Atropine sulfate

Atropine sulfate is a competitive muscarinic acetylcholine receptor antagonist. IC50 value: Target: mAChR Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade (Atropa belladonna), Jimson weed (Datura stramonium), mandrake (Mandragora officinarum) and other plants of the family Solanaceae. Atropine is a competitive antagonist of the muscarinic acetylcholine receptors (acetylcholine being the main neurotransmitter used by the parasympathetic nervous system). Atropine dilates the pupils, increases heart rate, and reduces salivation and other secretions [1].

References:
[1]. http://en.wikipedia.org/wiki/Atropine

Comparison of the effects of topical and systemic atropine sulfate on intraocular pressure and pupil diameter in the normal canine eye.[Pubmed:24428364]

Vet Ophthalmol. 2015 Jan;18(1):43-9.

OBJECTIVE: To compare the effects of topical 1% Atropine sulfate and systemic 0.1% Atropine sulfate on the intraocular pressure (IOP) and horizontal pupil diameter (HPD) in the canine eye. PROCEDURES: Four groups, each containing 10 dogs of varying age, breed, and sex were treated as follows: (i) One 30 muL drop of topical 1% Atropine sulfate was applied unilaterally in each dog, (ii) A control group, one drop of 0.9% saline was used, (iii) 0.06 mg/kg Atropine sulfate was given by intramuscular injection, and (iv) Control with saline injected intramuscularly. In all groups, IOP and HPD were measured every 5 min over 60 min. RESULTS: Topical atropine significantly increased IOP in the treated eye with no change in the untreated eye. A maximum increase in IOP from 17.7 +/- 3.1 to 20.3 +/- 3.1 mmHg (14.7% increase) was obtained 23.0 +/- 14.3 min post-treatment. Maximal HPD of 12.1 +/- 1.7 mm in the treated eye occurred 46.5 +/- 6.3 min after treatment, with no increase in the untreated eye. Systemic atropine caused an increase in IOP in both eyes, showing a maximum at 15.5 +/- 10.6 min post-treatment with an IOP of 17.3 +/- 4.6 mmHg in the right eye and 17.1 +/- 5.2 mmHg in the left eye (21.8% increase in the right eye and 21.6% in the left eye). Maximal HPD was noted in both eyes 30.0 +/- 11.6 min after treatment. CONCLUSIONS: Atropine sulfate causes a significant increase in IOP when given both topically and by intramuscular injection. It should be used with caution, or indeed avoided entirely, in dogs with glaucoma or in those with a predisposition to the condition.

Formulation and characterization of atropine sulfate in albumin-chitosan microparticles for in vivo ocular drug delivery.[Pubmed:25652269]

J Pharm Sci. 2015 May;104(5):1677-90.

The overall study goal was to produce a microparticle formulation containing Atropine sulfate for ocular administration with improved efficacy and lower side effects, compared with that of the standard marketed atropine solution. The objective was to prepare an Atropine sulfate-loaded bovine serum albumin-chitosan microparticle that would have longer contact time on the eyes as well as better mydriatic and cycloplegic effect using a rabbit model. The microparticle formulation was prepared by method of spray-drying technique. The percent drug loading and encapsulation efficiency were assessed using a USP (I) dissolution apparatus. The particle sizes and zeta potential were determined using laser scattering technique and the surface morphology of the microparticles was determined using a scanning electron microscope. The product yield was calculated from relative amount of material used. In vitro cytotoxicity and uptake by human corneal epithelial cells were examined using AlamarBlue and confocal microscopy. The effects of the microparticle formulation on mydriasis in comparison with the marketed Atropine sulfate solution were evaluated in rabbit eyes. The prepared microparticle formulation had ideal physicochemical characteristics for delivery into the eyes. The in vivo studies showed that the microparticles had superior effects on mydriasis in rabbits than the marketed solutions