Tetracyclines in ophthalmology

Stability indicating high performance thin layer chromatography method development and validation for quantitative determination of tetracycline hydrochloride in tetracycline hydrochloride active pharmaceutical ingredient (API) and its dosage forms

Simple, quick, cost-effective, and environmentally friendly analytical methods for quality assurance and control roles for different medicines, including Tetrcyclines, are most significantly needed. Also, different thin layer chromatography (TLC)-based methods for tetracycline identification exist, but high performance thin layer chromatography methods based on modern state- of- the art equipment are still nonexistent. Thus, in this study, analytical method development and verification were done by high performance thin layer chromatography (HPTLC) (using an automated equipment model) using glass plates coated with silica gel 60 F254 after treating with 10% Na2EDTA. Validation was carried out according to International Council for Harmonization (ICH) guidelines. A mobile phase formed from ethyl acetate, acetonitrile, methanol, and 1% aqueous ammonia in the composition of 4.4:19.6:10:6 volume to volume ratio (V/V) was used. Rf value, percentage recoveries, linearity ranges, limit of detection (LOD), and limit of quantitation (LOQ) for the developed HPTLC method were 0.28, 100.83-106.25%, 160-560 ng/band (r2 values of 0.9999), 31.9 ng/band, and 96.7 ng/band, respectively. The results of the sample assays conducted using the new method and the United States Pharmacopoeia (USP) high performance liquid chromatography (HPLC) method were 91.59% to 108.3% and 90.83% to 102.85%, respectively. The F test for the aforementioned methods was 2.01, which is smaller than the tabulated F value of 5.05 with 5 degrees of freedom at a 95% confidence range, proving that the newly developed HPTLC and HPLC pharmacopoeial methods can be used interchangeably.The newly developed HPTLC method is easy, economical, specific, accurate, and roboust, thus it can be employed in a range of settings that require quality control and assurance activities of tetracycline hydrochloride (TC-HCl) in bulk and ointment dosage forms.

Dry eye disease in the young: A narrative review

Dry eye disease (DED), a multifactorial ocular disease that significantly impacts quality of life, is most commonly reported in adults. This review describes the prevalence, risk factors, diagnosis and management of DED in children. A literature search, conducted from January 2000-December 2022, identified 54 relevant publications. Using similar diagnostic criteria to those reported in adults, namely standardized questionnaires and evaluation of tear film homeostatic signs, the prevalence of DED in children ranged from 5.5% to 23.1 %. There was limited evidence for the influence of ethnicity in children, however some studies reported an effect of sex in older children. Factors independently associated with DED included digital device use, duration of digital device use, outdoor time and urban living, Rates of DED were higher in children with ocular allergy and underlying systemic diseases. Compared with similar studies in adults, the prevalence of a prior DED diagnosis or a diagnosis based on signs and symptoms was lower in children, but symptoms were commonly reported. Treatment options were similar to those in adults, including lifestyle modifications, blinking, management of lid disease and unpreserved lubricants in mild disease with escalating treatment with severity. Management requires careful exploration of symptoms, medical history and the diagnosis and management of ocular comorbidities such as allergy and anterior blepharitis. Appropriately powered population-based studies are required to understand the prevalence of and risk factors for DED in children. Development of age-appropriate thresholds for signs and symptoms of DED would support better diagnosis of disease and understanding of natural history.

Effects of fluoroquinolones and tetracyclines on mitochondria of human retinal MIO-M1 cells

Our goal was to explore the detrimental impacts of ciprofloxacin (CPFX) and tetracycline (TETRA) on human retinal Müller (MIO-M1) cells in vitro. Cells were exposed to 30, 60 and 120 μg/ml of CPFX and TETRA. The cellular metabolism was measured with the MTT assay. The JC-1 and CM-H2DCFDA assays were used to evaluate the levels of mitochondrial membrane potential (MMP) and ROS (reactive oxygen species), respectively. Mitochondrial DNA (mtDNA) copy number, along with gene expression levels associated with apoptotic (BAX, BCL2-L13, BCL2, CASP-3 and CASP-9), inflammatory (IL-6, IL-1β, TGF-α, TGF-β1 and TGF-β2) and antioxidant pathways (SOD2, SOD3, GPX3 and NOX4) were analyzed via Quantitative Real-Time PCR (qRT-PCR). Bioenergetic profiles were measured using the Seahorse® XF Flux Analyzer. Cells exposed 24 h to 120 μg/ml TETRA demonstrated higher cellular metabolism compared to vehicle-treated cells. At each time points, (i) all TETRA concentrations reduced MMP levels and (ii) ROS levels were reduced by TETRA 120 μg/ml treatment. TETRA caused (i) higher expression of CASP-3, CASP-9, TGF-α, IL-1B, GPX3 and SOD3 but (ii) decreased levels of TGF-B2 and SOD2. ATP production and spare respiratory capacity declined with TETRA treatment. Cellular metabolism was reduced with CPFX 120 μg/ml in all cultures and 60 μg/ml after 72 h. The CPFX 120 μg/ml reduced MMP in all cultures and ROS levels (72 h). CPFX treatment (i) increased expression of CASP-3, CASP-9, and BCL2-L13, (ii) elevated the basal oxygen consumption rate, and (iii) lowered the mtDNA copy numbers and expression levels of TGF-B2, IL-6 and IL-1B compared to vehicle-control cells. We conclude that clinically relevant dosages of bactericidal and bacteriostatic antibiotics can have negative effects on the cellular metabolism and mitochondrial membrane potential of the retinal MIO-M1 cells in vitro. It is noteworthy to mention that apoptotic and inflammatory pathways in exposed cells were affected significantly This is the first study showing the negative impact of fluoroquinolones and tetracyclines on mitochondrial behavior of human retinal MIO-M1 cells.

