Cosmeceutical formulations of pro-vitamin E phosphate: In-vitro release testing and dermal penetration into excised human skin.

Long-term exposure to solar radiation can lead to skin damage such as photoageing, and photocarcinogenesis. This can be prevented by topically applying α-tocopherol phosphate (α-TP). The major challenge is that a significant amount of α-TP needs to reach viable skin layers for effective photoprotection. This study aims to develop candidate formulations of α-TP (gel-like, solution, lotion, and gel), and investigate formulation characteristics' effect on membrane diffusion and human skin permeation. All the formulations developed in the study had an appealing appearance and no signs of separation. All formulations had low viscosity and high spreadability except the gel. The flux of α-TP through the polyethersulfone membrane was the highest for lotion (6.63 ±â€¯0.86 mg/cm2/h), followed by control gel-like (6.14 ±â€¯1.76 mg/cm2/h), solution (4.65 ±â€¯0.86 mg/cm2/h), and gel (1.02 ±â€¯0.22 mg/cm2/h). The flux of α-TP through the human skin membrane was numerically higher for lotion compared to the gel-like (328.6 vs.175.2 µg/cm2/h). The lotion delivered 3-fold and 5-fold higher α-TP in viable skin layers at 3 h and 24 h, respectively, compared to that of the gel-like. The low skin membrane penetration rate and deposition of α-TP in viable skin layers were observed for the solution and gel. Our study demonstrated that dermal penetration of α-TP was influenced by characteristics of formulation such as formulation type, pH, and viscosity. The α-TP in the lotion scavenged higher DPPH free radicals compared to that of gel-like (almost 73% vs. 46%). The IC50 of α-TP in lotion was significantly lower than that of gel-like (397.2 vs. 626.0 µg/mL). The preservative challenge test specifications were fulfilled by Geogard 221 and suggested that the combination of benzyl alcohol and Dehydroacetic Acid effectively preserved 2% α-TP lotion. This result confirms the suitability of the α-TP cosmeceutical lotion formulation employed in the present work for effective photoprotection.

Spectroscopic and HPLC methods for the determination of alendronate in tablets and urine.

Two methods (spectrophotometric and HPLC) have been developed and validated for the analysis of alendronate sodium in tablet dosage form. Both methods depend on the ability of alendronate sodium to react with o-phthalaldehyde (OPA) at basic pH to produce a light-absorbing derivative. The derivative was found to possess absorption maximum at 330nm where neither the derivatizing agent nor the analyte had any absorption. Thus, spectroscopic method was based on the derivatization-induced absorption of alendronate sodium at 333nm. The HPLC method was based on separation of the formed derivative from other ingredients in tablets with detection at 333nm. Both methods were satisfactory with regard to accuracy, prescion and linearity. Moreover, a HPLC method with fluorescence detection (HPLC-FD) was developed for the quantification of alendronate sodium in urine. The method was also based on the derivatization of alendronate with OPA, but fluorescence detection was employed. Linearity, recovery, selectivity, prescision and sensitivity were satisfactory for the proposed HPLC-FD method. Yet a new quantification limit (0.6ngml(-1)) for alendronate in urine was achieved.