost groups) and they were studied over 16 weeks. At each visit, the mean applanation tonometry values and tear break-up time were measured. The Ocular Surface Disease Index questionnaire was used to evaluate patient's symptoms. There was a statistically significant difference (p < 0.001) in the mean values of the intraocular pressure between the baseline and the last visit (Xalatan group: from 23.11 ± 1.61 mmHg to 15.81 ± 1.22 mmHg, Lataz group: from 23.26 ± 1.33 mmHg to 15.80 ± 1.47 mmHg, and Xalaprost group: from 23.08 ± 1.45 mmHg to 16.08 ± 1.38 mmHg). Both generic eye drops showed mean percentage intraocular pressure reduction comparable to the standards of prostaglandin analogues (Xalatan: 31.57%, Lataz: 32.06%, and Xalaprost: 30.34%). Xalatan reduced the tear break-up time less, followed by Lataz and then by Xalaprost (Xalatan: from 8.5 to 8 s, Lataz: from 8.2 to 7.4 s, and Xalaprost: from 8.7 to 7.7 s). Xalatan presented the best safety profile, followed by Lataz and least was Xalaprost, according to Ocular Surface Disease Index questionnaire's results. No significant difference was recorded in the effectiveness of each generic prostaglandin compared to the original. Furthermore, no patient had to change medication. The differences that arose in the safety profile of the three eye drops suggest a prompt closer initial monitoring of patients who are administered generic eye drops.

The physical properties of generic latanoprost ophthalmic solutions are not identical.

To compare various characteristics of Xalatan® and five generic latanoprost ophthalmic solutions. Drop size, volume, pH values, buffer capacity, viscosity, hardness of bottles and costs were determined. Drop sizes were measured in triplicates by micropipettes, and the number of drops counted in three separate bottles of each generic product was determined. pH values were measured in triplicates by a calibrated pH meter. Buffer capacity was exploited by titrating known quantities of strong base into 2.5ml of each brand and interpolated to neutral pH. Kinematic viscosity was determined by linear regression of timed gravity flow from a vertical syringe through a 21-G cannula. The hardness of the bottles was evaluated by gradually increasing tension on a hook placed around each bottle until a drop was expelled reading the tension on an attached spring scale. Drop sizes and the number of drops in the bottles varied significantly between the generic drugs. The control value of pH in the brand version (Xalatan® ) was markedly lower compared to the generic latanoprost products. Titration of Xalatan® to neutrality required substantially more NaOH compared to the generic latanoprost products. Finally, the viscosity revealed a significant variability between brands. Remarkable differences were found in bottle shapes, bottle hardness and costs of the latanoprost generics. Generic latanoprost eye drops should not be considered identical to the original brand version as regards to drop size, volumes, pH values, buffer capacity, viscosity, hardness of bottles and costs. It is likely that these issues affect compliance and intraocular pressure (IOP)-lowering effect. Therefore, re-evaluation of the requirements for introducing generic eye drops seems reasonable.

Manchester iStent study: 3-year results and cost analysis

PurposeTo evaluate the safety, efficacy, and the cost of combined phacoemulsification and single iStent insertion in open angle glaucoma (OAG) at 3-years follow-up.MethodsThis was a prospective, uncontrolled, interventional case series. All subjects underwent single iStent implantation combined with cataract surgery by a single surgeon and were followed up over 3 years. Primary outcome measures were the reduction in intraocular pressure (IOP) and number of glaucoma drops at 1, 2, and 3 years. The costs of the procedure vs the cost of continuation of glaucoma drops were calculated and compared in patients who completed 3-years follow-up.ResultsForty-one patients were included in the study and thirty-six patients completed 3-years follow-up. Mean pre-op IOP was 21.2 mm Hg on 2.1 medications. Mean IOP was reduced to 15.9 mm Hg on 0.5 drops, 16.1 mm Hg on 1.0 drops, and 17.1 mm Hg (P<0.001) on 1.3 drops (P<0.001) at 1, 2, and 3 years, respectively. The overall cost of combined cataract surgery and iStent was estimated to be £829.32 more in total than conservative management with brand name eye drops over 3 years (£7.70 per patient per year) and £14 176.9 more if generic drops were used. (£131.3 per patient per year).ConclusionsCombined phaco-iStent proved to be a safe and effective way of managing patients with OAG over our 3-year follow-up period. The cost-effectiveness of the procedure may vary depending on whether brand name or generic eye drops are used.

