Long-acting injectable (LAI) parenteral formulations are becoming increasingly important in drug therapy. Therefore, reliable and discriminatory in vitro dissolution methods are needed to support formulation development and the selection of promising candidate formulations before clinical studies. In this study, triamcinolone acetonide suspensions were used as a model system to investigate how different experimental parameters influence dissolution behaviour in dialysis-membrane based setups. Drug suspensions were placed in dialysis adapters enclosed in regenerated cellulose membranes. The adapters were integrated into compendial dissolution systems (USP apparatus 1 and 2). The influence of adapter orientation, agitation, adapter size, and membrane molecular weight cut-off (MWCO) was systematically investigated. Adapter orientations were first compared under constant MWCO conditions. The effect of rotational speed was then studied separately for horizontal and vertical orientations. Adapters of different sizes were compared at constant MWCO, and membranes with different nominal MWCOs were evaluated for both orientations. The results showed that all investigated parameters influenced the dissolution behaviour. The largest differences were observed between the different adapter orientations, indicating that the experimental setup strongly affects the dissolution process. In addition, larger membrane surface areas resulted in faster dissolution, and increasing rotational speed also accelerated dissolution. Membranes with higher MWCO generally led to faster dissolution. Post hoc mathematical approaches were explored to describe the influence of rotational speed and membrane surface area and provided a first approximation of the observed trends. However, the influence of MWCO could not be adequately described. Overall, the results show that several experimental parameters affect dissolution in dialysis-based systems. A clear understanding of the underlying processes is therefore essential to select appropriate models and to develop robust and clinically relevant in vitro dissolution methods for long-acting injectable suspensions.

Melkersson-Rosenthal syndrome (MRS) is a rare granulomatous disorder classically characterized by recurrent orofacial edema, relapsing peripheral facial palsy, and fissured tongue. However, the complete triad is uncommon, and incomplete forms may create a diagnostic challenge. We report the case of a 48-year-old man with type 2 diabetes mellitus who was admitted with recurrent swelling of both lips and a fissured tongue. The symptoms had begun 15 days earlier with an episode of bilateral macrocheilitis initially attributed to a food allergy. The swelling temporarily improved with antihistamine therapy but recurred one week later. Oral examination revealed marked bilateral lip edema, a fissured tongue, and gingival inflammation, without aphthous lesions, ulceration, xerostomia, or an obvious dental infectious focus. Neurological examination showed no evidence of peripheral facial palsy or facial sensory impairment. Laboratory investigations showed no major abnormalities. Serum calcium and angiotensin-converting enzyme levels were within normal limits. Thoracoabdominopelvic computed tomography and spirometry were unremarkable. QuantiFERON-TB Gold testing and sputum GeneXpert MTB/RIF were negative. A minor salivary gland biopsy was performed to assess granulomatous inflammation and demonstrated chronic non-caseating epithelioid and giant-cell granulomatous sialadenitis without histological evidence of malignancy. Based on the recurrent macrocheilitis, fissured tongue, and compatible granulomatous histology, an incomplete form of MRS was diagnosed. The patient received intralesional triamcinolone acetonide at a dose of 40 mg once monthly for six months, resulting in marked improvement in lip swelling. This case highlights the importance of considering an incomplete form of MRS in patients with recurrent unexplained lip swelling and fissured tongue, even in the absence of facial palsy.

This report describes an 11-year-old girl who presented with a 6-month history of decreased visual acuity in the left eye without ocular pain or redness. She had a history of exposure to cats and dogs. Initial ophthalmic examination showed dense vitreous inflammatory opacities and diffuse fibroproliferative traction involving the posterior pole, but no typical granulomatous lesion was visible before surgery. The patient underwent 25-gauge pars plana vitrectomy with membrane peeling, and periocular triamcinolone acetonide (40 mg) was administered at the end of surgery for residual intraocular inflammation. During surgery, a peripheral grayish-white granulomatous lesion with associated retinal traction was identified. Paired serum and undiluted vitreous fluid testing showed elevated anti-Toxocara IgG levels, and the Goldmann-Witmer coefficient was markedly increased to 63.67, supporting local intraocular anti-Toxocara antibody production. Together with the intraoperative identification of a peripheral granulomatous lesion, these findings strongly supported the diagnosis of ocular toxocariasis. The postoperative course was uneventful, with no recurrent vitritis, new retinal lesion, retinal detachment, clinically evident macular edema, or progression of the peripheral granuloma during 12 months of follow-up. Anatomical stabilization was achieved, although visual recovery remained limited, likely because of long-standing tractional macular distortion and chronic structural damage. This case highlights that ocular toxocariasis should be considered in children with unilateral chronic vitritis and tractional vitreoretinal changes, even when a typical granuloma is not visible before surgery. Paired serum and undiluted vitreous antibody testing, together with calculation of the Goldmann-Witmer coefficient, can provide important diagnostic evidence, while vitrectomy may have both diagnostic and therapeutic value in advanced tractional cases.

