Efficacy and safety of travoprost alone or in combination with other agents for glaucoma and ocular hypertension: patient considerations

Ocular prodrugs: Attributes and challenges

Ocular drug delivery is one of the most attention-grabbing and challenging endeavors among the numerous existing drug delivery systems. From a drug delivery point of view, eye is an intricate organ to investigate and explore. In spite of many limitations, advancements have been made with the intention of improving the residence time or permeation of the drug in the ocular region. Poor bioavailability of topically administered drugs is the major issue pertaining to ocular drug delivery. Several efforts have been made towards improving precorneal residence time and corneal penetration, e.g. iontophoresis, prodrugs and ion-pairing, etc. Prodrug approach (chemical approach) has been explored by the formulation scientists to optimize the physicochemical and biochemical properties of drug molecules for improving ocular bioavailability. Formulation of ocular prodrugs is a challenging task as they should exhibit optimum chemical stability as well as enzymatic liability so that they are converted into parent drug after administration at the desired pace. This review will encompass the concept of derivatization and recent academic and industrial advancements in the field of ocular prodrugs. The progression in prodrug designing holds a potential future for ophthalmic drug delivery.

Prodrug strategies in ocular drug delivery

Poor bioavailability of topically instilled drug is the major concern in the field of ocular drug delivery. Efflux transporters, static and dynamic ocular barriers often possess rate limiting factors for ocular drug therapy. Different formulation strategies like suspension, ointment, gels, nanoparticles, implants, dendrimers and liposomes have been employed in order to improve drug permeation and retention by evading rate limiting factors at the site of absorption. Chemical modification such as prodrug targeting various nutrient transporters (amino acids, peptide and vitamin) has evolved a great deal of interest to improve ocular drug delivery. In this review, we have discussed various prodrug strategies which have been widely applied for enhancing therapeutic efficacy of ophthalmic drugs. The purpose of this review is to provide an update on the utilization of prodrug concept in ocular drug delivery. In addition, this review will highlight ongoing academic and industrial research and development in terms of ocular prodrug design and delivery.

Quality of life of glaucoma patients under medical therapy with different prostaglandins

PURPOSE

To assess the quality of life of glaucoma patients under medical therapy with different prostaglandin analogs.

METHODS

A cross-sectional study of consecutive glaucoma patients was designed. We assessed the patients' quality of life through the Brazilian 25-question version of the National Eye Institute Visual Functioning Questionnaire, comprising 12 subscales (general health, general vision, ocular pain, near vision, distance vision, social function, mental health, role limitations, dependency, driving, color vision, and peripheral vision) and a total composite score. Clinical features, including current medical treatment, were obtained from each patient's medical record. Three groups of patients were identified according to the prostaglandin in use: bimatoprost, latanoprost, or travoprost. The main outcome measures were: mean score in each subscale and mean total composite score.

RESULTS

The mean total composite score for the whole group was 70.60. The bimatoprost, latanoprost, and travoprost groups had the following mean composite scores, respectively: 56.56, 77.36, and 71.08 (P = 0.001, analysis of variance [ANOVA]). Latanoprost and travoprost results were similar, and both were superior to bimatoprost. Most subscales had similar results. The subscale with the lowest score for all groups was general health. Groups were homogenous and comparable.

CONCLUSION

There is a difference in the quality of life between glaucoma patients using prostaglandin analogs. It seems that bimatoprost users have lower QoL when compared to latanoprost and travoprost users.