Determination of phosphate concentration in glaucoma eye drops commercially available in Spain

ObjectivesTo identify and analyze the phosphate concentration in glaucoma eye drops available in Spain. Material and methodsGlaucoma medications containing phosphates were identified according to the 2013 Vademecum and the website of the Spanish Agency for Medicines and Medical Devices. Phosphate concentration was determined in these eye drops using ultraviolet molecular absorption spectrophotometry, and pH was determined using scan image analysis algorithms of pH strips. ResultsA total of 37 phosphate containing glaucoma eye drops were identified. The mean phosphate concentration was 97.72±75.52mM. The group with higher concentration of active substance was timolol (204.85±42.38mM) followed by brimonidine/timolol (200.9mM). No statistically significant difference was found between brand name (95.65±71.11mM) and generic eye drops (99.14±80mM, p=0.892). Although no statistically significant difference was found between products containing preservatives (99.24±76.78mM) and those without preservatives (85.17±72.86mM) (p=0.730), a lower phosphate concentration was observed in the preservative-free Timolol and Latanoprost. Single dose samples showed a lower phosphate concentration than multi-dose ones (102.04±75.39 vs. 22.24±2.98mM, p<0.001). The mean pH was 7.13±0.63. No statistical correlation was found between phosphate concentration and pH (r: 0.07). ConclusionThe phosphate concentration in glaucoma eye drops exceeded the tear film physiological level (1.45mM). No difference was observed between brand names and generic eye drops. Lower phosphate concentration was observed in preservative-free single dose eye drops.

Determination of phosphate concentration and pH in artificial tear drops

ObjectiveTo determine phosphate concentration and pH in artificial tear eye drops commercially available in Spain. Materials and methodsA total of 71 examples of artificial tear preparations were identified in a search of Vademecum 2014 and the Spanish Medicines Agency website. In the 24 artificial tear products containing phosphates, quantification of these was performed by ultraviolet molecular absorption spectrophotometry, and the determination of pH was performed using scan image analysis algorithms of pH strips. ResultsOf the 71 artificial tears tested, 24 contained phosphate among their excipients in the data sheet, three of which had a concentration level below detection limit (<0.1mM). The mean phosphate concentration was 17.91±23.87mM. The artificial tear sample containing a higher concentration was Colircusi Humectante (87.1mM). Lubricants based on hypromellose showed the highest phosphate concentration (41.59±32.1mM), showing statistically significant differences compared to povidone (p=0.0196) and hyaluronate (p=0.0067). Statistically significant differences were found between products containing preservatives (32.39±20.91mM), and preservative free ones (8.49±11.98mM) (p=0.0498). However, no difference was found between multidose (20.21±26.91mM) and unidose (9.31±14.39mM) samples, or between brand name (15.44±23.3mM) and generic eye drops (20.81mM). The mean pH was 6.93±0.26 (6.2–7.22). No statistical correlation was detected between phosphate concentration and pH (Spearman's Rho −0.1089 and p=0.6125). ConclusionA total of 24 (33.8%) of the 71 artificial tears contained phosphate. We believe identifying the phosphate concentration of artificial tears is useful information in order to avoid complications in high-risk patients.

