Pilocarpine, prolonged release

Loucas, S. P. and H. M. Haddad. 1972. Solid-state ophthalmic dosage systems in effecting prolonged release of pilocarpine in the cul-de-sad. Pharm. Sci61 985-986. 

Multiple emulsions have been used to deliver active agents with prolonged release in dermatological treatments. For example, O/W/O emulsions have been used to deliver pilocarpine hydrochloride as a myopic agent in eye infections [440]. Here the active agents was placed in the internal oil phase of the O/W/O emulsion to provide an appropriate rate of release. Similar approaches have been used in other treatments, using W/O/W emulsions [440]. 

Multiple emulsions have been used to deliver active agents with prolonged release in dermatological treatments. For example, O/W/O emulsions have been used to deliver pilocarpine hydrochloride as a myopic agent in eye infections... 

S. P. Loucas and H. M. Haddad, Solid-State Ophthalmic Dosage Systems in Effecting Prolonged Release of Pilocarpine in the Cul-De-Sac, J. Pharm. Sci. 61 985 (1972). 

Drug delivery problems associated with pilocarpine, most notably low ocular bioavailability and short duration of action, continue to be significant (44). In an effort to prolong delivery and to avoid undesirable effects, an investigation was carried out on the incorporation and in vitro release of pilocarpine from a soluble film... 

An erodible implant system based on PVA has also been investigated. The bioavailability of pilocarpine was shown to be increased sixteen-fold using this system. The system showed considerable promise for prolonged drug delivery since vision is minimally affected by the presence of an insert positioned on the sclera. When the device is placed in the lower fornix, the contact area for the released drug is the sclera and little material is in contact with the cornea. 

Various lecithin-based MEs were also characterized by Hasse and Keipert [131]. The formulations were tested in terms of their physicochemical parameters (pH, refractive index, osmolality, viscosity, and surface tension) and physiological compatibility (HET-CAM and Draize test). In addition, in vitro and in vivo evaluations were performed. The tested MEs showed favorable physicochemical parameters and no ocular irritation as well as a prolonged pilocarpine release in vitro and in vivo. 

Pilocarpine is a drug commonly used in glaucoma therapy to relieve intraocular pressure (lOP), which is a cause of great discomfort to the patient. Piloplex is a sustained-release product based on an emulsion system of pilocarpine bound to a polymeric carrier [87,88]. Piloplex was shown to prolong a reduction in lOP as compared to standard pilocarpine hydrochloride drops. This is attributed to its bioadhesive properties, which keep the drug in the precorneal area longer than do conventional ocular dosage forms. 

In this formnlation, pilocarpine is bound to a polymeric material and this complex makes up the internal, dispersed phase of the emulsion system, in vitro studies have indicated that the release time of 80% of the pilocarpine from this system is 6 h compared to 80% released in only 1 h from pilocarpine hydrochloride solntion thus, the prolonged therapeutic effect is apparently due to both an enhanced pnlse entry of drng and to a prolongation of drug release from the vehicle. 

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