Abdurrahman Fahmy

Voriconazole (VCZ) is a well-known broad spectrum triazole antifungal, mainly used orally and intravenously. The study aimed to formulate VCZ into ultradeformable elastosomes for the topical treatment of ocular fungal keratitis. Different formulae were prepared using a modified ethanol injection method, employing a 3 Box-Behnken design. They were characterized by measuring their entrapment efficiency (EE%), particle size (PS), polydispersity index (PDI) and zeta potential (ZP). The optimized formula was subjected to further investigations and evaluation studies. The prepared vesicles had satisfactory EE%, PS, PDI and ZP values. The numerical optimization process suggested an optimal elastosomal formula (OE) composed of phosphatidyl choline and brij S100 at the weight ratio of 3.62: 1, 0.25%w/v hyaluronic acid and 5% (percentage from phosphatidyl choline/brij mixture) polyvinyl alcohol. It had high EE (72.6%), acceptable PS and PDI (362.4 nm and 0.25, respectively) and highly negative ZP of -41.7 mV. OE exhibited higher elasticity than conventional liposomes, with acceptable stability for three months. Transmission electron microscopy demonstrated the spherical morphology of vesicles with an external transparent coat of Hyaluronic acid. OE was expected to cause no ocular irritation or blurring in vision as reflected by pH and refractive index measurements. The histopathological study revealed the safety of OE for ocular use. The fungal susceptibility testing using demonstrated the superiority of OE to VCZ suspension, with greater and more durable growth inhibition. Therefore, OE can be regarded as a promising formula, achieving both safety and efficacy.

Voriconazole (VRC) is a broad spectrum, second generation triazole antifungal. The main use of VRC is via the oral and intravenous route. The study aimed to formulate VRC into ternary micellar systems (TMSs) for the topical treatment of ocular mycosis. TMSs were successfully prepared by water addition/solvent evaporation method, applying a 3-factor D-optimal design. The numerical optimization process suggested an optimal formula (OTMS) composed of total Pluronics to drug weight ratio of 22.89: 1, 1:1 weight ratio of Pluronic® P123 and F68, and 2% w/v of Labrasol. OTMS had high solubilization efficiency of 98.0%, small micellar size of 21.8 nm and suitable zeta potential and polydispersity index values of -9.0 mV and 0.261, respectively. OTMS exhibited acceptable stability for 3 months. Transmission electron microscopy demonstrated the spherical morphology of micelles. OTMS was expected to cause no ocular irritation or blurring in vision as reflected by pH and refractive index measurements. The histopathological study revealed the safety of OTMS for ocular use. The fungal susceptibility testing using Candida albicans demonstrated the superiority of OTMS to VRC suspension, with greater and more durable growth inhibition. Therefore, ocular application of optimized VRC-loaded TMSs can be a promising treatment for ocular mycosis.

Haloperidol (Hal) is a well-known typical antipsychotic. Hepatic first pass metabolism leads to its limited oral bioavailability. This study aimed at enhancing transdermal delivery of Hal via spanlastic formulae. Hal-loaded spanlastics of Span®60 and an edge activator (EA) were successfully prepared by ethanol injection method according to a 3.4 full factorial design. In this design, independent variables were X, EA type, and X, Span®60 to EA ratio. Y, percentage entrapment efficiency (EE%); Y, particle size (PS); Y, deformability index (DI); and Y, percentage drug released after 4h (Q4h), were chosen as dependent variables. The Fourier-transform infrared spectral analysis showed no considerable chemical interaction between Hal and the used excipients. Both factors affected significantly all the responses except DI. Desirability of each prepared formula was calculated based on maximizing EE% and Q4h and minimizing PS. Formula F6, with X, Tween®80, and X, 8:2, had the highest desirability value followed by F7, with X, Tween®80, and X, 6:4, and both were chosen as selected formulae (SF) for further investigation. F6 (having more entrapped Hal), F7 (of smaller PS), and Hal solution in propylene glycol were subjected to ex vivo permeation test through newborn rat skin. Both formulae showed marked enhancement in drug permeation compared with drug solution. The significantly higher Q and J of F7 from F6 may indicate that the smaller particle size aided more than higher entrapment in achieving a higher permeation for Hal of 3.5±0.2μg/cm.h. These results are promising for further investigation of this formula.

Haloperidol (Hal) is one of the widely used antipsychotic drugs. When orally administered, it suffers from low bioavailability due to hepatic first pass metabolism. This study aimed at developing Hal-loaded penetration enhancer-containing spanlastics (PECSs) to increase transdermal permeation of Hal with sustained release. PECSs were successfully prepared using ethanol injection method showing reasonable values of percentage entrapment efficiency, particle size, polydispersity index and zeta potential. The statistical analysis of the ex vivo permeation parameters led to the choice of F1L - made of Span 60 and Tween 80 at the weight ratio of 4:1 along with 1% w/v Labrasol - as the selected formula (SF). SF was formulated into a hydrogel by using 2.5% w/v of HPMC K4M. The hydrogel exhibited good in vitro characteristics. Also, it retained its physical and chemical stability for one month in the refrigerator. The radiolabeling of SF showed a maximum yield by mixing of 100 µl of diluted formula with 50 µl saline having 200 MBq of Tc and containing 13.6 mg of reducing agent (NaBH) and volume completed to 300 µl by saline at pH 10 for 10 min as reaction time. The biodistribution study showed that the transdermal Tc-SF hydrogel exhibited a more sustained release pattern and longer circulation duration with pulsatile behavior in the blood and higher brain levels than the oral Tc-SF dispersion. So, transdermal hydrogel of SF may be considered a promising sustained release formula for Hal maintenance therapy with reduced dose size and less frequent administration than oral formula.