Determinación de la concentración de fosfatos en los colirios antiglaucomatosos comercializados en España

ObjectivesTo identify and analyze the phosphate concentration in glaucoma eye drops available in Spain. Material and methodsGlaucoma medications containing phosphates were identified according to the 2013 Vademecum and the website of the Spanish Agency for Medicines and Medical Devices. Phosphate concentration was determined in these eye drops using ultraviolet molecular absorption spectrophotometry, and pH was determined using scan image analysis algorithms of pH strips. ResultsA total of 37 phosphate containing glaucoma eye drops were identified. The mean phosphate concentration was 97.72±75.52mM. The group with higher concentration of active substance was timolol (204.85±42.38mM) followed by brimonidine/timolol (200.9mM). No statistically significant difference was found between brand name (95.65±71.11mM) and generic eye drops (99.14±80mM, P=.892). Although no statistically significant difference was found between products containing preservatives (99.24±76.78mM) and those without preservatives (85.17±72.86mM) (P=.730), a lower phosphate concentration was observed in the preservative-free Timolol and Latanoprost. Single dose samples showed a lower phosphate concentration than multi-dose ones (102.04±75.39 vs. 22.24±2.98mM, P<.001). The mean pH was 7.13±0.63. No statistical correlation was found between phosphate concentration and pH (r: 0.07). ConclusionThe phosphate concentration in glaucoma eye drops exceeded the tear film physiological level (1.45mM). No difference was observed between brand names and generic eye drops. Lower phosphate concentration was observed in preservative-free single dose eye drops.

Determinación de la concentración de fosfatos y pH en los colirios de lágrima artificial

ObjectiveTo determine phosphate concentration and pH in artificial tear eye drops commercially available in Spain. Materials and methodsA total of 71 examples of artificial tear preparations were identified in a search of Vademecum 2014 and the Spanish Medicines Agency website. In the 24 artificial tear products containing phosphates, quantification of these was performed by ultraviolet molecular absorption spectrophotometry, and the determination of pH was performed using scan image analysis algorithms of pH strips. ResultsOf the 71 artificial tears tested, 24 contained phosphate among their excipients in the data sheet, three of which had a concentration level below detection limit (<0.1mM). The mean phosphate concentration was 17.91±23.87mM. The artificial tear sample containing a higher concentration was Colircusi Humectante (87.1mM). Lubricants based on hypromellose showed the highest phosphate concentration (41.59±32.1mM), showing statistically significant differences compared to povidone (P=.0196) and hyaluronate (P=.0067). Statistically significant differences were found between products containing preservatives (32.39±20.91mM), and preservative free ones (8.49±11.98mM) (P=.0498). However, no difference was found between multidose (20.21±26.91mM) and unidose (9.31±14.39mM) samples, or between brand name (15.44±23.3mM) and generic eye drops (20.81mM). The mean pH was 6.93±0.26 (6.2-7.22). No statistical correlation was detected between phosphate concentration and pH (Spearman's Rho −0.1089 and P=.6125). ConclusionA total of 24 (33.8%) of the 71 artificial tears contained phosphate. We believe identifying the phosphate concentration of artificial tears is useful information in order to avoid complications in high-risk patients.

Generic Drugs‐ are they as good as brand‐names?

PurposeThe aim of the present study was to investigate different characteristics of six Latanoprost generics.MethodsPrize, drop size and volume in each generic were determined. The hardness of each bottle was further evaluated using a fish weight and a hook. Finally, pH was measured and the buffer capacity evaluated by addition of NaOH.ResultsPrice, drop size and volume varied significantly between the brand version (xalatan) and the generic latanoprost products. Hence, drops sized were in the range 40–47 µl and the number of drops in each generic bottle varied between 95 and 111 drops. The embalages of each latanoprost product were different in both size and hardness. The control value of pH in the brand version (Xalatan) was 5.99 ± 0.01 (mean ± SD), whereas the generic latanoprost products had significantly higher values within the range 6.70–6.82. Hence, titration of 2.5 µl Xalatan to neutrality required 70.4 ± 0.4 nmol NaOH compared to the generic latanoprost products which required within the range 28.1–33.7 nmol NaOH.ConclusionsThe present study identifies differences among latanoprost generics such as different pH values and different buffer capacities. Moreover, the emballages varies significantly, thereby leading to critical variations in the handling of the generics. Finally, the number and size of drops in each generic were different, not to mention the prize variations between the brand version and the generics. Over all, generic eye drops should not be considered identical. Therefore, re‐evaluation of the requirements for introducing generic drugs seems reasonable.