OBJECTIVETo develop an RP-HPLC method for assay of pilocarpine in rabbit ocular aqueous humor.

METHODSThe RP-HPLC method was performed on a column of ODS-C(18) with the mobile phase consisting of 0.5% of triethylamine (TEA) of phosphate solutions (10 mmol/L, pH 2.5) and acetonitrile (98/2,v/v). The detection wavelength was 215 nm and flow rate was 1.0 ml/min. Ninety albino rabbits were divided into 3 groups (30 in each):group 1 received 50 microl of eye drops containing 1% generic pilocarpine, group 21% mixture pilocarpine solution consisting of aqueous sample and liposome and group 31% liposome pilocarpine, respectively. The aqueous humor was withdrawn at 5, 10, 30, 40, 60, 90, 120, 180, 240 and 360 min. Pilocarpine was extracted from aqueous humor with dichloromethane.

RESULTThe linear calibration curve was obtained in the concentration range of 0.1 - 20 microg/ml. The average recovery was (68.1+/-2.7)% (n=9). Inter-day and intra-day RSD were 4.33% and 2.87%, respectively. In three formations 1% liposome pilocarpine was the best for the areas under curve and measurable amounts.

CONCLUSIONThe RP-HPLC method is simple and reliable for pilocarpine measurement in ocular aqueous. Liposome formulation can significantly increase the bioavailability of pilocarpine in ocular aqueous.

Animals ; Aqueous Humor ; chemistry ; Chemistry, Pharmaceutical ; Chromatography, High Pressure Liquid ; Pilocarpine ; administration & dosage ; analysis ; Rabbits

OBJECTIVETo compare the action of miosis of 1% pilocarpine liposome with 1% pilocarpine solution in rabbits.

METHODS18 white rabbits were randomly divided into 3 groups. Test group received 1% pilocarpine liposome, positive control group received 1% pilocarpine solution, negative control group received liposome. Each eye drop instilled into left eye of rabbits and sterile saline solution instilled into right eye as control. The pupil diameter was measured at time intervals of beginning, 0.25, 0.5, 1, 2, 3, 4, 5, 7 hours.

RESULTSThe mean pupil diameter change of 3 groups in both eyes was not significant (P > 0.05) at beginning. The strongest action of miosis took place 0.25 h in positive control group and 0.5 h in test group after instillation. The dilation of pupil in both groups took place 1 h and 3 h, and the restoration of pupil in both groups took place at 5 h and 7 h. The mean pupil diameter of negative control group was not significant in seven hours.

CONCLUSIONSThe results suggest that 1% pilocarpine liposome improves the bioavailability and prolong the duration of its action.

Animals ; Delayed-Action Preparations ; Female ; Liposomes ; pharmacology ; Male ; Miotics ; pharmacology ; Pilocarpine ; administration & dosage ; pharmacology ; Pupil ; drug effects ; Rabbits ; Random Allocation

The study is to design chitosan-coated pilocarpine nitrate submicro emulsion (CS-PN/SE) for the development of a novel mucoadhesive submicro emulsion, aiming to prolong the precorneal retention time and improve the ocular absorption. CS-PN/SE was fabricated in two steps: firstly, pilocarpine nitrate submicro emulsion (PN/SE) was prepared by high-speed shear with medium chain triglycerides (MCT) as oil phase and Tween 80 as the main emulsifier, and then incubated with chitosan (CS) acetic solution. The preparation process was optimized by central composite design-response surface methodology. Besides the particle size, zeta potential, entrapment efficiency and micromorphology were investigated, CS-PN/SE's precorneal residence properties and miotic effect were especially studied using New Zealand rabbits as the animal model. When CS-PN/SE was administered topically to rabbit eyes, the ocular clearance and the mean resident time (MRT) of pilocarpine nitrate were found to be dramatically improved (P < 0.05) compared with PN/SE and pilocarpine nitrate solution (PNs), since the K(CS-PN/SE) was declined to 0.006 4 +/- 0.000 3 min(-1) while MRT was prolonged up to 155.4 min. Pharmacodynamics results showed that the maximum miosis of CS-PN/SE was as high as 46.3%, while the miotic response lasted 480 min which is 255 min and 105 min longer than that of PNs and PN/SE, respectively. A larger area under the miotic percentage vs time curve (AUC) of CS-PN/SE was exhibited which is 1.6 folds and 1.2 folds as much as that of PNs and PN/SE, respectively (P < 0.05). Therefore, CS-PN/SE could enhance the duration of action and ocular bioavailability by improving the precorneal residence and ocular absorption significantly.
Absorption ; Animals ; Area Under Curve ; Biological Availability ; Chitosan ; chemistry ; Cornea ; metabolism ; Emulsions ; Microscopy, Electron, Transmission ; Miotics ; administration & dosage ; chemistry ; pharmacokinetics ; Ophthalmic Solutions ; Particle Size ; Pilocarpine ; administration & dosage ; chemistry ; pharmacokinetics ; Rabbits ; Random Allocation ; Solubility ; Tears ; metabolism

PURPOSE: To screen for diabetic autonomic neuropathy of the pupil using 0.5% apraclonidine and 0.1% pilocarpine and to evaluate the early diagnostic value of this pharmacologic pupillary test by assessing the relationship between pupillary and cardiovascular autonomic neuropathies. METHODS: A total of 22 diabetic patients were recruited. Baseline pupillary diameter (PD) and the difference in PD between the test eye and the control eye before and after instillation of apraclonidine and pilocarpine were measured. All patients also underwent cardiovascular autonomic function (CAF) testing. RESULTS: Baseline PD in room light correlated with duration of diabetes mellitus (DM, p=0.049) and the presence of DM retinopathy (DMR, p=0.022). Eleven patients (50%) had positive apraclonidine tests, and two patients had positive pilocarpine tests. The patients who had positive pilocarpine tests also had positive apraclonidine tests. Patients who had a positive pupillary test had a significantly higher rate of positive CAF tests (p=0.032). CONCLUSIONS: Pupillary autonomic neuropathy was related to the duration of diabetes and the degree of DMR. There was also a significant correlation between pupillary autonomic neuropathy and cardiovascular autonomic neuropathy (CAN). Also, sympathetic nerve dysfunction occurred prior to parasympathetic dysfunction in this study. A simple pharmacologic pupillary test can help manage complications in diabetic patients because patients with pupillary autonomic dysfunction have an increased risk of CAN.
Adrenergic alpha-Agonists/administration & dosage/diagnostic use ; Adult ; Aged ; Clonidine/administration & dosage/*analogs & derivatives/diagnostic use ; Diabetic Nephropathies/*diagnosis/physiopathology ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Miosis/*chemically induced/physiopathology ; Miotics/administration & dosage/diagnostic use ; Ophthalmic Solutions ; Pilocarpine/administration & dosage/*diagnostic use ; Pupil/drug effects/*physiology ; Reproducibility of Results