Posterior segment disorders represent a leading cause of vision impairment worldwide and remain challenging to manage due to limitations in ocular drug delivery. Although intravitreal injections of triamcinolone acetonide (TA) are effective, they are invasive and require repeated administration, highlighting the need for sustained-release systems. This study aimed to develop in situ sustained-release formulations of TA using lipid liquid crystals (LLCs). Formulations were prepared with glyceryldioleate (GDO), phosphatidylcholine (PC), and 28% w/w N-methyl pyrrolidone (NMP) at PC:GDO ratios of 50:50, 40:60, and 60:40. Additionally, a TA-hydroxypropyl-β-cyclodextrin (HPβCD) complex was prepared. The formulations were characterized for rheological properties, morphology, degradation behavior, and water uptake. In-vitro release was assessed in phosphate-buffered saline (pH 7.4), while in-vivo pharmacokinetics were evaluated in rabbits, comparing a selected LLC formulation (right eye) with a TA suspension (left eye). The F5 formulation (40:60 PC: GDO) achieved sustained release of 35.4% over one month and exhibited superior stability, with 24.9% less degradation compared to F6 (60:40 PC: GDO), which showed undesirable drug crystallization. The TA-HPβCD complex demonstrated an even slower release (28%). F4 (50:50 PC: GDO) was selected as optimized formulation, demonstrated the lowest water absorption and degradation with consistent release profile. In-vivo studies further confirmed that LLCs provided a more controlled and prolonged release compared with conventional TA suspension. In conclusion, LLC-based formulations of TA offer a promising strategy for sustained intravitreal drug delivery. Their biodegradability, ease of preparation, and ability to provide prolonged therapeutic levels highlight their potential for improving the management of posterior ocular diseases.

The present study aimed to develop and validate a simple, rapid and stability-indicating high-performance liquid chromatographic (HPLC) method for the simultaneous quantification of nystatin (Nys), neomycin sulfate (NS), triamcinolone acetonide (TAC) and gramicidin D (Gr) in bulk drug samples and transferosomal gel formulations. Chromatographic separation was achieved on an Agilent Eclipse C18 (250 × 4.6 mm, 5 μm) using a mobile consisting of methanol and 0.1% orthophosphoric acid (30:70, v/v). The flow rate was maintained at 1.0 mL/min, and detection was carried out at 260 nm using a Photo Diode Analyzer (PDA) detector. Under the optimized chromatographic conditions, all four analytes were eluted with symmetrical peaks, satisfactory resolution and acceptable theoretical plate counts within a run time of 12 min. The method exhibited excellent linearity over concentration ranges of 25-150 μg/mL for TAC, 62.5-375 μg/mL for Nys, 250-1,500 μg/mL for NS and 6.25-37.5 μg/mL for Gr, with correlation coefficients greater than 0.999 for all analytes. The developed method was validated according to International Council for Harmonization guidelines and demonstrated acceptable accuracy, with percentage recoveries ranging from 98 to 102% and precision, with percentage relative standard deviation values below 2%. Forced degradation studies were performed under acidic, alkaline, oxidative, reductive, thermal, photolytic, peroxide and hydrolytic conditions. The analytes exhibited degradation ranging from ~11 to 12.1%, confirming the stability-indicating capability of the method. The proposed method is simple, accurate, precise, robust and suitable for the routine quantification of Nys, NS, TAC and Gr in bulk drug substances, transferosomal gel formulations and marketed pharmaceutical products.