Effect of textured eye drop bottles on the photostability of pranoprofen 0.1% ophthalmic solution.

Context: Ophthalmic solutions are usually filled in a plastic bottle due to its durability and disposability. In Japan, photostability is one of the concerns for the quality control because an eye drop bottle must be a transparent container.

Objective: The present work studied the effect of textured eye drop bottles on its light blocking to improve the photostability of ophthalmic solutions.

Comparative studies of N-glycans and glycosaminoglycans present in SIRC (Statens Seruminstitut rabbit cornea) cells and corneal epithelial cells from rabbit eyes.

Purpose: We compared cultured Statens Seruminstitut rabbit cornea (SIRC) cells and corneal epithelial cells from rabbit eyes by analyzing their N-glycans and glycosaminoglycans (GAGs). This work is a fundamental study on the efficacy of using cultured cells instead of animals for drug development.

Materials And Methods: N-Glycans and GAGs from SIRC cell monolayers and corneal epithelial cells of rabbit eyes were analyzed by capillary electrophoresis (CE) and a combination of high-performance liquid chromatography (HPLC) and mass spectrometry.

NMR analysis of ion pair formation between timolol and sorbic acid in ophthalmic preparations.

Ion pair formation between timolol and sorbic acid was investigated using NMR spectroscopy in order to clarify their interactions within ophthalmic preparation. (13)C and (1)H NMR spectra of timolol, sorbic acid, and a mixture of the two were obtained, and the signal changes induced by pairing were observed. The carbon signals of the butylaminopropanol moiety of timolol were markedly shifted in the mixture, as were the carboxyl and conjugated carbons assigned to sorbic acid.

Improvement of the ocular bioavailability of carteolol by ion pair.

Ocular bioavailability after instillation of carteolol was investigated by ion pair formation, taking into consideration a balance between lipophilicity and water solubility. The octanol/ water partition coefficient (PC(O/W)) and the aqueous humor concentration in rabbits after instillation of carteolol containing fatty acids having not more than 6 carbons were measured. The longer carbon chain fatty acid showed the higher PC(O/W) of carteolol.

Formulation of an ophthalmic lipid emulsion containing an anti-inflammatory steroidal drug, difluprednate.

Preparation of oil-in-water (o/w) type lipid emulsion is one of the approaches to formulate drugs that are poorly water-soluble but can be dissolved in the oil phase of the emulsions. A synthetic glucocorticoid medicine, difluprednate (DFBA), is a water-insoluble compound. We formulated DFBA (0.

Preparation of stable aqueous suspension of a hydrophobic drug with polymers.

Pharmaceutical preparation of a hydrophobic aldose reductase inhibitor 5-(3-ethoxy-4-pentyloxyphenyl)-2,4-thiazolidinedione (CT112) was investigated. CT112 dissolved in a basic solution with different kinds of polymers was neutralized by acid to obtain a suspension preparation. In particular, the addition of a polymer, hydroxypropyl methyl cellulose (HPMC) provided a stable CT112 suspension with a homogeneous particle size, and there seemed to be an optimal concentration of HPMC for the stable suspension.

An HPLC method to evaluate purity of a steroidal drug, loteprednol etabonate.

Validation of an analytical method for impurities and degradation products in an active pharmaceutical ingredient is important to assessment of quality and safety in a new pharmaceutical product. In the present study, a high-performance liquid chromatographic method was validated to evaluate purity of loteprednol etabonate (LE). LE and its four related substances, major process impurities and degradation products (PJ-90, PJ-91, LE-11-keto and LE-methyl ester) were well resolved using a phenyl-stationary phase under isocratic conditions.

Improvement of the ocular bioavailability of timolol by sorbic acid.

The ocular bioavailability of timolol increased in sorbic acid solution due to ion pair formation. Its octanol/water partition coefficient also increased, suggesting the formation of a more lipophilic complex. The concentration of timolol in rabbit aqueous humor was determined after instillation of timolol ophthalmic solution containing sorbic acid.

Evaluation of ophthalmic suspensions using surface tension.

Uniformity and precision of single dose are required for ophthalmic suspensions including water-insoluble ingredients. Solid sediments formed after standing still must be immediately re-dispersible and distributed homogeneously before use. However, selection of an appropriate water-soluble polymer as suspending agent is a challenging problem.

Isolation and structure elucidation of the major photodegradation products of loteprednol etabonate.

Photodegradation of loteprednol etabonate (5), a steroid anti-inflammatory drug, in the solid state, in aqueous suspension, and in aqueous acetonitrile solution has been investigated. Analysis by HPLC showed that the profile of photodegradation products in the solid state was qualitatively similar to that in the aqueous suspension, although the profile in the aqueous acetonitrile solution was considerably different. The major photodegradation products were isolated from the aqueous suspension and the aqueous acetonitrile solution by using preparative reversed-phase HPLC and their structures were elucidated on the basis of spectroscopic data.