Determination of Hyaluronic Acid in a Chitosan-Based Formulation by RP C18 and HILIC LC–ESI-MS: an Evaluation of Matrix Effect

Development and Validation of a RP-HPLC Method for the Simultaneous Determination of Silver Sulfadiazine and Sodium Hyaluronate in the Presence of Methyl and Propyl Paraben in a Pharmaceutical Cream for Burns

A direct and precise isocratic RP-HPLC method for simultaneous determination of silver sulfadiazine (SSD) and sodium hyaluronate (SH) in the presence of methyl (MP) and propyl parabens (PP) was developed and validated. Agilent chromatograph with X-Select C18 column (250 × 4.6 mm2, 5 μm) was used. Chromatographic separation was achieved using a mobile phase consisting of acetonitrile and 0.05 M phosphate buffer (pH 5.0 to which added triethyl amine 0.5 ml/L), at a ratio 35: 65 v/v. Elution was used at flow rate of 1.0 mL/min at ambient temperature with UV detection at 205 nm. The retention times for SH, SSD, MP and PP were 1.49, 3.3, 6.7 and 19.5 min, respectively. The presented chromatographic method was fully validated in accordance with ICH requirements, it was valid over linearity ranges of (0.80-100.00 μg/mL) and (3.20-100.00 μg/mL) for SSD and SH, respectively. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges and the sensitivity of the method, as the limits of detection and quantification for each active ingredient was also determined. The validated method was successfully applied for the quantification of SSD and SH in pharmaceutical cream formulation and the mean recovery % ± SD were 100.93 ± 0.985 and 100.05 ± 0.668 for SSD and SH; respectively, indicating satisfactory accuracy of the method.

Photoprotection Against UV-Induced Skin Damage Using Hyaluronic Acid Produced by Lactiplantibacillus plantarum and Enterococcus durans

Exposure to ultraviolet (UV) radiation is one of the major factors that causes skin aging, erythema, sunburns, and skin cancer. This study aimed to select probiotic bacterial isolates able to produce high yield of hyaluronic acid (HA) to be employed for skin photoprotection and other possible biological applications. The selected isolates K11 and St3 were able to produce the highest yields of HA 4.8 and 4.4 mg/ml, respectively. Both isolates were identified as Enterococcus durans strain K11 and Lactiplantibacillus plantarum strain St3 using 16S rRNA gene sequencing. The antioxidant activity of HA produced by E. durans strain K11 and L. plantarum strain St3 was (65.4 0.2%) and (66.6 0.1%), respectively. The viability of UVB-irradiated keratinocytes pre-treated with HA produced by E. durans strain K11 and L. plantarum strain St3 was 91.3 and 91.4%, respectively, compared with the control. While the viability of UVB-irradiated keratinocytes post-treated with HA produced by E. durans strain K11 and L. plantarum strain St3 was 86 and 88.5%, respectively. To the best of our knowledge, this is the first recordation of HA production by Enterococcus durans and Lactiplantibacillus plantarum which revealed a significant radioprotection of the human keratinocytes against UVB radiation.

Quantification of the actual composition of polymeric nanocapsules: a quality control analysis

Nanocapsules (NCs) are drug delivery nanosystems that contain an oily core, stabilized by a surfactant, and surrounded by a polymeric shell. The assembling of the components is based on physical and physicochemical forces, and, hence, usually, only a fraction of each component is finally part of the NCs' structure, while the remaining amount might be solubilized or forming micelles in the NCs' suspending medium. Usually, reports on the characterization of nanostructures simply indicate the association efficiency of the loaded drugs instead of their complete final composition. In this work, we have developed a liquid chromatography (LC) mass spectrometry (MS) methodology that allows the quantification of all the components of a series of NCs prepared by different techniques, namely DL-α-tocopherol; D-α-tocopherol polyethylene glycol 1000 succinate; benzethonium; lecithin; hexadecyltrimethylammonium; 1,2-dioleoyl-3-trimethylammoniumpropane; caprylic/capric triglycerides; macrogol 15-hydroxystearate; polysorbate 80; polysialic acid; hyaluronic acid; and polyethylene glycol polyglutamic acid. The LC-MS method was validated in terms of linearity (0.9383 < r² < 0.9997), quantification limits, and recoveries of the isolated NCs' and waste fractions. The final composition of the isolated NCs was found to strongly depend on their composition and preparation technique. In our view, the rigorous quantification of the exact composition of nanosystems is essential for the progress of nanotechnology. This quantitative analysis will allow researchers to draw more accurate conclusions about the influence of the nanosystems' composition on their biological performance.

Applications of Hyaluronic Acid in Ophthalmology and Contact Lenses

Hyaluronic acid (HA) is a glycosaminoglycan that was first isolated and identified from the vitreous body of a bull’s eye. HA is ubiquitous in the soft connective tissues of animals and therefore has high tissue compatibility for use in medication. Because of HA’s biological safety and water retention properties, it has many ophthalmology-related applications, such as in intravitreal injection, dry eye treatment, and contact lenses. Due to its broad range of applications, the identification and quantification of HA is a critical topic. This review article discusses current methods for analyzing HA. Contact lenses have become a widely used medical device, with HA commonly used as an additive to their production material, surface coating, and multipurpose solution. HA molecules on contact lenses retain moisture and increase the wearer’s comfort. HA absorbed by contact lenses can also gradually release to the anterior segment of the eyes to treat dry eye. This review discusses applications of HA in ophthalmology.

A Sensitive Chromatographic Method for Hyaluronate Quantification Applied to Analyze the Desorption Behavior on Contact Lenses

Background:

Sodium hyaluronate (NaHA) is generally supplemented in products related to contact lenses for increasing comfort during wearing. The quantity of sodium hyaluronate and the material of lenses affect the retention of sodium hyaluronate on the contact lenses.

Methods:

We developed a convenient and sensitive but unconventional chromatographic method to quantify sodium hyaluronate and analyze its release behavior from contact lenses. The reverse-phase chromatography eluted sodium hyaluronate with high molecular masses in the shortest time and could separate salt and small compounds from sodium hyaluronate.

Results:

This method could accurately quantify sodium hyaluronate with diverse molecular sizes. Because sodium hyaluronate was eluted in a narrow time frame, sensitivity was significantly enhanced, and the limit of detection of this method was 0.45 μg/mL. According to this quantitation method, the attached quantity of sodium hyaluronate is related to the water content of the material. Furthermore, a material test indicated that the release efficiency of sodium hyaluronate depends on the material of lenses. Nonionic Polymacon had a longer half-life in the sodium hyaluronate release curve than negative Methafilcon A and silicone hydrogel.

Conclusion:

This hyaluronate quantification method is a fast, sensitive and accurate method, making it suitable for the in vitro hyaluronate research without further derivatization.

Recent advances in the application of hydrophilic interaction chromatography for the analysis of biological matrices

Hydrophilic interaction chromatography (HILIC) is being increasingly used for the analysis of hydrophilic compounds in biological matrices. The complexity of biological samples demands adequate sample preparation procedures, specifically adjusted for HILIC analyses. Currently, most bioanalytical assays are performed on bare silica and ZIC-HILIC columns. Trends in HILIC for bioanalysis include smaller particle sizes and miniaturization of the analytical column. For complex biological samples, multidimensional techniques can separate and identify more compounds than 1D separations. The high volatility of the mobile phase, the added separation power and high sensitivity make MS the detection method of choice for bioanalysis using HILIC, although other detectors such as evaporative light scattering detection, charged aerosol detection and nuclear magnetic resonance have been reported.