Corneal staining after treatment with topical tetracycline

PURPOSE

The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline.

METHODS

A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of bacterial sensitivity testing. After 3 weeks of intensive treatment, the donor cornea was stained with a brownish hue, which was ascribed to the tetracycline drops.

RESULTS

One patient with crystalline keratopathy developed corneal staining after intensive treatment with topical tetracycline eye drops. After a year of follow-up, the staining of the cornea had not changed significantly.

CONCLUSION

Hourly topical tetracycline eye drops may induce corneal pigmentation. To our knowledge, this is the first published case report of corneal staining caused by tetracycline eye drops.

Syndrome KID (Keratitis-Ichtyosis-Deafness) : hypothèse pathogénique de l’atteinte oculaire

KID is a rare ectodermal syndrome of unknown etiology. It is characterized by vascular keratitis (K), congenital ichthyosis (I) and neurosensorial deafness (D). We report the cases of three patients with KID syndrome who all had typical vascular keratitis responsible for photophobia and impaired visual acuity, and severe meibomian dysfunction associated with hyperkeratotic lid borders. The authors believe that meibomian dysfunction plays an important role in the pathogenesis of ocular lesions. Consequently, patients were treated with oral minocycline, topical steroids and artificial tears. This treatment proved to significantly reduce ocular discomfort.

The eye and skin disease

Ocular abnormalities associated with disease of the skin may involve any part of the eye or its adnexae. This review will discuss:

Diagnosis and management of chronic blepharokeratoconjunctivitis in children

PURPOSE

To describe the history, symptoms, and clinical signs and discuss the treatment of blepharokeratoconjunctivitis.

METHODS

Eight children (five girls and three boys), ranging in age from 3.5-13 years, were clinically diagnosed with blepharokeratoconjunctivitis. Microbiology studies were performed in four of the eight children. Treatment consisted of lid hygiene, oral erythromycin suspension, and preservative-free steroids. Duration of therapy was directed by clinical improvement.

RESULTS

Average age at onset was 3.2 years (range: 0.5-8 years). Lid disease, conjunctival redness, and inferior superficial corneal vascularization were consistent features (100%). Other signs were punctate corneal epithelial staining, inferior subepithelial vascularization and infiltrate, conjunctival phlyctenules, corneal phlyctenules, and circumferential pannus. Microbiology testing demonstrated coagulase-negative staphylococcus and Propionibacterium acnes. Average follow-up was 8.3 months (range: 2-23 months). All patients had relief of symptoms within 2-3 weeks. Clinical signs took more time to regress but all had progressive improvement of the ocular surface by 2 months. Blepharokeratoconjunctivitis reactivated in all patients during follow-up, and repeat therapy was administered.

CONCLUSION

Blepharokeratoconjunctivitis in childhood is a chronic inflammatory process that can have different presentations. It can be successfully treated with oral erythromycin and topical steroids.

Efficacy of doxycycline and tetracycline in ocular rosacea

We compared the effects of doxycycline and tetracycline hydrochloride on the subjective symptoms in ocular rosacea. Twenty-four patients with symptomatic ocular rosacea were randomly assigned to two groups and treated with doxycycline 100 mg/day (group 1, 16 patients) or tetracycline hydrochloride 1 g/day (group 2, eight patients). The dosages of each drug were gradually tapered and discontinued according to symptomatic response. At each examination all the manifesting symptoms were scored by the patients. Patients were followed up from six weeks to three years. After six weeks of drug treatment, all patients except one had symptomatic improvement. Although most of the scores of the symptoms were significantly decreased in both groups, greater symptomatic relief occurred in the tetracycline hydrochloride-treated patients (P = .041). However, after three months of treatment there was no significant difference in symptoms between the two groups. Gastrointestinal tract complications occurred in two of the 16 patients (12.5%) in group 1 and in three of the eight patients (37.5%) in group 2. Both tetracycline hydrochloride and doxycycline can control the symptoms of ocular rosacea.

The use of doxycycline and tetracycline in ocular rosacea

The authors compared the effects of doxycycline and tetracycline hydrochloride on subjective symptoms in ocular rosacea. Twenty-four patients with symptomatic ocular rosacea were prospectively treated with doxycycline 100 mg/day (group 1, n=16) or tetracycline hydrochloride 1g/day (group 2, n=8). The dosages of each drug were gradually tapered and discontinued according to symptomatic response. Patients were followed from six weeks to three years. In group 1, 15 patients (94%) had symptomatic improvement (12 patients were asymptomatic and three symptomatically improved), and two patients (13%) had gastrointestinal tract (GIT) complications followed by discontinuation of medication. In group 2, seven of the eight patients (87%) were asymptomatic and one patient (13%) had symptomatic improvement; three patients discontinued the use of tetracycline as a result of GIT complaints. This study indicates that both tetracycline hydrochloride and doxycycline can control the symptoms of ocular rosacea.

Childhood rosacea

Rosacea usually occurs in adults and rarely has been noted in children. We recently observed three children with rosacea, all of whom responded dramatically to systemic and topical antibiotics. Rosacea in childhood must be distinguished from other erythematous facial disorders, most commonly acne, granulomatous perioral dermatitis, and sarcoidosis. The distribution of facial lesions; the presence of telangiectasias, flushing, and pustules; and the appearance of lesional biopsy sections and the ocular lesions, if present, allow differentiation of rosacea from other facial eruptions.

Tetracyclines inhibit connective tissue breakdown: new therapeutic implications for an old family of drugs

Tetracyclines have long been considered useful adjuncts in peridontal therapy based on their antimicrobial efficacy against putative periodontopathogens. However, recently these drugs were found to inhibit mammalian collagenases and several other matrix metalloproteinases (MMPs) by a mechanism independent of their antimicrobial activity. Evidence is presented that this property may be therapeutically useful in retarding pathologic connective tissue breakdown, including bone resorption. The experiments leading to this discovery are described and possible mechanisms are addressed, including the specificity of tetracyclines' anti-collagenase activity, the role of the drugs' metal ion (Zn2+, Ca2+)-binding capacity, and the site on the tetracycline molecule responsible for this nonantimicrobial property. Of extreme interest, the tetracycline molecule has been chemically modified in multiple ways, generating a new family of compounds called CMTs (chemically modified tetracyclines) that lack antimicrobial but still retain anti-collagenase activity. The first of these CMTs, 4-de-di-methylaminotetracycline, was found not to produce a major side-effect of antimicrobial tetracycline therapy--its administration to experimental animals did not result in the emergence of tetracycline-resistant microorganisms in the oral flora and gut. Numerous examples of the clinical potential of this non-antimicrobial property of tetracyclines in the treatment of periodontal and several medical diseases (e.g., sterile corneal ulcers, rheumatoid arthritis, skin bullous lesions, tumor-induced angiogenesis and metastasis) are discussed.

Lipid synthesis in vitro by rabbit Meibomian gland tissue and its inhibition by tetracycline

Rabbit Meibomian gland tissue was incubated with radioactive acetate, propionate, valine, leucine or isoleucine. The time-course of incorporation of radioactivity into total lipids from acetate and isoleucine was studied in Hanks' or Krebs medium. Incorporation of acetate or isoleucine into lipid classes was followed by TLC, and of acetate label into individual fatty acids and alcohols by GLC with radioactivity detection. Radioactivity was highest in the minor acid components C16:1 and C18:1. Levels in branched fatty acids fell with chain length, reflecting the time-course of successive chain elongations. Use of amino acids or propionate as precursors suggested that molecules containing a specific branched structure were preferentially incorporated; this indicates a binding preference at the level of the fatty acid synthase which might explain the very high proportion of anteiso-branched structures in the rabbit secretion. Incorporation of label into total lipids was significantly reduced by tetracycline in the medium, with 50% reduction at about 1.5 mg/ml for acetate and 0.7 mg/ml for isoleucine.

The pregnant woman's eye

The effects of pregnancy on the eye fall into three categories. Nonpathological physiologic changes in pressures, corneal sensitivity and thickness, and visual function can occur. Pathologic conditions reported to develop during pregnancy include central serous chorioretinopathy, hypertensive and vascular disorders, and uveal melanoma. Pregnancy also can affect pre-existing ocular conditions, such as diabetic retinopathy, tumors, and a variety of immunological disorders and can have beneficial effects on such pre-existing conditions as glaucoma. This review covers ocular disorders in these three categories, and summarizes the systemic changes of pregnancy and the effects of ocular medications on the fetus.

Ocular rosacea

The demographic, clinical, and histopathologic characteristics of ocular rosacea are reviewed, with emphasis on examination of the skin in patients with external ocular disease. Since no single clinical or pathological hallmark of rosacea exists, a proposed point system for diagnosis is presented. Studies of pathogenesis reveal that no single unifying hypothesis accounts for all the expressions of ocular rosacea. Reports of treatment with tetracycline and other antibiotics demonstrate efficacy, although the mechanisms of action of these drugs are not known. More recently, other classes of drugs, including isotretinoin and hexachlorocyclohexane, have proven to be effective in dermatologic manifestations of rosacea, but effects on ocular manifestations are unknown.